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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM 10-Q
☒    QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the quarterly period ended SeptemberJune 30, 20172023

or

TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
☐    TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the transition period from                    to                    


alliantenergylogo0930201710q.jpgalliantenergylogo.jpg

Commission
File Number
Name of Registrant, State of Incorporation,
Address of Principal Executive Offices and Telephone Number
IRS Employer
Identification Number
1-9894ALLIANT ENERGY CORPORATION39-1380265
(a Wisconsin corporation)
4902 N. Biltmore Lane
Madison, Wisconsin 53718
Telephone (608) 458-3311
1-4117INTERSTATE POWER AND LIGHT COMPANY42-0331370
(an Iowa corporation)
Alliant Energy Tower
Cedar Rapids, Iowa 52401
Telephone (319) 786-4411
0-337WISCONSIN POWER AND LIGHT COMPANYName of Registrant, State of Incorporation, Address of Principal Executive Offices, Telephone Number, Commission File Number, IRS Employer Identification Number

ALLIANT ENERGY CORPORATION
(a Wisconsin Corporation)
4902 N. Biltmore Lane
Madison, Wisconsin 53718
Telephone (608) 458-3311
Commission File Number - 1-9894
IRS Employer Identification Number - 39-1380265

INTERSTATE POWER & LIGHT COMPANY
(an Iowa corporation)
Alliant Energy Tower
Cedar Rapids, Iowa 52401
Telephone (319) 786-4411
Commission File Number - 1-4117
IRS Employer Identification Number - 42-0331370

WISCONSIN POWER & LIGHT COMPANY
(a Wisconsin corporation)
4902 N. Biltmore Lane
Madison, Wisconsin 53718
Telephone (608) 458-3311
Commission File Number - 0-337
IRS Employer Identification Number - 39-0714890
(a Wisconsin corporation)
4902 N. Biltmore Lane
Madison, Wisconsin 53718
Telephone (608) 458-3311
This combined Form 10-Q is separately filed by Alliant Energy Corporation, Interstate Power and Light Company and Wisconsin Power and Light Company. Information contained in the Form 10-Q relating to Interstate Power and Light Company and Wisconsin Power and Light Company is filed by each such registrant on its own behalf. Each of Interstate Power and Light Company and Wisconsin Power and Light Company makes no representation as to information relating to registrants other than itself.

Securities registered pursuant to Section 12(b) of the Act:
Alliant Energy Corporation, Common Stock, $0.01 Par Value, Trading Symbol LNT, Nasdaq Global Select Market

Indicate by check mark whether the registrantsregistrant (1) havehas filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrants wereregistrant was required to file such reports), and (2) havehas been subject to such filing requirements for the past 90 days.
Alliant Energy Corporation - Yes No
Interstate Power and Light Company - Yes ☒ No ☐
Wisconsin Power and Light Company - Yes ☒ No ☐

Indicate by check mark whether the registrants haveregistrant has submitted electronically and posted on their corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrants wereregistrant was required to submit and post such files).
Alliant Energy Corporation - Yes No
Interstate Power and Light Company - Yes ☒ No ☐
Wisconsin Power and Light Company - Yes ☒ No ☐
Indicate by check mark whether the registrants areregistrant is a large accelerated filers,filer, an accelerated filers,filer, a non-accelerated filers,filer, a smaller reporting companies,company, or an emerging growth companies.company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.
Alliant Energy Corporation - Large Accelerated Filer ☒ Accelerated Filer ☐ Non-accelerated Filer ☐ Smaller Reporting Company ☐ Emerging Growth Company ☐
Large Accelerated FilerAccelerated FilerNon-accelerated FilerSmaller Reporting CompanyEmerging Growth Company
Alliant Energy Corporation
Interstate Power and Light Company
Wisconsin Power and Light Company
Interstate Power and Light Company - Large Accelerated Filer ☐ Accelerated Filer ☐ Non-accelerated Filer ☒ Smaller Reporting Company ☐ Emerging Growth Company ☐
Wisconsin Power and Light Company - Large Accelerated Filer ☐ Accelerated Filer ☐ Non-accelerated Filer ☒ Smaller Reporting Company ☐ Emerging Growth Company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.
Alliant Energy Corporation ☐
Interstate Power and Light Company ☐
Wisconsin Power and Light Company ☐

Indicate by check mark whether the registrants areregistrant is a shell companiescompany (as defined in Rule 12b-2 of the Exchange Act).
Alliant Energy Corporation - Yes No
Interstate Power and Light Company - Yes ☐ No ☒
Wisconsin Power and Light Company - Yes ☐ No ☒
Number of shares outstanding of each class of common stock as of SeptemberJune 30, 2017:2023:
Alliant Energy Corporation, Common Stock, $0.01 par value, 252,719,092 shares outstanding
Interstate Power and Light Company, Common Stock, $2.50 par value, 13,370,788 shares outstanding (all outstanding shares are owned beneficially and of record by Alliant Energy Corporation)
Wisconsin Power and Light Company, Common Stock, $5 par value, 13,236,601 shares outstanding (all outstanding shares are owned beneficially and of record by Alliant Energy Corporation)


Alliant Energy CorporationCommon stock, $0.01 par value, 231,204,360 shares outstanding
Interstate Power and Light CompanyCommon stock, $2.50 par value, 13,370,788 shares outstanding (all of which are owned beneficially and of record by Alliant Energy Corporation)
Wisconsin Power and Light CompanyCommon stock, $5 par value, 13,236,601 shares outstanding (all of which are owned beneficially and of record by Alliant Energy Corporation)




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DEFINITIONS
The following abbreviations or acronyms used in this Form 10-Qreport are defined below:
Abbreviation or AcronymDefinitionAbbreviation or AcronymDefinition
20162022 Form 10-KCombined Annual Report on Form 10-K filed by Alliant Energy, IPL and WPL for the year ended Dec. 31, 20162022ITCIUBITC Midwest LLCIowa Utilities Board
AEFAlliant Energy Finance, LLCIUBMDAIowa Utilities Board
AFUDCAllowance for funds used during constructionMarshalltownMarshalltown Generating Station
Alliant EnergyAlliant Energy CorporationMDAManagement’s Discussion and Analysis of Financial Condition and Results of Operations
ATCAFUDCAmerican Transmission CompanyAllowance for funds used during constructionMISOMidcontinent Independent System Operator, Inc.
ATIAlliant EnergyAE Transco Investments, LLCAlliant Energy CorporationMWMegawatt
CDDATCCooling degree daysAmerican Transmission Company LLCMWhMegawatt-hour
ATC HoldingsInterest in American Transmission Company LLC and ATC Holdco LLCN/ANot applicable
Corporate ServicesAlliant Energy Corporate Services, Inc.N/ANote(s)Not applicable
DthDekathermNote(s)Combined Notes to Condensed Consolidated Financial Statements
EGUDthDekathermOPEBOther postretirement benefits
EGUElectric generating unitNOxPPANitrogen oxidePurchased power agreement
EPAU.S. Environmental Protection AgencyOPEBPSCWOther postretirement benefitsPublic Service Commission of Wisconsin
EPSEarnings per weighted average common sharePSCWSECPublic ServiceSecurities and Exchange Commission of Wisconsin
FERCFederal Energy Regulatory CommissionRiversideRiverside Energy Center
Financial StatementsCondensed Consolidated Financial StatementsRMTU.S.RMT, Inc.United States of America
FTRFinancial transmission rightSCRWest RiversideSelective catalytic reductionWest Riverside Energy Center and Solar Facility
Fuel-relatedGAAPElectric production fuel and purchased powerSO2Sulfur dioxide
GAAPU.S. generally accepted accounting principlesU.S.United States of America
HDDHeating degree daysWhiting PetroleumWhiting Petroleum Corporation
IPLInterstate Power and Light CompanyWPLWisconsin Power and Light Company


FORWARD-LOOKING STATEMENTS

Statements contained in this report that are not of historical fact are forward-looking statements intended to qualify for the safe harbors from liability established by the Private Securities Litigation Reform Act of 1995. These forward-looking statements can be identified as such because the statements include words such as “may,” “believe,” “expect,” “anticipate,” “plan,” “project,” “will,” “projections,” “estimate,” or other words of similar import. Similarly, statements that describe future financial performance or plans or strategies are forward-looking statements. Such forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from those expressed in, or implied by, such statements. Some, but not all, of the risks and uncertainties of Alliant Energy, IPL and WPL that could materially affect actual results include:

the direct or indirect effects resulting from cyber security incidents or attacks on Alliant Energy’s, IPL’s or WPL’s physical infrastructure, or responses to such incidents;
federal and state regulatory or governmental actions, including the impact of energy, tax (including potential tax reform), financial and health care legislation, and regulatory agency orders;
IPL’s and WPL’s ability to obtain adequate and timely rate relief to allow for, among other things, earning a return on rate base additions and the recovery of costs, including fuel costs, operating costs, transmission costs, environmental compliance and remediation costs, deferred expenditures, deferred tax assets, capital expenditures, and remaining costs related to EGUs that may be permanently closed, earning their authorized rates of return, and the payments to their parent of expected levels of dividends;
the ability to continue cost controls and operational efficiencies;
the impact of IPL’s pending retail electric base rate review;
weather effects on results of utility operations;
the impact of the economy in IPL’s and WPL’s service territories and the resulting impacts on sales volumes, margins and the ability to collect unpaid bills;
the impact of customer- and third party-owned generation, including alternative electric suppliers, in IPL’s and WPL’s service territories on system reliability, operating expenses and customers’ demand for electricity;
the impact of energy efficiency, franchise retention and customer disconnects on sales volumes and margins;
the impact that price changes may have on IPL’s and WPL’s customers’ demand for electric, gas and steam services and their ability to pay their bills;
developmentsinflation and higher interest rates;
changes in the price of delivered natural gas, transmission, purchased electricity and delivered coal, particularly during elevated market prices, and any resulting changes to counterparty credit risk, due to shifts in supply and demand caused by market conditions, regulations and MISO’s seasonal resource adequacy process;
IPL’s and WPL’s ability to obtain adequate and timely rate relief to allow for, among other things, the recovery of and/or the return on costs, including fuel costs, operating costs, transmission costs, capacity costs, deferred expenditures, deferred tax assets, tax expense, interest expense, capital expenditures, and remaining costs related to EGUs that adversely impact may be permanently closed and certain other retired assets, decreases in sales volumes, earning their authorized rates of return, and the payments to their parent of expected levels of dividends;
the ability to implement the strategic plan;obtain regulatory approval for construction projects with acceptable conditions;
the ability to qualifycomplete construction of renewable generation and storage projects by planned in-service dates and within the cost targets set by regulators due to cost increases of and access to materials, equipment and commodities, which could result from tariffs, duties or other assessments, such as any additional tariffs resulting from U.S. Department of Commerce investigations into and any decisions made regarding the sourcing of solar project materials and equipment from certain countries, labor issues or supply shortages, the ability to successfully resolve warranty issues or contract disputes, the ability to achieve the expected level of tax benefits based on tax guidelines and project costs, and the ability to efficiently utilize the renewable generation and storage project tax benefits for the full levelbenefit of productioncustomers;
the ability to utilize tax credits on planned new wind farmsgenerated to date, and those that may be generated in the future, before they expire, as well as the ability to transfer tax credits that may be generated in the future at adequate pricing;
disruptions to ongoing operations and the supply of materials, services, equipment and commodities needed to construct solar generation, battery storage and electric and gas distribution projects, which may result from geopolitical issues, supplier manufacturing constraints, labor issues or transportation issues, and thus affect the ability to meet capacity requirements and result in increased capacity expense;
the future development of technologies related to electrification, and the ability to reliably store and manage electricity;
federal and state regulatory or governmental actions, including the impact of legislation, and regulatory agency orders;
the impacts of changes in the tax code, including tax rates, minimum tax rates, and adjustments made to productiondeferred tax credits for existing wind farms;

assets and liabilities;
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employee workforce factors, including the ability to hire and retain employees with specialized skills, impacts from employee retirements, changes in key executives, ability to create desired corporate culture, collective bargaining agreements and negotiations, work stoppages or restructurings;
issues related to the availability and operations of EGUs, including start-up risks, breakdown or failure of equipment, performance below expected or contracted levels of output or efficiency, operator error, employee safety, transmission constraints, compliance with mandatory reliability standards and risks related to recovery of resulting incremental costs through rates;
disruptions in the supply and delivery of natural gas, purchased electricity and coal;
changes to the creditworthiness of, or performance of obligations by, counterparties with which Alliant Energy, IPL and WPL have contractual arrangements, including participants in the priceenergy markets and fuel suppliers and transporters;
the impact of delivered natural gas, purchased electricitypenalties or third-party claims related to, or in connection with, a failure to maintain the security of personally identifiable information, including associated costs to notify affected persons and coal due to shifts in supplymitigate their information security concerns;
impacts that terrorist attacks may have on Alliant Energy’s, IPL’s and demand caused by market conditionsWPL’s operations and regulations;recovery of costs associated with restoration activities or on the operations of Alliant Energy’s investments;
impactsany material post-closing payments related to any past asset divestitures, including the sale of Whiting Petroleum, which could result from, among other things, indemnification agreements, warranties, guarantees or litigation;
weather effects on equity income from unconsolidated investments dueresults of utility operations;
continued access to further potential the capital markets on competitive terms and rates, and the actions of credit rating agencies;
changes to ATC LLC’s authorized return on equity;MISO’s resource adequacy process establishing capacity planning reserve margin and capacity accreditation requirements that may impact how and when new and existing generating facilities, including IPL’s and WPL’s additional solar generation, may be accredited with energy capacity, and may require IPL and WPL to adjust their current resource plans, to add resources to meet the requirements of MISO’s process, or procure capacity in the market whereby such costs might not be recovered in rates;
issues associated with environmental remediation and environmental compliance, including compliance with the Consent Decree between WPL, the EPAall environmental and the Sierra Club, the Consent Decree between IPL, the EPA, the Sierra Club, the State of Iowaemissions permits and Linn County in Iowa, the Coal Combustion Residuals Rule, the Clean Power Plan, future changes in environmental laws and regulations, including changes to the EPA’sCoal Combustion Residuals Rule, Cross-State Air Pollution Rule emissions allowances and federal, state or local regulations for carbon dioxidegreenhouse gases emissions reductions from new and existing fossil-fueled EGUs under the Clean Air Act, and litigation associated with environmental requirements;
increased pressure from customers, investors and other stakeholders to more rapidly reduce greenhouse gases emissions;
the ability to defend against environmental claims brought by state and federal agencies, such as the EPA, state natural resources agencies or third parties, such as the Sierra Club, and the impact on operating expenses of defending and resolving such claims;
impacts that storms or natural disasters in IPL’s and WPL’s service territories may have on their operations and recovery of costs associated with restoration activities;
the direct or indirect effects resulting from terrorist incidents, including physical attacks and cyber attacks, or responses to such incidents;
the impact of penalties or third-party claims related to, or in connection with, a failure to maintain the security of personally identifiable information, including associated costs to notify affected persons and to mitigate their information security concerns;
the direct or indirect effects resulting from breakdown or failure of equipment in the operation of electric and gas distribution systems, such as mechanical problems and explosions or fires, and compliance with electric and gas transmission and distribution safety regulations;regulations, including regulations promulgated by the Pipeline and Hazardous Materials Safety Administration;
issues related to the availability and operations of EGUs, including start-up risks, breakdown or failure of equipment, availability of warranty coverage and successful resolution of warranty issues or contract disputes for equipment breakdowns or failures, performance below expected or contracted levels of output or efficiency, operator error, employee safety, transmission constraints, compliance with mandatory reliability standards and risks related to recovery of resulting incremental operating, fuel-related and capital costs through rates;
impacts that excessive heat, excessive cold, storms or natural disasters may have on Alliant Energy’s, IPL’s and WPL’s operations and construction activities, and recovery of costs associated with restoration activities, or on the operations of Alliant Energy’s investments;
the direct or indirect effects resulting from the ongoing novel coronavirus (COVID-19) pandemic and the spread of variant strains;
Alliant Energy’s ability to sustain its dividend payout ratio goal;
changes to costs of providing benefits and related funding requirements of pension and OPEB plans due to the market value of the assets that fund the plans, economic conditions, financial market performance, interest rates, timing and form of benefits payments, life expectancies and demographics;
material changes in employee-related benefit and compensation costs, including settlement losses related to pension plans;
risks associated with operation and ownership of non-utility holdings;
changes in technology that alter the channels through which customers buy or utilize Alliant Energy’s, IPL’s or WPL’s products and services;
impacts on equity income from unconsolidated investments from changes in valuations of the assets held, as well as potential changes to ATC’s authorized return on equity;
impacts of IPL’s future tax benefits from Iowa rate-making practices, including deductions for repairs expenditures, and allocation of mixed service costs and state depreciation, and recoverability of the associated regulatory assets from customers, when the differences reverse in future periods;
risks associated with non-regulated renewable investments;
any material post-closing adjustments related to any past asset divestitures, including the sales of IPL’s Minnesota electric and natural gas assets, and Whiting Petroleum, which could result from, among other things, warranties, parental guarantees or litigation;
continued access to the capital markets on competitive terms and rates, and the actions of credit rating agencies;
inflation and interest rates;
changes to the creditworthiness of counterparties with which Alliant Energy, IPL and WPL have contractual arrangements, including participants in the energy markets and fuel suppliers and transporters;
current or future litigation, regulatory investigations, proceedings or inquiries;
reputational damage from negative publicity, protests, fines, penalties and other negative consequences resulting in regulatory and/or legal actions;
Alliant Energy’s ability to sustain its dividend payout ratio goal;
employee workforce factors, including changes in key executives, collective bargaining agreements and negotiations, work stoppages or restructurings;
changes in technology that alter the channels through which electric customers buy or utilize electricity;
material changes in employee-related benefit and compensation costs;
the effect of accounting standards issued periodically by standard-setting bodies;
the impact of adjustments made to deferred tax assets and liabilities from state apportionment assumptions;
the ability to utilize tax credits and net operating losses generated to date, and those that may be generated in the future, before they expire;
the ability to successfully complete tax audits and changes in tax accounting methods with no material impact on earnings and cash flows; and
factors listed in MDA and Risk Factors in Item 1A in the 2016 Form 10-K.

other factors listed in MDA and Risk Factors in Item 1A in the 2022 Form 10-K.
Alliant Energy, IPL and WPL each assume no obligation, and disclaim any duty, to update the forward-looking statements in this report, except as required by law.

Available Information. Alliant Energy routinely posts important information on its website and considers the Investors section of its website, www.alliantenergy.com/investors, a channel of distribution for material information. Information contained on Alliant Energy’s website is not incorporated herein.
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PART I. FINANCIAL INFORMATION
ITEM 1. CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)
ALLIANT ENERGY CORPORATION
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)
For the Three MonthsFor the Six Months
Ended June 30,Ended June 30,
2023202220232022
(in millions, except per share amounts)
Revenues:
Electric utility$799$812$1,567$1,586
Gas utility7794353356
Other utility13132523
Non-utility23244547
Total revenues9129431,9902,012
Operating expenses:
Electric production fuel and purchased power166191322359
Electric transmission service138133284271
Cost of gas sold3348215216
Other operation and maintenance163166338320
Depreciation and amortization167166333332
Taxes other than income taxes28275954
Total operating expenses6957311,5511,552
Operating income217212439460
Other (income) and deductions:
Interest expense9678190152
Equity income from unconsolidated investments, net(14)(16)(31)(32)
Allowance for funds used during construction(24)(13)(43)(24)
Other(1)21
Total other (income) and deductions574911897
Income before income taxes160163321363
Income tax expense (benefit)4(2)12
Net income attributable to Alliant Energy common shareowners$160$159$323$351
Weighted average number of common shares outstanding:
Basic251.7250.9251.4250.7
Diluted251.9251.1251.6251.0
Earnings per weighted average common share attributable to Alliant Energy common shareowners (basic and diluted)
$0.64$0.63$1.28$1.40
 For the Three Months For the Nine Months
 Ended September 30, Ended September 30,
 2017 2016 2017 2016
 (in millions, except per share amounts)
Operating revenues:       
Electric utility
$840.6
 
$864.3
 
$2,199.1
 
$2,209.1
Gas utility45.8
 39.5
 262.7
 248.7
Other utility11.2
 9.4
 34.4
 35.0
Non-regulated9.3
 11.4
 29.9
 30.2
Total operating revenues906.9
 924.6
 2,526.1
 2,523.0
Operating expenses:       
Electric production fuel and purchased power222.6
 245.9
 614.7
 646.3
Electric transmission service121.0
 138.6
 363.3
 396.8
Cost of gas sold15.0
 12.5
 135.5
 132.3
Asset valuation charges for Franklin County wind farm
 86.4
 
 86.4
Other operation and maintenance169.1
 148.6
 467.1
 438.2
Depreciation and amortization120.7
 104.1
 342.7
 308.7
Taxes other than income taxes27.0
 25.9
 79.1
 77.2
Total operating expenses675.4
 762.0
 2,002.4
 2,085.9
Operating income231.5
 162.6
 523.7
 437.1
Interest expense and other:       
Interest expense53.9
 48.8
 159.0
 144.8
Equity income from unconsolidated investments, net(10.1) (9.2) (32.9) (28.8)
Allowance for funds used during construction(9.6) (15.8) (36.7) (44.3)
Interest income and other(0.2) (0.1) (0.4) (0.3)
Total interest expense and other34.0
 23.7
 89.0
 71.4
Income from continuing operations before income taxes197.5
 138.9
 434.7
 365.7
Income taxes26.1
 7.5
 64.9
 47.2
Income from continuing operations, net of tax171.4
 131.4
 369.8
 318.5
Income (loss) from discontinued operations, net of tax
 (0.4) 1.4
 (2.0)
Net income171.4
 131.0
 371.2
 316.5
Preferred dividend requirements of Interstate Power and Light Company2.6
 2.6
 7.7
 7.7
Net income attributable to Alliant Energy common shareowners
$168.8
 
$128.4
 
$363.5
 
$308.8
Weighted average number of common shares outstanding (basic and diluted)231.0
 227.2
 229.2
 227.0
Earnings per weighted average common share attributable to Alliant Energy common shareowners (basic and diluted):
       
Income from continuing operations, net of tax
$0.73
 
$0.57
 
$1.58
 
$1.37
Income (loss) from discontinued operations, net of tax
 
 0.01
 (0.01)
Net income
$0.73
 
$0.57
 
$1.59
 
$1.36
Amounts attributable to Alliant Energy common shareowners:       
Income from continuing operations, net of tax
$168.8
 
$128.8
 
$362.1
 
$310.8
Income (loss) from discontinued operations, net of tax
 (0.4) 1.4
 (2.0)
Net income
$168.8
 
$128.4
 
$363.5
 
$308.8
Dividends declared per common share
$0.315
 
$0.29375
 
$0.945
 
$0.88125


TheRefer to accompanying Combined Notes to Condensed Consolidated Financial Statements are an integral part of these statements.

Statements.
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ALLIANT ENERGY CORPORATION
CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)
June 30,
2023
December 31,
2022
(in millions, except per
share and share amounts)
ASSETS
Current assets:
Cash and cash equivalents$13$20
Accounts receivable, less allowance for expected credit losses428516
Production fuel, at weighted average cost6453
Gas stored underground, at weighted average cost69132
Materials and supplies, at weighted average cost172140
Regulatory assets196166
Other196223
Total current assets1,1381,250
Property, plant and equipment, net16,30616,247
Investments:
ATC Holdings372358
Other212201
Total investments584559
Other assets:
Regulatory assets2,1481,880
Deferred charges and other207227
Total other assets2,3552,107
Total assets$20,383$20,163
 September 30,
2017
 December 31,
2016
 
(in millions, except per
share and share amounts)
ASSETS   
Current assets:   
Cash and cash equivalents
$9.2
 
$8.2
Accounts receivable, less allowance for doubtful accounts336.1
 493.3
Production fuel, at weighted average cost80.9
 98.1
Gas stored underground, at weighted average cost40.6
 37.6
Materials and supplies, at weighted average cost99.1
 86.6
Regulatory assets84.2
 57.8
Other101.4
 95.5
Total current assets751.5
 877.1
Property, plant and equipment, net10,931.1
 10,279.2
Investments:   
ATC Investment339.2
 317.6
Other119.4
 20.0
Total investments458.6
 337.6
Other assets:   
Regulatory assets1,952.3
 1,857.3
Deferred charges and other21.4
 22.6
Total other assets1,973.7
 1,879.9
Total assets
$14,114.9
 
$13,373.8
LIABILITIES AND EQUITY
Current liabilities:
Current maturities of long-term debt$409$408
Commercial paper391642
Other short-term borrowings50
Accounts payable585756
Regulatory liabilities121206
Other337351
Total current liabilities1,8932,363
Long-term debt, net (excluding current portion)8,1867,668
Other liabilities:
Deferred tax liabilities1,9691,943
Regulatory liabilities1,0871,118
Pension and other benefit obligations262277
Other534518
Total other liabilities3,8523,856
Commitments and contingencies (Note 13)
Equity:
Alliant Energy Corporation common equity:
Common stock - $0.01 par value - 480,000,000 shares authorized; 252,719,092 and 251,134,966 shares outstanding33
Additional paid-in capital2,8542,777
Retained earnings3,6063,509
Accumulated other comprehensive income3
Shares in deferred compensation trust - 405,051 and 402,134 shares at a weighted average cost of $33.69 and $32.63 per share(14)(13)
Total Alliant Energy Corporation common equity6,4526,276
Total liabilities and equity$20,383$20,163

LIABILITIES AND EQUITY   
Current liabilities:   
Current maturities of long-term debt
$105.2
 
$4.6
Commercial paper390.3
 244.1
Other short-term borrowings95.0
 
Accounts payable478.1
 445.3
Regulatory liabilities145.1
 186.2
Accrued taxes39.4
 59.5
Other217.0
 222.3
Total current liabilities1,470.1
 1,162.0
Long-term debt, net (excluding current portion)4,255.1
 4,315.6
Other liabilities:   
Deferred tax liabilities2,774.7
 2,570.2
Regulatory liabilities483.4
 494.8
Pension and other benefit obligations481.3
 489.9
Other296.1
 279.3
Total other liabilities4,035.5
 3,834.2
Commitments and contingencies (Note 12)


 

Equity:   
Alliant Energy Corporation common equity:   
Common stock - $0.01 par value - 480,000,000 shares authorized; 231,204,360 and 227,673,654 shares outstanding2.3
 2.3
Additional paid-in capital1,838.2
 1,693.1
Retained earnings2,324.8
 2,177.0
Accumulated other comprehensive loss(0.4) (0.4)
Shares in deferred compensation trust - 454,532 and 441,695 shares at a weighted average cost of $23.52 and $22.71 per share(10.7) (10.0)
Total Alliant Energy Corporation common equity4,154.2
 3,862.0
Cumulative preferred stock of Interstate Power and Light Company200.0
 200.0
Total equity4,354.2
 4,062.0
Total liabilities and equity
$14,114.9
 
$13,373.8

TheRefer to accompanying Combined Notes to Condensed Consolidated Financial Statements are an integral part of these statements.

Statements.
4

Table of Contents


ALLIANT ENERGY CORPORATION
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)
For the Six Months
Ended June 30,
20232022
(in millions)
Cash flows from operating activities:
Net income$323$351
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization333332
Equity component of allowance for funds used during construction(32)(18)
Other1414
Other changes in assets and liabilities:
Accounts receivable(186)(283)
Gas stored underground6317
Derivative assets86(183)
Regulatory assets(36)(116)
Accounts payable(84)95
Derivative liabilities1886
Regulatory liabilities(116)74
Deferred income taxes2434
Other(96)(103)
Net cash flows from operating activities311300
Cash flows used for investing activities:
Construction and acquisition expenditures:
Utility business(758)(550)
Other(62)(43)
Cash receipts on sold receivables272233
Proceeds from sales of partial ownership interest in West Riverside120
Other(54)(10)
Net cash flows used for investing activities(482)(370)
Cash flows from financing activities:
Common stock dividends(226)(215)
Proceeds from issuance of common stock, net7613
Proceeds from issuance of long-term debt862650
Payments to retire long-term debt(404)(304)
Net change in commercial paper and other short-term borrowings(146)(116)
Contributions from noncontrolling interest29
Other(1)(7)
Net cash flows from financing activities16150
Net decrease in cash, cash equivalents and restricted cash(10)(20)
Cash, cash equivalents and restricted cash at beginning of period2440
Cash, cash equivalents and restricted cash at end of period$14$20
Supplemental cash flows information:
Cash (paid) refunded during the period for:
Interest($179)($146)
Income taxes, net$3($4)
Significant non-cash investing and financing activities:
Accrued capital expenditures$300$200
Beneficial interest obtained in exchange for securitized accounts receivable$175$244
 For the Nine Months
 Ended September 30,
 2017 2016
 (in millions)
Cash flows from operating activities:   
Net income
$371.2
 
$316.5
Adjustments to reconcile net income to net cash flows from operating activities:   
Depreciation and amortization342.7
 308.7
Deferred tax expense and tax credits102.7
 76.7
Asset valuation charges for Franklin County wind farm
 86.4
Other(7.1) (44.0)
Other changes in assets and liabilities:   
Accounts receivable72.8
 (101.0)
Sales of accounts receivable91.0
 (4.0)
Regulatory assets(108.9) 36.6
Regulatory liabilities(64.8) (66.5)
Deferred income taxes101.0
 71.8
Other(17.2) (27.2)
Net cash flows from operating activities883.4
 654.0
Cash flows used for investing activities:   
Construction and acquisition expenditures:   
Utility business(909.7) (743.6)
Alliant Energy Corporate Services, Inc. and non-regulated businesses(139.7) (43.3)
Other(22.9) 15.1
Net cash flows used for investing activities(1,072.3) (771.8)
Cash flows from financing activities:   
Common stock dividends(215.7) (199.8)
Proceeds from issuance of common stock, net143.2
 20.4
Proceeds from issuance of long-term debt
 300.0
Net change in commercial paper and other short-term borrowings281.2
 78.5
Other(18.8) (2.4)
Net cash flows from financing activities189.9
 196.7
Net increase in cash and cash equivalents1.0
 78.9
Cash and cash equivalents at beginning of period8.2
 5.8
Cash and cash equivalents at end of period
$9.2
 
$84.7
Supplemental cash flows information:   
Cash paid during the period for:   
Interest, net of capitalized interest
($158.5) 
($140.7)
Income taxes, net
($11.4) 
($8.3)
Significant non-cash investing and financing activities:   
Accrued capital expenditures
$197.2
 
$99.9


TheRefer to accompanying Combined Notes to Condensed Consolidated Financial Statements are an integral part of these statements.

Statements.
5

Table of Contents


INTERSTATE POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)
For the Three MonthsFor the Six Months
For the Three Months For the Nine MonthsEnded June 30,Ended June 30,
Ended September 30, Ended September 30,2023202220232022
2017 2016 2017 2016(in millions)
(in millions)
Operating revenues:       
Revenues:Revenues:
Electric utility
$489.0
 
$483.2
 
$1,217.6
 
$1,209.2
Electric utility$431$442$819$843
Gas utility27.4
 23.9
 147.2
 142.6
Gas utility4452194191
Steam and other11.0
 9.1
 33.3
 34.1
Steam and other12122422
Total operating revenues527.4
 516.2
 1,398.1
 1,385.9
Total revenuesTotal revenues4875061,0371,056
Operating expenses:       Operating expenses:
Electric production fuel and purchased power122.5
 125.0
 330.0
 324.8
Electric production fuel and purchased power6683113150
Electric transmission service78.2
 95.9
 235.0
 270.7
Electric transmission service9691201188
Cost of gas sold9.9
 8.0
 74.6
 76.3
Cost of gas sold2027116112
Other operation and maintenance104.4
 94.8
 288.7
 279.8
Other operation and maintenance8587181171
Depreciation and amortization66.2
 52.7
 181.0
 157.8
Depreciation and amortization9695191189
Taxes other than income taxes14.4
 13.9
 41.1
 40.6
Taxes other than income taxes14142928
Total operating expenses395.6
 390.3
 1,150.4
 1,150.0
Total operating expenses377397831838
Operating income131.8
 125.9
 247.7
 235.9
Operating income110109206218
Interest expense and other:       
Other (income) and deductions:Other (income) and deductions:
Interest expense27.9
 25.5
 83.5
 75.4
Interest expense37377474
Allowance for funds used during construction(4.7) (13.8) (25.1) (36.2)Allowance for funds used during construction(4)(3)(8)(5)
Interest income and other(0.1) 
 (0.2) (0.1)
Total interest expense and other23.1
 11.7
 58.2
 39.1
OtherOther13(1)
Total other (income) and deductionsTotal other (income) and deductions34346968
Income before income taxes108.7
 114.2
 189.5
 196.8
Income before income taxes7675137150
Income tax benefit(14.3) (2.5) (18.6) (2.5)Income tax benefit(13)(12)(24)(23)
Net income123.0
 116.7
 208.1
 199.3
Net income$89$87$161$173
Preferred dividend requirements2.6
 2.6
 7.7
 7.7
Earnings available for common stock
$120.4
 
$114.1
 
$200.4
 
$191.6
Earnings per share data is not disclosed given Alliant Energy Corporation is the sole shareowner of all shares of IPL’s common stock outstanding during the periods presented.
TheRefer to accompanying Combined Notes to Condensed Consolidated Financial Statements are an integral part of these statements.

Statements.
6

Table of Contents


INTERSTATE POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)
June 30,
2023
December 31,
2022
(in millions, except per
share and share amounts)
ASSETS
Current assets:
Cash and cash equivalents$9$15
Accounts receivable, less allowance for expected credit losses204259
Production fuel, at weighted average cost3123
Gas stored underground, at weighted average cost2760
Materials and supplies, at weighted average cost10083
Regulatory assets9085
Other7893
Total current assets539618
Property, plant and equipment, net7,9238,046
Other assets:
Regulatory assets1,5581,301
Deferred charges and other101110
Total other assets1,6591,411
Total assets$10,121$10,075
 September 30,
2017
 December 31,
2016
 
(in millions, except per
share and share amounts)
ASSETS 
Current assets:   
Cash and cash equivalents
$4.7
 
$3.3
Accounts receivable, less allowance for doubtful accounts143.5
 240.7
Production fuel, at weighted average cost56.7
 70.3
Gas stored underground, at weighted average cost21.6
 16.3
Materials and supplies, at weighted average cost52.6
 46.5
Regulatory assets38.9
 17.7
Other39.3
 27.7
Total current assets357.3
 422.5
Property, plant and equipment, net5,764.9
 5,435.6
Other assets:   
Regulatory assets1,552.0
 1,441.1
Deferred charges and other8.5
 5.5
Total other assets1,560.5
 1,446.6
Total assets
$7,682.7
 
$7,304.7
LIABILITIES AND EQUITY
Current liabilities:
Accounts payable$247$239
Accounts payable to associated companies4028
Accrued taxes5152
Accrued interest3535
Regulatory liabilities73114
Other97113
Total current liabilities543581
Long-term debt, net3,7023,646
Other liabilities:
Deferred tax liabilities1,0611,047
Regulatory liabilities603640
Pension and other benefit obligations6062
Other283291
Total other liabilities2,0072,040
Commitments and contingencies (Note 13)
Equity:
Interstate Power and Light Company common equity:
Common stock - $2.50 par value - 24,000,000 shares authorized; 13,370,788 shares outstanding3333
Additional paid-in capital2,8472,807
Retained earnings989968
Total Interstate Power and Light Company common equity3,8693,808
Total liabilities and equity$10,121$10,075

LIABILITIES AND EQUITY 
Current liabilities:   
Current maturities of long-term debt
$100.0
 
$—
Commercial paper4.0
 
Accounts payable224.6
 186.3
Accounts payable to associated companies56.4
 43.3
Regulatory liabilities85.9
 149.6
Accrued taxes39.3
 53.8
Other92.8
 88.8
Total current liabilities603.0
 521.8
Long-term debt, net (excluding current portion)2,095.0
 2,153.5
Other liabilities:   
Deferred tax liabilities1,643.5
 1,511.8
Regulatory liabilities298.9
 281.2
Pension and other benefit obligations171.4
 173.2
Other238.5
 214.2
Total other liabilities2,352.3
 2,180.4
Commitments and contingencies (Note 12)


 

Equity:   
Interstate Power and Light Company common equity:   
Common stock - $2.50 par value - 24,000,000 shares authorized; 13,370,788 shares outstanding33.4
 33.4
Additional paid-in capital1,697.8
 1,597.8
Retained earnings701.2
 617.8
Total Interstate Power and Light Company common equity2,432.4
 2,249.0
Cumulative preferred stock200.0
 200.0
Total equity2,632.4
 2,449.0
Total liabilities and equity
$7,682.7
 
$7,304.7

TheRefer to accompanying Combined Notes to Condensed Consolidated Financial Statements are anintegral part of these statements.

Statements.
7

Table of Contents


INTERSTATE POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)
For the Six Months
Ended June 30,
20232022
(in millions)
Cash flows from operating activities:
Net income$161$173
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization191189
Other2(9)
Other changes in assets and liabilities:
Accounts receivable(216)(256)
Gas stored underground3312
Derivative assets43(123)
Regulatory assets(2)(52)
Accounts payable(32)67
Derivative liabilities(9)63
Regulatory liabilities(78)53
Deferred income taxes824
Other(49)(58)
Net cash flows from operating activities5283
Cash flows from (used for) investing activities:
Construction and acquisition expenditures(251)(172)
Cash receipts on sold receivables272233
Other(36)(1)
Net cash flows from (used for) investing activities(15)60
Cash flows used for financing activities:
Common stock dividends(140)(160)
Capital contributions from parent40
Net change in commercial paper55
Other2(4)
Net cash flows used for financing activities(43)(164)
Net decrease in cash, cash equivalents and restricted cash(6)(21)
Cash, cash equivalents and restricted cash at beginning of period1534
Cash, cash equivalents and restricted cash at end of period$9$13
Supplemental cash flows information:
Cash (paid) refunded during the period for:
Interest($74)($74)
Income taxes, net$25$19
Significant non-cash investing and financing activities:
Accrued capital expenditures$95$45
Beneficial interest obtained in exchange for securitized accounts receivable$175$244
 For the Nine Months
 Ended September 30,
 2017 2016
 (in millions)
Cash flows from operating activities:   
Net income
$208.1
 
$199.3
Adjustments to reconcile net income to net cash flows from operating activities:   
Depreciation and amortization181.0
 157.8
Other26.2
 24.3
Other changes in assets and liabilities:   
Accounts receivable12.4
 (66.5)
Sales of accounts receivable91.0
 (4.0)
Regulatory assets(107.8) (14.1)
Regulatory liabilities(49.6) (64.5)
Deferred income taxes88.9
 67.7
Other20.4
 (43.5)
Net cash flows from operating activities470.6
 256.5
Cash flows used for investing activities:   
Utility construction and acquisition expenditures(470.1) (436.5)
Other(23.5) 1.1
Net cash flows used for investing activities(493.6) (435.4)
Cash flows from financing activities:   
Common stock dividends(117.0) (114.0)
Capital contributions from parent100.0
 65.0
Proceeds from issuance of long-term debt
 300.0
Net change in commercial paper44.0
 
Other(2.6) 1.1
Net cash flows from financing activities24.4
 252.1
Net increase in cash and cash equivalents1.4
 73.2
Cash and cash equivalents at beginning of period3.3
 4.5
Cash and cash equivalents at end of period
$4.7
 
$77.7
Supplemental cash flows information:   
Cash (paid) refunded during the period for:   
Interest
($84.1) 
($72.5)
Income taxes, net
$13.2
 
$0.7
Significant non-cash investing and financing activities:   
Accrued capital expenditures
$71.0
 
$44.5


TheRefer to accompanying Combined Notes to Condensed Consolidated Financial Statements are an integral part of these statements.



Statements.
8

Table of Contents


WISCONSIN POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)
For the Three MonthsFor the Six Months
For the Three Months For the Nine MonthsEnded June 30,Ended June 30,
Ended September 30, Ended September 30,2023202220232022
2017 2016 2017 2016(in millions)
(in millions)
Operating revenues:       
Revenues:Revenues:
Electric utility
$351.6
 
$381.1
 
$981.5
 
$999.9
Electric utility$368$370$748$743
Gas utility18.4
 15.6
 115.5
 106.1
Gas utility3342159165
Other0.2
 0.3
 1.1
 0.9
Other1111
Total operating revenues370.2
 397.0
 1,098.1
 1,106.9
Total revenuesTotal revenues402413908909
Operating expenses:       Operating expenses:
Electric production fuel and purchased power100.1
 120.9
 284.7
 321.5
Electric production fuel and purchased power99108209209
Electric transmission service42.8
 42.7
 128.3
 126.1
Electric transmission service42418383
Cost of gas sold5.1
 4.5
 60.9
 56.0
Cost of gas sold132199104
Other operation and maintenance66.1
 54.2
 179.7
 157.2
Other operation and maintenance6767133123
Depreciation and amortization53.6
 48.7
 158.8
 143.5
Depreciation and amortization6969137139
Taxes other than income taxes11.8
 11.0
 35.3
 33.8
Taxes other than income taxes13122724
Total operating expenses279.5
 282.0
 847.7
 838.1
Total operating expenses303318688682
Operating income90.7
 115.0
 250.4
 268.8
Operating income9995220227
Interest expense and other:       
Other (income) and deductions:Other (income) and deductions:
Interest expense23.1
 22.9
 69.1
 68.7
Interest expense36287255
Equity income from unconsolidated investments(0.2) (9.3) (0.4) (29.0)
Allowance for funds used during construction(4.9) (2.0) (11.6) (8.1)Allowance for funds used during construction(19)(10)(35)(18)
Interest income and other(0.1) 0.1
 (0.2) (0.2)
Total interest expense and other17.9
 11.7
 56.9
 31.4
OtherOther(4)(3)
Total other (income) and deductionsTotal other (income) and deductions13183437
Income before income taxes72.8
 103.3
 193.5
 237.4
Income before income taxes8677186190
Income taxes23.0
 33.7
 60.1
 77.1
Income tax expenseIncome tax expense14142634
Net income49.8
 69.6
 133.4
 160.3
Net income$72$63$160$156
Net income attributable to noncontrolling interest
 0.6
 
 1.6
Earnings available for common stock
$49.8
 
$69.0
 
$133.4
 
$158.7
Earnings per share data is not disclosed given Alliant Energy Corporation is the sole shareowner of all shares of WPL’s common stock outstanding during the periods presented.
TheRefer to accompanying Combined Notes to Condensed Consolidated Financial Statements are an integral part of these statements.

Statements.
9

Table of Contents


WISCONSIN POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)
 September 30,
2017
 December 31,
2016
 
(in millions, except per
share and share amounts)
ASSETS 
Current assets:   
Cash and cash equivalents
$3.2
 
$4.2
Accounts receivable, less allowance for doubtful accounts185.8
 226.3
Production fuel, at weighted average cost24.2
 27.8
Gas stored underground, at weighted average cost19.0
 21.3
Materials and supplies, at weighted average cost43.6
 36.3
Regulatory assets45.3
 40.1
Other64.6
 60.5
Total current assets385.7
 416.5
Property, plant and equipment, net4,782.4
 4,426.7
Other assets:   
Regulatory assets400.3
 416.2
Deferred charges and other25.7
 30.9
Total other assets426.0
 447.1
Total assets
$5,594.1
 
$5,290.3
June 30,
2023
December 31,
2022
(in millions, except per
share and share amounts)
ASSETS
Current assets:
Cash and cash equivalents$3$5
Accounts receivable, less allowance for expected credit losses210244
Production fuel, at weighted average cost3329
Gas stored underground, at weighted average cost4273
Materials and supplies, at weighted average cost7054
Regulatory assets10681
Prepaid gross receipts tax4742
Other4760
Total current assets558588
Property, plant and equipment, net7,8827,722
Other assets:
Regulatory assets590579
Deferred charges and other6998
Total other assets659677
Total assets$9,099$8,987
LIABILITIES AND EQUITY
Current liabilities:
Commercial paper$44$290
Accounts payable277456
Regulatory liabilities4892
Other140111
Total current liabilities509949
Long-term debt, net3,0682,770
Other liabilities:
Deferred tax liabilities785789
Regulatory liabilities484478
Pension and other benefit obligations127140
Other387370
Total other liabilities1,7831,777
Commitments and contingencies (Note 13)
Equity:
Wisconsin Power and Light Company common equity:
Common stock - $5 par value - 18,000,000 shares authorized; 13,236,601 shares outstanding6666
Additional paid-in capital2,4132,233
Retained earnings1,2601,192
Total Wisconsin Power and Light Company common equity3,7393,491
Total liabilities and equity$9,099$8,987
LIABILITIES AND EQUITY 
Current liabilities:   
Commercial paper
$224.6
 
$52.3
Accounts payable197.2
 192.9
Regulatory liabilities59.2
 36.6
Other108.7
 112.9
Total current liabilities589.7
 394.7
Long-term debt, net1,536.2
 1,535.2
Other liabilities:   
Deferred tax liabilities1,035.2
 971.6
Regulatory liabilities184.5
 213.6
Capital lease obligations - Sheboygan Falls Energy Facility72.0
 77.2
Pension and other benefit obligations204.2
 207.8
Other162.6
 159.4
Total other liabilities1,658.5
 1,629.6
Commitments and contingencies (Note 12)

 
Equity:   
Wisconsin Power and Light Company common equity:   
Common stock - $5 par value - 18,000,000 shares authorized; 13,236,601 shares outstanding66.2
 66.2
Additional paid-in capital1,059.0
 1,019.0
Retained earnings684.5
 645.6
Total Wisconsin Power and Light Company common equity1,809.7
 1,730.8
Total liabilities and equity
$5,594.1
 
$5,290.3


TheRefer to accompanying Combined Notes to Condensed Consolidated Financial Statements are an integral part of these statements.

Statements.
10

Table of Contents


WISCONSIN POWER AND LIGHT COMPANY
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)
For the Six Months
Ended June 30,
20232022
(in millions)
Cash flows from operating activities:
Net income$160$156
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization137139
Equity component of allowance for funds used during construction(26)(14)
Other(4)18
Other changes in assets and liabilities:
Accounts receivable33(17)
Gas stored underground315
Derivative assets47(60)
Regulatory assets(35)(65)
Accounts payable(54)38
Derivative liabilities2723
Regulatory liabilities(38)20
Other(10)(45)
Net cash flows from operating activities268198
Cash flows used for investing activities:
Construction and acquisition expenditures(507)(378)
Proceeds from sales of partial ownership interest in West Riverside120
Other(15)(6)
Net cash flows used for investing activities(402)(384)
Cash flows from financing activities:
Common stock dividends(92)(89)
Capital contributions from parent180265
Proceeds from issuance of long-term debt297
Net change in commercial paper(246)(14)
Contributions from noncontrolling interest29
Other(7)(3)
Net cash flows from financing activities132188
Net increase (decrease) in cash, cash equivalents and restricted cash(2)2
Cash, cash equivalents and restricted cash at beginning of period52
Cash, cash equivalents and restricted cash at end of period$3$4
Supplemental cash flows information:
Cash paid during the period for:
Interest($69)($54)
Income taxes, net($42)($31)
Significant non-cash investing and financing activities:
Accrued capital expenditures$196$150
 For the Nine Months
 Ended September 30,
 2017 2016
 (in millions)
Cash flows from operating activities:   
Net income
$133.4
 
$160.3
Adjustments to reconcile net income to net cash flows from operating activities:   
Depreciation and amortization158.8
 143.5
Deferred tax expense and tax credits60.1
 97.9
Other4.8
 (20.3)
Other changes in assets and liabilities:   
Accounts receivable41.8
 (12.8)
Regulatory assets(1.1) 50.7
Other(36.6) 20.0
Net cash flows from operating activities361.2
 439.3
Cash flows used for investing activities:   
Utility construction and acquisition expenditures(454.0) (307.1)
Other(16.2) (19.6)
Net cash flows used for investing activities(470.2) (326.7)
Cash flows from (used for) financing activities:   
Common stock dividends(94.5) (101.2)
Capital contribution from parent40.0
 
Net change in commercial paper172.3
 (8.1)
Other(9.8) 1.9
Net cash flows from (used for) financing activities108.0
 (107.4)
Net increase (decrease) in cash and cash equivalents(1.0) 5.2
Cash and cash equivalents at beginning of period4.2
 0.4
Cash and cash equivalents at end of period
$3.2
 
$5.6
Supplemental cash flows information:   
Cash (paid) refunded during the period for:   
Interest
($68.1) 
($67.7)
Income taxes, net
($20.2) 
$19.6
Significant non-cash investing and financing activities:   
Accrued capital expenditures
$122.3
 
$50.8


TheRefer to accompanying Combined Notes to Condensed Consolidated Financial Statements are an integral part of these statements.

Statements.
11

Table of Contents


ALLIANT ENERGY CORPORATION
INTERSTATE POWER AND LIGHT COMPANY
WISCONSIN POWER AND LIGHT COMPANY


COMBINED NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)


NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
NOTE 1(a) General - The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission.SEC. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the latest combined Annual Report on 2022 Form 10-K.10-K.


In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the ninesix months ended SeptemberJune 30, 20172023 are not necessarily indicative of results that may be expected for the year ending December 31, 2017. 2023.

A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred. Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes.


Discontinued operations reported in Alliant Energy’s income statements is related to various warranty claims associated with the sale of RMT in 2013, which have resulted in operating expenses and income subsequent to the sale.

NOTE 1(b) New Accounting Standards -
Revenue Recognition - In May 2014, the Financial Accounting Standards Board issued an accounting standard providing principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. This standard also requires disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018 and currently expect to use the modified retrospective method of adoption. If applicable, this method requires a cumulative-effect adjustment to the opening retained earnings balance on January 1, 2018, as if the standard had always been in effect. Alliant Energy, IPL and WPL have continued to make progress in the evaluation of the revenue recognition standard and do not currently anticipate a significant change in revenue recognition for retail electric and gas sales. These sales represent the majority of Alliant Energy’s, IPL’s and WPL’s revenues and are from tariff offerings that provide electricity or natural gas without a defined contractual term. For such arrangements, revenues from contracts with customers will be equivalent to the electricity or natural gas supplied and billed, or estimated to be billed, and there will be no significant shift in the timing or pattern of revenue recognition for such sales. The most significant impact to the financial statements for Alliant Energy, IPL and WPL is expected to be in the form of additional disclosures. The incremental disclosures could include disaggregation of revenue by location and customer class. Alliant Energy, IPL and WPL expect to complete the evaluation of the impact of the revenue recognition standard on their financial condition, results of operations and disclosures by January 1, 2018.

Leases - In February 2016, the Financial Accounting Standards Board issued an accounting standard requiring lease assets and lease liabilities, including operating leases, to be recognized on the balance sheet for all leases with terms longer than 12 months. The standard also requires disclosure of key information about leasing arrangements. Alliant Energy, IPL and WPL currently expect to adopt this standard on January 1, 2019 and are evaluating the impact of this standard on their financial condition and results of operations and expect an increase in assets and liabilities from recognizing operating leases on their balance sheets.

Presentation of Net Periodic Pension and Postretirement Benefit Costs - In March 2017, the Financial Accounting Standards Board issued an accounting standard amending the income statement presentation of the components of net periodic benefit costs for defined benefit pension and other postretirement plans. The standard requires entities to (1) disaggregate the current service cost component from the other components of net periodic benefit costs and present it with other employee compensation costs in the income statement; and (2) include the other components in the income statement outside of operating income. This new presentation will shift the majority of the net periodic benefit costs from “Other operation and maintenance” expenses to “Interest expense and other” expenses in the income statements. In addition, only the service cost component of net periodic benefit costs is eligible for capitalization into property, plant and equipment, when

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applicable. IPL and WPL, as rate-regulated entities, currently expect to capitalize the other components of net periodic benefit costs into regulatory assets or regulatory liabilities. Alliant Energy, IPL and WPL will adopt this standard on January 1, 2018. Upon adoption, the standard must be applied retrospectively for the presentation requirements and prospectively for the capitalization requirements. Alliant Energy, IPL and WPL continue to evaluate additional impacts of this standard on their financial condition and results of operations.

NOTE 2. REGULATORY MATTERS
Regulatory Assets and Regulatory Liabilities -
Regulatory assets were comprised of the following items (in millions):
Alliant EnergyIPLWPL
June 30,
2023
December 31,
2022
June 30,
2023
December 31,
2022
June 30,
2023
December 31,
2022
Tax-related$957$929$868$848$89$81
Pension and OPEB costs378392190197188195
Assets retired early29070274531617
Asset retirement obligations1971511561104141
Commodity cost recovery14516061139159
Derivatives1028441486136
IPL’s Duane Arnold Energy Center PPA amendment54665466
WPL’s Western Wisconsin gas distribution expansion investments47484748
Other174146596311583
$2,344$2,046$1,648$1,386$696$660
 Alliant Energy IPL WPL
 September 30,
2017
 December 31,
2016
 September 30,
2017
 December 31,
2016
 September 30,
2017
 December 31,
2016
Tax-related
$1,147.9
 
$1,055.6
 
$1,107.9
 
$1,022.4
 
$40.0
 
$33.2
Pension and OPEB costs547.8
 578.7
 279.3
 294.0
 268.5
 284.7
Asset retirement obligations107.9
 105.9
 71.9
 64.3
 36.0
 41.6
EGUs retired early67.4
 41.4
 32.9
 
 34.5
 41.4
Derivatives49.9
 30.7
 22.3
 10.0
 27.6
 20.7
Emission allowances25.6
 26.2
 25.6
 26.2
 
 
Other90.0
 76.6
 51.0
 41.9
 39.0
 34.7
 
$2,036.5
 
$1,915.1
 
$1,590.9
 
$1,458.8
 
$445.6
 
$456.3


Regulatory liabilities were comprised of the following items (in millions):
 Alliant Energy IPL WPL
 September 30,
2017
 December 31,
2016
 September 30,
2017
 December 31,
2016
 September 30,
2017
 December 31,
2016
Cost of removal obligations
$412.1
 
$411.6
 
$272.9
 
$269.4
 
$139.2
 
$142.2
Electric transmission cost recovery94.8
 72.0
 35.9
 35.7
 58.9
 36.3
IPL’s tax benefit riders45.0
 83.5
 45.0
 83.5
 
 
Commodity cost recovery21.2
 30.8
 15.0
 17.8
 6.2
 13.0
Energy efficiency cost recovery20.0
 20.5
 
 
 20.0
 20.5
Derivatives10.9
 31.5
 5.8
 12.1
 5.1
 19.4
Other24.5
 31.1
 10.2
 12.3
 14.3
 18.8
 
$628.5
 
$681.0
 
$384.8
 
$430.8
 
$243.7
 
$250.2

Tax-related- Alliant Energy’s and IPL’s tax-related regulatory assets are generally impacted by certain property-related differences at IPL for which deferred tax is not recorded in the income statement pursuant to Iowa rate-making principles. Deferred tax amounts for such property-related differences at IPL are recorded to regulatory assets, along with the necessary revenue requirement tax gross-ups. During the nine months ended September 30, 2017, Alliant Energy’s and IPL’s tax-related regulatory assets increased primarily due to property-related differences for qualifying repair expenditures.

Asset retirement obligations - In September 2017, IPL reached a partial settlement agreement related to its retail electric rate review (2016 Test Year), subject to IUB approval. The proposed settlement does not include the recovery of certain asset retirement obligation costs previously recorded as regulatory assets, and as a result, Alliant Energy and IPL recorded a write-down of regulatory assets in the third quarter of 2017 as discussed in “IPL’s Retail Electric Rate Review (2016 Test Year)” below.

Electric generating unitsAssets retired early - In June 2017,May 2023, IPL retired Sutherland Units 1 and 3the coal-fired Lansing Generating Station and reclassified the remaining net book value of these EGUsthis EGU from property, plant and equipment to a regulatory asset on Alliant Energy’s and IPL’s balance sheets. The related regulatory asset balance as of June 30, 2023 was $226 million, which is currently included in IPL’s rate base and IPL is currently earning a return of and a return on the remaining net book value of these EGUs, as well as recovering the remaining net book value of these EGUs from both its retail and wholesale customers. IPL’s proposed settlement reached in September 2017 includesbalance. Continued recovery of the remaining net book value of these EGUs fromLansing is expected to be addressed in future IPL rate reviews.

Derivatives - Refer to Note 11 for discussion of changes in Alliant Energy’s, IPL’s retail customers over a 10-year period. However,and WPL’s derivative liabilities/assets during the proposed settlement does not allow IPLsix months ended June 30, 2023, which resulted in comparable changes to earn a returnregulatory assets/liabilities on the remaining net book value of these EGUs from its retail customers when final rates are implemented, and as a result, Alliant Energy and IPL recorded a write-down of regulatory assets in the third quarter of 2017 as discussed in “IPL’s Retail Electric Rate Review (2016 Test Year)” below. IPL has requested continued recoverybalance sheets.

Regulatory liabilities were comprised of the remaining net book value of these EGUs from its retail customers over a 10-year period from the IUB, with a decision currently expected in the first quarter of 2018. In September 2017, FERC approved continued recovery of the remaining net book value of these EGUs from IPL’s wholesale customers over a 10-year period.following items (in millions):

Alliant EnergyIPLWPL
June 30,
2023
December 31,
2022
June 30,
2023
December 31,
2022
June 30,
2023
December 31,
2022
Tax-related$572$579$301$303$271$276
Cost of removal obligations405398260259145139
Derivatives90210481154295
Commodity cost recovery39401538242
Electric transmission cost recovery19201410510
WPL’s West Riverside liquidated damages17321732
Other664538292816
$1,208$1,324$676$754$532$570


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Derivatives - Refer to Note 11 for discussion of derivative assets and derivative liabilities.

Electric transmission cost recovery - A group of MISO cooperative and municipal utilities previously filed two complaints with FERC requesting a reduction to the base return on equity used by MISO transmission owners, including ITC and ATC LLC, to determine electric transmission costs billed to utilities, including IPL and WPL. In September 2016, FERC issued an order on the first complaint and established a base return on equity of 10.32%, excluding any incentive adders granted by FERC, effective September 28, 2016, and for the refund period from November 12, 2013 through February 11, 2015 (first complaint period). During the nine months ended September 30, 2017, Alliant Energy, IPL and WPL received the refunds for the first complaint period of $50 million, $39 million and $11 million, respectively, after final true-ups. IPL and WPL each initially recorded the retail portion of the refunds to a regulatory liability. Pursuant to IUB approval, IPL’s retail portion of the refund from ITC is currently being refunded to its retail customers in 2017. WPL’s retail portion of the refund from ATC LLC will remain in a regulatory liability until such refunds are approved to be returned to retail customers in a future rate proceeding. IPL’s and WPL’s wholesale customers received their share of the refunds through normal monthly billing practices in 2017.

IPL’s tax benefit riders - IPL’s tax benefit riders utilize regulatory liabilities to credit bills of IPL’s Iowa retail electric and gas customers to help offset the impact of rate increases on such customers. These regulatory liabilities are related to tax benefits from tax accounting method changes for repairs expenditures and cost of removal expenditures, and a rate-making accounting change for capitalized interest. For the nine months ended September 30, 2017, Alliant Energy’s and IPL’s “IPL’s tax benefit riders” regulatory liabilities decreased by ($39) million as follows (in millions):
Electric tax benefit rider credits
12
($51)
Gas tax benefit rider credits(5)
Rate-making accounting change17

($39)

In the third quarter of 2017, Alliant Energy and IPL implemented a rate-making accounting change for capitalized interest. IPL currently anticipates crediting its related tax benefits from this rate-making accounting change to its Iowa retail electric and gas customers in the future, and as a result, Alliant Energy and IPL recorded an increase of $17 million to IPL’s tax benefit riders regulatory liabilities during the nine months ended September 30, 2017.

Utility Rate Reviews -
IPL’s Retail Electric Rate Review (2016 Test Year) - In April 2017, IPL filed a request with the IUB to increase annual electric base rates for its Iowa retail electric customers by $176 million, or approximately 12%. The request was based on a 2016 historical Test Year as adjusted for certain known and measurable changes occurring up to 12 months after the commencement of the proceeding. The key drivers for the filing included recovery of capital projects, primarily power grid modernization and investments that advance cleaner energy, including Marshalltown. An interim retail electric base rate increase of $102 million, or approximately 7%, on an annual basis, was implemented effective April 13, 2017, without regulatory review, and will be subject to refund pending determination of final rates. Tax benefit rider credits and MISO transmission owner return on equity refunds are expected to reduce the effect of the rate increase on customer bills in 2017 and 2018. For the three and nine months ended September 30, 2017, Alliant Energy and IPL recorded increases in electric base rates of $34 million and $54 million, respectively, in conjunction with the interim retail electric base rate increase.

In September 2017, IPL reached a partial, non-unanimous settlement agreement with the Iowa Office of Consumer Advocate, the Iowa Business Energy Coalition and the Large Energy Group for an annual electric base rate increase of $130 million, or approximately 9%. The final proposed rate increase (based on proposed settlement) includes increased depreciation expense resulting from an updated depreciation study; recovery over a four-year period of asset retirement obligation expenditures since the last retail electric rate filing in 2010; recovery over a 10-year period of the remaining net book value of Sutherland Units 1 and 3, unamortized forward contract costs for SO2 emission allowances through the energy adjustment clause and cancelled project costs approved in a prior emissions plan and budget; and no double leverage applied to the weighted-average cost of capital. The proposed settlement did not address rate design or IPL’s proposal to continue the electric transmission cost rider. As a result of the proposed settlement, in the third quarter of 2017, IPL recorded a write-down of regulatory assets of $9 million, including $4 million to “Other operation and maintenance” expenses primarily related to IPL being no longer probable of earning a return on the remaining net book value of Sutherland Units 1 and 3 from its retail customers when final rates are implemented, and $5 million to “Depreciation and amortization” expenses for asset retirement obligations deemed no longer probable of recovery in future rates. IPL currently expects to implement final rates in the first quarter of 2018. The IUB must issue a decision on requests for retail rate changes within 10 months of the date of the application for which changes are filed.


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WPL’s Retail Electric and Gas Rate Review (2017/2018 Test Period)West Riverside liquidated damages - In December 2016, WPL received an order from thePursuant to PSCW authorizing WPLauthorization, WPL’s amortization of liquidated damages related to implement an increaseWest Riverside construction procurement contracts was used to offset increases in annualWPL’s retail electric rates of $9 million, or approximately 1%,2022/2023 Test Period revenue requirement, which resulted in decreases in regulatory liabilities on Alliant Energy’s and an increaseWPL’s balance sheets and decreases in annual retail gas base rates of $9 million, or approximately 13%. The $9 million net annual retail electric rate increase reflects a $60 million increase in base rates, partially offset by a $51 million reduction in fuel-related costs, using an estimate for 2017 fuel-related costs. These increases were effective January 1, 2017depreciation and extend through the end of 2018. For the three and nine months ended September 30, 2017, Alliant Energy and WPL recorded increases in electric base rates of $4 million and $42 million, and increases in gas base rates of $2 million and $6 million, respectively, in conjunction with the base rate increases authorized in the PSCW’s December 2016 order.

WPL’s Retail Fuel-related Rate Filing (2016 Test Year) - Pursuant to a 2015 PSCW order, WPL’s 2016 fuel-related costs were subject to deferral if they were outside an annual bandwidth of plus or minus 2% of the approved annual forecasted fuel-related costs. Retail fuel-related costs incurred by WPL in 2016 were lower than fuel-related costs used to determine rates for such period resulting in an over-collection of fuel-related costs. In August 2017, the PSCW authorized WPL to utilize $6 million of the over-collections as an offset to projected 2017 fuel-related cost under-collections. As of September 30, 2017, $3 million of remaining fuel-related costs for 2016 outside of the approved bandwidth are included in “Commodity cost recovery”amortization expenses in Alliant Energy’s and WPL’s regulatory liabilities table above,income statements for the three and these costs are expected to offset any rate changes for WPL’s 2018 fuel-related costs.six months ended June 30, 2023.


WPL’s Retail Fuel-related Rate Filing (2017 Test Year) - In March 2017, WPL filed an application with the PSCW for a mid-year fuel-related cost adjustment for 2017. Fuel-related costs for 2017 are currently expected to exceed the approved 2017 fuel-related cost plan by more than the 2% annual bandwidth. In August 2017, the PSCW authorized WPL to utilize $6 million of the 2016 fuel-related cost over-collections to offset a portion of the projected fuel-related cost under-collections for 2017. As of September 30, 2017, after applying the 2016 over-recovery amounts, the remaining fuel-related costs for 2017 outside of the approved bandwidth were $3 million and are included in “Other” in Alliant Energy’s and WPL’s regulatory assets table above.

WPL’s Retail Fuel-related Rate Filing (2018 Test Year) - In July 2017, WPL filed a request with the PSCW to increase annual rates for WPL’s retail electric customers by $6 million, or approximately 1%, in 2018. The increase primarily reflects a change in expected fuel-related costs in 2018, which are expected to be offset by $3 million of over-collections from WPL’s 2016 fuel-related costs as discussed above. Any rate changes granted from this request are expected to be effective January 1, 2018.

NOTE 3. PROPERTY, PLANT AND EQUIPMENT
Utility -
Natural Gas-Fired Generation Projects -
IPL’s Marshalltown Generating Station - IPL’s constructionIn March 2023 and June 2023, Madison Gas and Electric Company and WEC Energy Group, Inc., respectively, acquired partial ownership interests in West Riverside. The related proceeds are included in “Proceeds from sales of Marshalltown, an approximate 660 MW natural gas-fired combined-cycle EGU, was completed and the EGU was placed into service in April 2017. As of September 30, 2017, Alliant Energy and IPL recorded total project costs of $643 million and AFUDC of $81 million for Marshalltown in “Property, plant and equipment, net” on their balance sheets.

WPL’s West Riverside Energy Center - WPL is currently constructing West Riverside, an approximate 730 MW natural gas-fired combined-cycle EGU. Construction began in 2016 and is currently expected to be completed by early 2020. As of September 30, 2017, Alliant Energy and WPL recorded capitalized expenditures for construction work in progress of $278 million and AFUDC of $9 million for West Riverside in “Property, plant and equipment, net” on their balance sheets. These capital expenditures do not yet reflect any potential impacts from the exercise of purchase options by certain WPL electric cooperatives for a partial ownership interest in West Riverside.

Wind Generation -
IPL’s Expansion of Wind Generation - IPL currently plans to add up to 1,000 MW of new wind projects to its existing generation portfolio. These wind projects are expected to be placed into serviceRiverside” in 2019investing activities in Alliant Energy’s and 2020. As of September 30, 2017, Alliant Energy and IPL recorded capitalized expenditures for construction work in progress of $184 million and AFUDC of $7 million for this expansion of wind generation in “Property, plant and equipment, net” on their balance sheets.


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Franklin County Wind Farm - Based on an evaluation of the strategic optionsWPL’s cash flows statements for the Franklin County wind farm performed in the third quarter of 2016, Alliant Energy concluded, as of Septembersix months ended June 30, 2016, it was probable the Franklin County wind farm would be transferred to IPL.2023. As a result Alliant Energy performed an impairment analysis of such assets and recorded non-cash, pre-tax asset valuation charges of $86 million (after-tax charges of $51 million, or $0.23 per share)these transactions, WPL’s undivided current ownership interest in the third quarter of 2016. Alliant Energy recorded such charges as a reduction to property, plant and equipment on its balance sheet in 2016 and charges to “Asset valuation charges for Franklin County wind farm” in its income statements forWest Riverside is 73.8%.

NOTE 4. RECEIVABLES
NOTE 4(a) - Accounts Receivable - For the three and ninesix months ended SeptemberJune 30, 2016. The proposed settlement2023, Alliant Energy’s, IPL’s and WPL’s gross write-offs for IPL’s retail electric rate review (2016 Test Year) included recovery of the transfer price for the Franklin County wind farm.

In April 2017, the Franklin County wind farm was transferred from AEF to IPL as approved by a February 2017 FERC order. IPL’s purchase price, including certain transaction-related costs, was $32 million. As of the closing date, the estimated fair values of the assets purchased and liabilities assumed by IPLaccounts receivable were as follows (in millions):
Originated in 2022Originated in 2023
Three MonthsSix MonthsThree MonthsSix Months
Alliant Energy$3$8$2$2
IPL2511
WPL1311
Electric plant in service
$40
Current assets2
Total assets acquired42
Other liabilities10
Net assets acquired
$32


WPL’s Proposed Acquisition of Forward Wind Energy CenterNOTE 4(b) - In October 2017, WPL entered into definitive agreements to acquire the assets of the Forward Wind Energy Center (FWEC), which is a 129 MW wind farm located in Wisconsin. WPL currently expects to acquire 55 MW of FWEC for approximately $74 million. WPL currently expects to file for approval from the PSCW and FERC in the fourth quarter of 2017, with decisions expected by the second quarter of 2018.

Retirement of IPL’s Sutherland Units 1 and 3 - In June 2017, IPL retired Sutherland Units 1 and 3 and reclassified the remaining net book value of these EGUs from property, plant and equipment to a regulatory asset on Alliant Energy’s and IPL’s balance sheets. Refer to Note 2 for further discussion.

NOTE 4. RECEIVABLES
Sales of Accounts Receivable - IPL maintains a Receivables Purchase and Sale Agreement (Receivables Agreement) whereby it may sell its customer accounts receivables, unbilled revenues and certain other accounts receivables to a third party through wholly-owned and consolidated special purpose entities. In March 2023, IPL amended and extended through March 2024 the purchase commitment from the third party to which it sells its receivables. The transfers of receivables meet the criteria for sale accounting established by the transfer of financial assets accounting rules. As of SeptemberJune 30, 2017,2023, IPL had $1.5$50 million of available capacity under its sales of accounts receivable program. For the three and nine months ended September 30, 2017 and 2016, IPL’s costs incurred related to the sales of accounts receivable program were not material.

IPL’s maximum and average outstanding cash proceeds (based on daily outstanding balances) related to the sales of accounts receivable program for the three and ninesix months ended SeptemberJune 30 were as follows (in millions):
Three MonthsSix Months
2023202220232022
Maximum outstanding aggregate cash proceeds$110$66$110$66
Average outstanding aggregate cash proceeds101187911
 Three Months Nine Months
 2017 2016 2017 2016
Maximum outstanding aggregate cash proceeds
$112.0
 
$172.0
 
$112.0
 
$172.0
Average outstanding aggregate cash proceeds66.2
 112.3
 58.7
 91.5


The attributes of IPL’s receivables sold under the Receivables Agreement were as follows (in millions):
June 30, 2023December 31, 2022
Customer accounts receivable$148$145
Unbilled utility revenues100132
Receivables sold to third party248277
Less: cash proceeds6080
Deferred proceeds188197
Less: allowance for expected credit losses1312
Fair value of deferred proceeds$175$185
 September 30, 2017 December 31, 2016
Customer accounts receivable
$153.6
 
$157.6
Unbilled utility revenues89.1
 90.4
Other receivables1.1
 0.1
Receivables sold to third party243.8
 248.1
Less: cash proceeds (a)112.0
 21.0
Deferred proceeds131.8
 227.1
Less: allowance for doubtful accounts16.5
 16.0
Fair value of deferred proceeds
$115.3
 
$211.1

(a)Changes in cash proceeds are presented in “Sales of accounts receivable” in operating activities in Alliant Energy’s and IPL’s cash flows statements.


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As of SeptemberJune 30, 2017,2023, outstanding receivables past due under the Receivables Agreement were $54.1$20 million. Additional attributes of IPL’s receivables sold under the Receivables Agreement for the three and ninesix months ended SeptemberJune 30 were as follows (in millions):
Three MonthsSix Months
2023202220232022
Collections$514$500$1,104$1,061
Write-offs, net of recoveries2143

 Three Months Nine Months
 2017 2016 2017 2016
Collections reinvested in receivables
$347.9
 
$499.7
 
$1,283.2
 
$1,362.1
Write-off losses (recoveries), net3.5
 (0.3) 10.4
 (0.6)

13
In connection with the implementation


NOTE 5. INVESTMENTS
NOTE 5(a) Unconsolidated Equity Investments -Equity Alliant Energy’s equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three and ninesix months ended SeptemberJune 30 was as follows (in millions):
Three MonthsSix Months
2023202220232022
ATC Holdings($12)($11)($25)($23)
Other(2)(5)(6)(9)
($14)($16)($31)($32)
 Alliant Energy WPL
 Three Months Nine Months Three Months Nine Months
 2017 2016 2017 2016 2017 2016 2017 2016
ATC Investment
($10.1) 
($9.1) 
($32.7) 
($28.6) 
$—
 
($9.1) 
$—
 
($28.6)
Other
 (0.1) (0.2) (0.2) (0.2) (0.2) (0.4) (0.4)
 
($10.1) 
($9.2) 
($32.9) 
($28.8) 
($0.2) 
($9.3) 
($0.4) 
($29.0)


ATC Investment - On December 31, 2016, pursuant to a June 2016 PSCW order, WPL Transco, LLC was liquidated and WPL transferred its investment in ATC LLC to ATI. As a result, WPL no longer records equity income from its prior investment in ATC LLC. There were no impacts of this transfer to Alliant Energy’s consolidated financial statements. As of December 31, 2016, ATI owns Alliant Energy’s entire investment in ATC.

Non-regulated Wind Investment in Oklahoma - In July 2017, a wholly-owned subsidiary of AEF acquired a 50% cash equity ownership interest in a 225 MW non-regulated wind farm located in Oklahoma, which started commercial operations in December 2016. The wind farm provides electricity to a third-party under a long-term purchased power agreement. In the third quarter of 2017, Alliant Energy’s “Other investments” assets increased $98 million from this acquisition. Alliant Energy will not maintain or operate the wind farm, and provided a parent guarantee of its subsidiary’s indemnification obligations under the operating agreement and purchased power agreement. Refer to Note 12(d) for discussion of the guarantee. Alliant Energy accounts for this non-regulated investment under the equity method of accounting, with the related equity (income) loss from unconsolidated investments included in the “Other” line in the above table. In conjunction with the acquisition, in July 2017, AEF entered into a $95 million, 364-day variable-rate term loan credit agreement (with Alliant Energy as guarantor).

NOTE 5(b) Cash Surrender Value of Life Insurance Policies - During the nine months ended September 30, 2016, certain of Alliant Energy’s and IPL’s company-owned life insurance policies were liquidated. The related proceeds of $31 million and $19 million were recorded in investing activities in Alliant Energy’s and IPL’s cash flows statements, respectively.

NOTE 6. COMMON EQUITY
Common Share Activity - A summary of Alliant Energy’s common stock activity was as follows:
Shares outstanding, January 1, 20172023227,673,654251,134,966 
At-the-market offering program3,074,9311,221,775 
Shareowner Direct Plan issuances496,437228,017 
Equity-based compensation plans (Note 9(b))
5,185134,334 
Other(45,847)
Shares outstanding, SeptemberJune 30, 20172023231,204,360252,719,092 


At-the-Market Offering Program - In May 2017,December 2022, Alliant Energy filed a prospectus supplement under which it couldmay sell up to $125$225 million of its common stock through an at-the-market offering program. As of SeptemberJune 30, 2017,2023, Alliant Energy issued 3,074,9311,221,775 shares of common stock through this program and received cash proceeds of $124$64 million, net of $1 million in commissions and fees. Alliant Energy also had commitments not recognized on its balance sheet at June 30, 2023 to sell 172,701 shares of common stock under sales transactions executed through this program in late June 2023. Subsequent to June 30, 2023, Alliant Energy issued shares to settle these transactions in exchange for net cash proceeds of $9 million. The proceeds from the issuances of common stock were used for general corporate purposes. Alliant Energy currently has no plans to issue any additional common stock through this at-the-market offering program.



Changes in Shareowners’ Equity - A summary of changes in shareowners’ equity was as follows (in millions):
Alliant EnergyTotal Alliant Energy Common Equity
AccumulatedShares in
AdditionalOtherDeferred
CommonPaid-InRetainedComprehensiveCompensationNoncontrollingTotal
StockCapitalEarningsIncome (Loss)TrustInterestEquity
Three Months Ended June 30, 2023
Beginning balance, March 31, 2023$3$2,780$3,559($1)($13)$—$6,328
Net income attributable to Alliant Energy common shareowners160160
Common stock dividends ($0.4525 per share)(113)(113)
At-the-market offering program and Shareowner Direct Plan issuances7070
Equity-based compensation plans and other4(1)3
Other comprehensive income, net of tax44
Ending balance, June 30, 2023$3$2,854$3,606$3($14)$—$6,452
Three Months Ended June 30, 2022
Beginning balance, March 31, 2022$3$2,750$3,336$—($12)$—$6,077
Net income attributable to Alliant Energy common shareowners159159
Common stock dividends ($0.4275 per share)(108)(108)
Shareowner Direct Plan issuances66
Equity-based compensation plans and other33
Contributions from noncontrolling interest2929
Ending balance, June 30, 2022$3$2,759$3,387$—($12)$29$6,166
1714


Alliant EnergyTotal Alliant Energy Common Equity
AccumulatedShares in
AdditionalOtherDeferred
CommonPaid-InRetainedComprehensiveCompensationNoncontrollingTotal
StockCapitalEarningsIncome (Loss)TrustInterestEquity
Six Months Ended June 30, 2023
Beginning balance, December 31, 2022$3$2,777$3,509$—($13)$—$6,276
Net income attributable to Alliant Energy common shareowners323323
Common stock dividends ($0.905 per share)(226)(226)
At-the-market offering program and Shareowner Direct Plan issuances7676
Equity-based compensation plans and other1(1)
Other comprehensive income, net of tax33
Ending balance, June 30, 2023$3$2,854$3,606$3($14)$—$6,452
Six Months Ended June 30, 2022
Beginning balance, December 31, 2021$3$2,749$3,250$—($12)$—$5,990
Net income attributable to Alliant Energy common shareowners351351
Common stock dividends ($0.855 per share)(215)(215)
Shareowner Direct Plan issuances1313
Equity-based compensation plans and other(3)1(2)
Contributions from noncontrolling interest2929
Ending balance, June 30, 2022$3$2,759$3,387$—($12)$29$6,166
Dividend Restrictions - As of September 30, 2017, IPL’s amount of retained earnings that were free of dividend restrictions was $701 million. As of September 30, 2017, WPL’s amount of retained earnings that were free of dividend restrictions was $32 million for the remainder of 2017.
IPLAdditionalTotal
CommonPaid-InRetainedCommon
StockCapitalEarningsEquity
Three Months Ended June 30, 2023
Beginning balance, March 31, 2023$33$2,807$970$3,810
Net income8989
Common stock dividends(70)(70)
Capital contributions from parent4040
Ending balance, June 30, 2023$33$2,847$989$3,869
Three Months Ended June 30, 2022
Beginning balance, March 31, 2022$33$2,807$935$3,775
Net income8787
Common stock dividends(80)(80)
Ending balance, June 30, 2022$33$2,807$942$3,782

IPLAdditionalTotal
CommonPaid-InRetainedCommon
StockCapitalEarningsEquity
Six Months Ended June 30, 2023
Beginning balance, December 31, 2022$33$2,807$968$3,808
Net income161161
Common stock dividends(140)(140)
Capital contributions from parent4040
Ending balance, June 30, 2023$33$2,847$989$3,869
Six Months Ended June 30, 2022
Beginning balance, December 31, 2021$33$2,807$929$3,769
Net income173173
Common stock dividends(160)(160)
Ending balance, June 30, 2022$33$2,807$942$3,782
Restricted Net Assets of Subsidiaries - As of September 30, 2017, the amount of IPL’s and WPL’s net assets that were not available to be transferred to their parent company, Alliant Energy, in the form of loans, advances or cash dividends without the consent of IPL’s and WPL’s regulatory authorities was $1.7 billion and $1.8 billion, respectively.

15

Comprehensive Income - For the three and nine months ended September 30, 2017 and 2016, Alliant Energy had no other comprehensive income; therefore, its comprehensive income was equal to its net income and its comprehensive income attributable to Alliant Energy common shareowners was equal to its net income attributable to Alliant Energy common shareowners for such periods. For the three and nine months ended September 30, 2017 and 2016, IPL and WPL had no other comprehensive income; therefore, their comprehensive income was equal to their net income and their comprehensive income available for common stock was equal to their earnings available for common stock for such periods.
WPLTotal WPL Common Equity
Additional
CommonPaid-InRetainedNoncontrollingTotal
StockCapitalEarningsInterestEquity
Three Months Ended June 30, 2023
Beginning balance, March 31, 2023$66$2,413$1,234$—$3,713
Net income7272
Common stock dividends(46)(46)
Ending balance, June 30, 2023$66$2,413$1,260$—$3,739
Three Months Ended June 30, 2022
Beginning balance, March 31, 2022$66$1,884$1,101$—$3,051
Net income6363
Common stock dividends(44)(44)
Capital contributions from parent8585
Contributions from noncontrolling interest2929
Other(1)(1)
Ending balance, June 30, 2022$66$1,968$1,120$29$3,183

WPLTotal WPL Common Equity
Additional
CommonPaid-InRetainedNoncontrollingTotal
StockCapitalEarningsInterestEquity
Six Months Ended June 30, 2023
Beginning balance, December 31, 2022$66$2,233$1,192$—$3,491
Net income160160
Common stock dividends(92)(92)
Capital contributions from parent180180
Ending balance, June 30, 2023$66$2,413$1,260$—$3,739
Six Months Ended June 30, 2022
Beginning balance, December 31, 2021$66$1,704$1,053$—$2,823
Net income156156
Common stock dividends(89)(89)
Capital contributions from parent265265
Contributions from noncontrolling interest2929
Other(1)(1)
Ending balance, June 30, 2022$66$1,968$1,120$29$3,183

NOTE 7. DEBT
NoteNOTE 7(a) Short-term Debt - In August 2017,March 2023, Alliant Energy, IPL and WPL entered into aextended their single new credit facility agreement, which currently expires in August 2022. The newDecember 2027, and reallocated credit facility agreement includes financial covenants similarcapacity amounts to those that were included in the previous credit facility agreements. As of September 30, 2017, the short-term borrowing capacity under the new credit facility agreement totaled $1 billion ($300$450 million for Alliant Energy at the parent company level, $300$250 million for IPL and $400$300 million for WPL). Subject to certain conditions, Alliant Energy (at the parent company level), IPL and WPL, may each reallocate and change its initial sublimit up to $500 million, $400 million and $500 million, respectively, within the $1 billion total commitment. Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper classified as short-term debt was as follows (dollars in millions):
June 30, 2023Alliant EnergyIPLWPL
Amount outstanding$391$—$44
Weighted average interest rates5.3%—%5.2%
Available credit facility capacity (a)$554$195$256
Alliant EnergyIPLWPL
Three Months Ended June 30202320222023202220232022
Maximum amount outstanding (based on daily outstanding balances)$391$441$70$—$91$222
Average amount outstanding (based on daily outstanding balances)$88$337$6$—$18$166
Weighted average interest rates5.3%1.0%5.3%—%5.2%0.9%
Six Months Ended June 30
Maximum amount outstanding (based on daily outstanding balances)$793$577$70$—$349$252
Average amount outstanding (based on daily outstanding balances)$330$390$3$—$160$185
Weighted average interest rates4.8%0.6%5.3%—%4.8%0.5%

(a)Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at June 30, 2023.
September 30, 2017Alliant Energy IPL WPL
Commercial paper outstanding$390.3 $4.0 $224.6
Commercial paper weighted average interest rates1.2% 1.4% 1.1%
Available credit facility capacity (a)$569.7 $256.0 $175.4
 Alliant Energy IPL WPL
Three Months Ended September 302017 2016 2017 2016 2017 2016
Maximum amount outstanding (based on daily outstanding balances)$424.4 $248.0 $20.0 $3.1 $271.2 $55.4
Average amount outstanding (based on daily outstanding balances)$386.2 $220.1 $0.4 $0.1 $217.0 $36.4
Weighted average interest rates1.3% 0.6% 1.4% 0.6% 1.1% 0.4%
Nine Months Ended September 30           
Maximum amount outstanding (based on daily outstanding balances)$424.4 $248.0 $20.0 $3.1 $271.2 $62.9
Average amount outstanding (based on daily outstanding balances)$323.9 $210.7 $0.5 $— $144.2 $33.2
Weighted average interest rates1.1% 0.6% 1.2% 0.6% 1.0% 0.4%

(a)Alliant Energy’s and IPL’s available credit facility capacities reflect outstanding commercial paper classified as both short- and long-term debt at September 30, 2017.16


In July 2017,January 2023, AEF entered into a $95received $50 million 364-day variable-rate (1.8% at September 30, 2017)of proceeds from its December 2022 term loan credit agreement, (with Alliant Energywhich was classified as guarantor) related to the acquisition of a non-regulated wind farm located in Oklahoma, which includes substantially the same financial covenants that are included in“Other short-term borrowings” on Alliant Energy’s current credit facility agreement. Refer to Note 5(a) for further discussionbalance sheet as of the non-regulated wind farm acquisition.June 30, 2023.


NOTE 7(b) Long-term Debt - In June 2023, AEF retired its $400 million 3.75% senior notes. In March 2023, WPL issued $300 million of 4.95% debentures due 2033. WPL’s debentures were issued as green bonds, and an amount equal to or in excess of the net proceeds will be allocated or disbursed for the development and acquisition of its solar EGUs.

As of SeptemberJune 30, 2017, $40.02023, $55 million of commercial paper was recorded in “Long-term debt, net” on Alliant Energy’s and IPL’s balance sheets due to the existence of athe long-term single credit facility that back-stops this commercial paper balance, along with Alliant Energy’s and IPL’s intent and ability to refinance these balances on a long-term basis. As of SeptemberJune 30, 2017,2023, this commercial paper balance had a 1.4%5% interest rate.


Convertible Senior Notes - In October 2017, WPLMarch 2023, Alliant Energy issued $300$575 million of 3.05% debentures due 2027. The3.875% convertible senior notes (the Notes), which are senior unsecured obligations, and used the net proceeds from the issuance were used by WPL to reduce commercial paper and for general corporate purposes. The Notes will mature on March 15, 2026 unless earlier converted or repurchased, and no sinking fund is provided for the Notes. Alliant Energy may not redeem the Notes prior to the maturity date. Holders may convert their Notes at their option at any time prior to the close of business on the business day immediately preceding December 15, 2025 only under the following circumstances:



during any calendar quarter commencing after the calendar quarter ending on June 30, 2023 (and only during such calendar quarter), if the last reported sale price of Alliant Energy’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day during such period;
during the 5 business day period after any 10 consecutive trading day period (the “measurement period”) in which the trading price (as defined in the related Indenture) per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of Alliant Energy’s common stock and the conversion rate on each such trading day; or
upon the occurrence of specified corporate events.

On or after December 15, 2025 until the close of business on the business day immediately preceding the maturity date, holders may convert all or any portion of their Notes at any time, regardless of the foregoing circumstances. Upon conversion of the Notes, Alliant Energy will pay cash up to the aggregate principal amount of the Notes to be converted and pay or deliver, as the case may be, cash, shares of its common stock or a combination of cash and shares of its common stock, at its election, in respect of the remainder, if any, of its conversion obligation in excess of the aggregate principal amount of the Notes being converted.

The initial conversion rate is 15.5461 shares of common stock per $1,000 principal amount of Notes (equivalent to an initial conversion price of approximately $64.32 per share of Alliant Energy’s common stock). The conversion rate is subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date, Alliant Energy will, in certain circumstances, increase the conversion rate for a holder who elects to convert its Notes in connection with such a corporate event.

If Alliant Energy undergoes a fundamental change (as defined in the related Indenture), then, subject to certain conditions, holders of the Notes may require Alliant Energy to repurchase for cash all or any portion of its Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.

As of June 30, 2023, the conditions allowing holders of the Notes to convert their Notes were not met, and as a result, the Notes were classified as “Long-term debt, net” on Alliant Energy’s balance sheet. As of June 30, 2023, the net carrying amount of the Notes was $566 million, with unamortized debt issuance costs of $9 million, and the estimated fair value (Level 2) of the Notes was $573 million. As of June 30, 2023, there were no shares of Alliant Energy’s common stock related to the potential conversion of the Notes included in diluted EPS based on Alliant Energy’s average stock prices and the relevant terms of the Notes.

1817


NOTE 8. REVENUES
Disaggregation of revenues from contracts with customers, which correlates to revenues for each reportable segment, was as follows (in millions):
Alliant EnergyIPLWPL
Three Months Ended June 30202320222023202220232022
Electric Utility:
Retail - residential$284$289$151$158$133$131
Retail - commercial2011961291277269
Retail - industrial245244130136115108
Wholesale495414163538
Bulk power and other2029751324
Total Electric Utility799812431442368370
Gas Utility:
Retail - residential425124281823
Retail - commercial222712141013
Retail - industrial332211
Transportation/other10136845
Total Gas Utility779444523342
Other Utility:
Steam11111111
Other utility221111
Total Other Utility1313121211
Non-Utility and Other:
Travero and other2324
Total Non-Utility and Other2324
Total revenues$912$943$487$506$402$413
Alliant EnergyIPLWPL
Six Months Ended June 30202320222023202220232022
Electric Utility:
Retail - residential$569$581$294$308$275$273
Retail - commercial385386241246144140
Retail - industrial460453236246224207
Wholesale9510126316970
Bulk power and other586522123653
Total Electric Utility1,5671,586819843748743
Gas Utility:
Retail - residential2102101171139397
Retail - commercial11010956545455
Retail - industrial9116734
Transportation/other2426151799
Total Gas Utility353356194191159165
Other Utility:
Steam22202220
Other utility332211
Total Other Utility2523242211
Non-Utility and Other:
Travero and other4547
Total Non-Utility and Other4547
Total revenues$1,990$2,012$1,037$1,056$908$909

NOTE 9. INCOME TAXES
Income Tax Rates - The overallOverall effective income tax rates, shown in the following tablewhich were computed by dividing income tax expense (benefit) by income from continuing operations before income taxes.taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences.
 Alliant Energy IPL WPL
Three Months Ended September 302017 2016 2017 2016 2017 2016
Statutory federal income tax rate35.0 % 35.0 % 35.0% 35.0% 35.0 % 35.0 %
Effect of rate-making on property-related differences(10.1) (11.9) (22.6) (16.5) (1.9) (0.7)
IPL’s tax benefit riders(8.3) (13.1) (20.9) (20.1) 
 
Production tax credits(6.2) (9.0) (7.0) (6.0) (7.0) (5.7)
Other items, net2.8
 4.4
 2.3
 5.4
 5.5
 4.0
Overall income tax rate13.2% 5.4% (13.2%) (2.2%) 31.6% 32.6%
18

 Alliant Energy IPL WPL
Nine Months Ended September 302017 2016 2017 2016 2017 2016
Statutory federal income tax rate35.0 % 35.0 % 35.0% 35.0% 35.0 % 35.0 %
Effect of rate-making on property-related differences(9.1) (8.2) (20.6) (14.8) (1.8) (0.8)
IPL’s tax benefit riders(8.1) (10.2) (20.1) (19.6) 
 
Production tax credits(6.0) (7.2) (6.8) (6.1) (7.0) (6.1)
Other items, net3.1
 3.5
 2.7
 4.2
 4.9
 4.4
Overall income tax rate14.9% 12.9% (9.8%) (1.3%) 31.1% 32.5%
Alliant EnergyIPLWPL
Three MonthsSix MonthsThree MonthsSix MonthsThree MonthsSix Months
202320222023202220232022202320222023202220232022
Overall income tax rate—%2%(1%)3%(17%)(16%)(18%)(15%)16%18%14%18%


Deferred Tax Assets and Liabilities -For the nine months ended September 30, 2017, Alliant Energy’s, IPL’s and WPL’s deferred tax liabilities increased $204.5 million, $131.7 million and $63.6 million, respectively. These increases were primarily due to property-related differences recorded during the nine months ended September 30, 2017. Alliant Energy’s and IPL’s increases were partially offset by the generation of federal net operating losses recorded during the nine months ended September 30, 2017, which are primarily due to accelerated tax depreciation associated with Marshalltown.

Carryforwards - At SeptemberJune 30, 2017,2023, the carryforwards and expiration dates were estimated as follows (in millions):
Range of Expiration DatesAlliant EnergyIPLWPL
State net operating losses2025-2043$503$8$1
Federal tax credits2030-2043708485214
 Range of Expiration Dates Alliant Energy IPL WPL
Federal net operating losses2030-2037 
$815
 
$500
 
$208
State net operating losses2018-2037 701
 14
 2
Federal tax credits2022-2037 297
 110
 125


NOTE 9.10. BENEFIT PLANS
NOTE 9(a)10(a) Pension and Other Postretirement BenefitsOPEB Plans -
Net Periodic Benefit Costs - The components of net periodic benefit costs for sponsored defined benefit pension and OPEB plans for the three and ninesix months ended SeptemberJune 30 are included in the tables below (in millions). In IPL’sFor IPL and WPL’s tables below, the defined benefit pension planWPL, amounts represent those respective amountsare for their bargaining unit employeesplan participants covered under the qualified plans that they sponsor, as well as amounts directly assigned to them related to their current and former non-bargaining employees who arecertain participants in the Alliant Energy and Corporate Services sponsored qualified and non-qualified defined benefit pension plans. In IPL’s and WPL’s tables below, the OPEB plans amounts represent respective amounts for their employees, as well as amounts directly assigned to them related to their current and former non-bargaining employees who are participants in the Corporate Services sponsored OPEB plan.
Defined Benefit Pension PlansOPEB Plans
Three MonthsSix MonthsThree MonthsSix Months
Alliant Energy20232022202320222023202220232022
Service cost$1$2$2$4$—$1$1$2
Interest cost12923182243
Expected return on plan assets(13)(17)(26)(34)(1)(2)(2)(3)
Amortization of actuarial loss781416111
$7$2$13$4$2$1$4$3
Defined Benefit Pension PlansOPEB Plans
Defined Benefit Pension Plans OPEB PlansThree MonthsSix MonthsThree MonthsSix Months
Three Months Nine Months Three Months Nine Months
Alliant Energy2017 2016 2017 2016 2017 2016 2017 2016
IPLIPL20232022202320222023202220232022
Service cost
$3.1
 
$3.2
 
$9.3
 
$9.5
 
$1.2
 
$1.4
 
$3.7
 
$4.0
Service cost$1$1$2$3$—$1$—$1
Interest cost12.7
 13.2
 38.3
 39.7
 2.2
 2.3
 6.5
 7.0
Interest cost54108121
Expected return on plan assets(16.3) (16.3) (49.1) (49.1) (1.5) (1.6) (4.6) (4.6)Expected return on plan assets(6)(8)(13)(16)(1)(1)(2)(2)
Amortization of prior service credit(0.1) (0.1) (0.3) (0.2) (0.1) (1.0) (0.2) (3.1)
Amortization of actuarial loss9.4
 9.3
 28.2
 28.0
 1.0
 1.2
 2.9
 3.6
Amortization of actuarial loss346711
Settlement losses (a)0.9
 
 0.9
 
 
 
 
 

$9.7
 
$9.3
 
$27.3
 
$27.9
 
$2.8
 
$2.3
 
$8.3
 
$6.9
$3$1$5$2$1$—$1$—

Defined Benefit Pension PlansOPEB Plans
Three MonthsSix MonthsThree MonthsSix Months
WPL20232022202320222023202220232022
Service cost$1$1$1$2$—$—$—$—
Interest cost54108121
Expected return on plan assets(6)(8)(11)(16)
Amortization of actuarial loss447811
$4$1$7$2$1$1$2$2

19



 Defined Benefit Pension Plans OPEB Plans
 Three Months Nine Months Three Months Nine Months
IPL2017 2016 2017 2016 2017 2016 2017 2016
Service cost
$1.8
 
$1.8
 
$5.5
 
$5.6
 
$0.5
 
$0.5
 
$1.6
 
$1.7
Interest cost5.9
 6.1
 17.6
 18.4
 0.8
 1.0
 2.6
 2.9
Expected return on plan assets(7.7) (7.7) (23.1) (23.2) (1.0) (1.0) (3.2) (3.2)
Amortization of prior service credit
 
 (0.1) (0.1) 
 (0.7) 
 (2.0)
Amortization of actuarial loss4.0
 4.2
 12.1
 12.4
 0.5
 0.7
 1.5
 2.0
 
$4.0
 
$4.4
 
$12.0
 
$13.1
 
$0.8
 
$0.5
 
$2.5
 
$1.4
 Defined Benefit Pension Plans OPEB Plans
 Three Months Nine Months Three Months Nine Months
WPL2017 2016 2017 2016 2017 2016 2017 2016
Service cost
$1.2
 
$1.3
 
$3.6
 
$3.7
 
$0.5
 
$0.5
 
$1.4
 
$1.5
Interest cost5.5
 5.5
 16.4
 16.7
 0.9
 0.9
 2.6
 2.8
Expected return on plan assets(7.2) (7.0) (21.4) (21.2) (0.2) (0.2) (0.6) (0.6)
Amortization of prior service cost (credit)0.1
 
 0.1
 0.1
 (0.1) (0.3) (0.2) (0.7)
Amortization of actuarial loss4.6
 4.4
 13.9
 13.2
 0.4
 0.5
 1.2
 1.4
 
$4.2
 
$4.2
 
$12.6
 
$12.5
 
$1.5
 
$1.4
 
$4.4
 
$4.4

(a)Settlement losses related to payments made to retired executives of Alliant Energy.

NOTE 9(b)10(b) Equity-based Compensation Plans - A summary of compensation expense, including amounts allocated to IPL and WPL, and the related income tax benefits recognized for share-based compensation awards for the three and ninesix months ended SeptemberJune 30 was as follows (in millions):
Alliant EnergyIPLWPL
Three MonthsSix MonthsThree MonthsSix MonthsThree MonthsSix Months
202320222023202220232022202320222023202220232022
Compensation expense$3$3$6$7$2$1$3$4$1$1$2$3
Income tax benefits11221111
 Alliant Energy IPL WPL
 Three Months Nine Months Three Months Nine Months Three Months Nine Months
 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016
Compensation expense
$5.1
 
$4.4
 
$9.9
 
$16.8
 
$2.8
 
$2.4
 
$5.4
 
$8.9
 
$2.1
 
$1.9
 
$4.1
 
$7.3
Income tax benefits2.1
 1.7
 4.0
 6.8
 1.1
 1.0
 2.2
 3.7
 0.9
 0.7
 1.7
 2.9


As of SeptemberJune 30, 2017,2023, Alliant Energy’s, IPL’s and WPL’s total unrecognized compensation cost related to share-based compensation awards was $8.5$15 million, $4.7$8 million and $3.5$6 million, respectively, which is expected to be recognized over a weighted average period of between one1 year and two2 years.

Performance Shares and Performance Units - A summary of the performance shares and performance units activity for the nine months ended September 30, 2017, with amounts representing the target number of awards, was as follows:
 Performance Shares Performance Units
Nonvested awards, January 1257,599
 93,320
Granted65,350
 21,558
Vested(99,438) (37,395)
Forfeited
 (4,243)
Nonvested awards, September 30223,511
 73,240

Vested Awards - During the nine months ended September 30, 2017, certain performance shares and performance units that were granted in 2014 vested, resulting in payouts (a combination of cash and common stock for the performance shares and cash only for the performance units) as follows:
 Performance Shares Performance Units
Performance awards vested99,438
 37,395
Percentage of target number of performance awards147.5% 147.5%
Aggregate payout value (in millions)
$5.6
 
$1.5
Payout - cash (in millions)
$5.1
 
$1.5
Payout - common stock shares issued5,185
 N/A



2019


Fair Value of Awards - Information related to fair values of nonvestedFor the six months ended June 30, 2023, performance shares, and performance units at September 30, 2017, by year of grant, was as follows:
 Performance Shares Performance Units
 2017 Grant 2016 Grant 2015 Grant 2017 Grant 2016 Grant 2015 Grant
Nonvested awards at target65,350
 67,355
 90,806
 19,531
 21,751
 31,958
Alliant Energy common stock closing price on September 29, 2017
$41.57
 
$41.57
 
$41.57
 
$41.57
 
$41.57
 N/A
Alliant Energy common stock closing price on grant dateN/A N/A N/A N/A N/A 
$32.55
Estimated payout percentage based on performance criteria100% 138% 113% 100% 138% 113%
Fair values of each nonvested award
$41.57
 
$57.37
 
$46.97
 
$41.57
 
$57.37
 
$36.78

Performance Restricted Stock Units - A summary of the performance restricted stock units activity for the nine months ended September 30, 2017, with amounts representing the target number of units, was as follows:
 Units 
Weighted Average
Grant Date Fair Value
Nonvested units, January 167,355
 
$33.96
Granted65,350
 39.12
Nonvested units, September 30132,705
 36.50

Restricted Stock Units - A summary of theand restricted stock units activitywere granted to key employees under existing plans as follows. These shares and units will be paid out in shares of common stock, and are therefore accounted for as equity awards.
Weighted Average
GrantsGrant Date Fair Value
Performance shares106,927$55.68
Performance restricted stock units122,17852.77
Restricted stock units104,84952.81

As of June 30, 2023, 206,177 shares were included in the nine months ended September 30, 2017, was as follows:calculation of diluted EPS related to the nonvested equity awards.

Nonvested units, January 157,736
Granted56,013
Nonvested units, September 30113,749

NOTE 10. FAIR VALUE MEASUREMENTS
Valuation Hierarchy - At each reporting date, Level 1 items included IPL’s 5.1% cumulative preferred stock, Level 2 items included certain non-exchange traded commodity contracts and substantially all of the long-term debt instruments, and Level 3 items included FTRs, certain non-exchange traded commodity contracts and IPL’s deferred proceeds.

Fair Value of Financial Instruments - The carrying amounts of current assets and current liabilities approximate fair value because of the short maturity of such financial instruments. Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):
Alliant EnergySeptember 30, 2017 December 31, 2016
   Fair Value   Fair Value
 Carrying Level Level Level   Carrying Level Level Level  
 Amount 1 2 3 Total Amount 1 2 3 Total
Assets:                   
Derivatives
$29.4
 
$—
 
$2.9
 
$26.5
 
$29.4
 
$41.4
 
$—
 
$4.6
 
$36.8
 
$41.4
Deferred proceeds115.3
 
 
 115.3
 115.3
 211.1
 
 
 211.1
 211.1
Liabilities and equity:                   
Derivatives45.1
 
 14.9
 30.2
 45.1
 28.6
 
 0.5
 28.1
 28.6
Long-term debt (incl. current maturities)4,360.3
 
 4,893.3
 2.9
 4,896.2
 4,320.2
 
 4,795.7
 3.3
 4,799.0
Cumulative preferred stock of IPL200.0
 202.3
 
 
 202.3
 200.0
 194.8
 
 
 194.8

21



IPLSeptember 30, 2017 December 31, 2016
   Fair Value   Fair Value
 Carrying Level Level Level   Carrying Level Level Level  
 Amount 1 2 3 Total Amount 1 2 3 Total
Assets:                   
Derivatives
$21.1
 
$—
 
$1.6
 
$19.5
 
$21.1
 
$20.8
 
$—
 
$2.8
 
$18.0
 
$20.8
Deferred proceeds115.3
 
 
 115.3
 115.3
 211.1
 
 
 211.1
 211.1
Liabilities and equity:                   
Derivatives18.7
 
 4.5
 14.2
 18.7
 8.3
 
 0.4
 7.9
 8.3
Long-term debt (incl. current maturities)2,195.0
 
 2,430.1
 
 2,430.1
 2,153.5
 
 2,352.3
 
 2,352.3
Cumulative preferred stock200.0
 202.3
 
 
 202.3
 200.0
 194.8
 
 
 194.8
WPLSeptember 30, 2017 December 31, 2016
   Fair Value   Fair Value
 Carrying Level Level Level   Carrying Level Level Level  
 Amount 1 2 3 Total Amount 1 2 3 Total
Assets:                   
Derivatives
$8.3
 
$—
 
$1.3
 
$7.0
 
$8.3
 
$20.6
 
$—
 
$1.8
 
$18.8
 
$20.6
Liabilities:                   
Derivatives26.4
 
 10.4
 16.0
 26.4
 20.3
 
 0.1
 20.2
 20.3
Long-term debt1,536.2
 
 1,829.3
 
 1,829.3
 1,535.2
 
 1,807.4
 
 1,807.4

Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):
Alliant EnergyCommodity Contract Derivative  
 Assets and (Liabilities), net Deferred Proceeds
Three Months Ended September 302017 2016 2017 2016
Beginning balance, July 1
$9.2
 
$0.6
 
$170.0
 
$74.4
Total net losses included in changes in net assets (realized/unrealized)(4.3) (5.1) 
 
Transfers out of Level 3
 0.8
 
 
Sales(0.1) (0.2) 
 
Settlements (a)(8.5) (4.0) (54.7) 165.3
Ending balance, September 30
($3.7) 
($7.9) 
$115.3
 
$239.7
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30
($4.2) 
($5.0) 
$—
 
$—
Alliant EnergyCommodity Contract Derivative  
 Assets and (Liabilities), net Deferred Proceeds
Nine Months Ended September 302017 2016 2017 2016
Beginning balance, January 1
$8.7
 
($32.7) 
$211.1
 
$172.0
Total net gains (losses) included in changes in net assets (realized/unrealized)(31.3) 8.0
 
 
Transfers into Level 3
 0.9
 
 
Transfers out of Level 312.2
 1.2
 
 
Purchases28.3
 22.0
 
 
Sales(0.3) (0.9) 
 
Settlements (a)(21.3) (6.4) (95.8) 67.7
Ending balance, September 30
($3.7) 
($7.9) 
$115.3
 
$239.7
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30
($29.4) 
$9.7
 
$—
 
$—

22



IPLCommodity Contract Derivative  
 Assets and (Liabilities), net Deferred Proceeds
Three Months Ended September 302017 2016 2017 2016
Beginning balance, July 1
$17.1
 
$18.3
 
$170.0
 
$74.4
Total net losses included in changes in net assets (realized/unrealized)(4.4) (0.4) 
 
Transfers out of Level 3
 0.3
 
 
Sales(0.1) (0.2) 
 
Settlements (a)(7.3) (4.6) (54.7) 165.3
Ending balance, September 30
$5.3
 
$13.4
 
$115.3
 
$239.7
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at September 30
($4.5) 
($0.4) 
$—
 
$—
IPLCommodity Contract Derivative  
 Assets and (Liabilities), net Deferred Proceeds
Nine Months Ended September 302017 2016 2017 2016
Beginning balance, January 1
$10.1
 
($1.9) 
$211.1
 
$172.0
Total net gains (losses) included in changes in net assets (realized/unrealized)(13.9) 4.8
 
 
Transfers into Level 3
 0.5
 
 
Transfers out of Level 33.1
 0.2
 
 
Purchases24.6
 20.6
 
 
Sales(0.2) (0.9) 
 
Settlements (a)(18.4) (9.9) (95.8) 67.7
Ending balance, September 30
$5.3
 
$13.4
 
$115.3
 
$239.7
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30
($12.6) 
$5.7
 
$—
 
$—
WPLCommodity Contract Derivative
 Assets and (Liabilities), net
Three Months Ended September 302017 2016
Beginning balance, July 1
($7.9) 
($17.7)
Total net gains (losses) included in changes in net assets (realized/unrealized)0.1
 (4.7)
Transfers out of Level 3
 0.5
Settlements(1.2) 0.6
Ending balance, September 30
($9.0) 
($21.3)
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30
$0.3
 
($4.6)
WPLCommodity Contract Derivative
 Assets and (Liabilities), net
Nine Months Ended September 302017 2016
Beginning balance, January 1
($1.4) 
($30.8)
Total net gains (losses) included in changes in net assets (realized/unrealized)(17.4) 3.2
Transfers into Level 3
 0.4
Transfers out of Level 39.1
 1.0
Purchases3.7
 1.4
Sales(0.1) 
Settlements(2.9) 3.5
Ending balance, September 30
($9.0) 
($21.3)
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30
($16.8) 
$4.0

(a)Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold.


23



Commodity Contracts - The fair value of electric, natural gas, coal and diesel fuel commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions):
 Alliant Energy IPL WPL
 Excluding FTRs FTRs Excluding FTRs FTRs Excluding FTRs FTRs
September 30, 2017
($22.2) 
$18.5
 
($10.4) 
$15.7
 
($11.8) 
$2.8
December 31, 2016(2.3) 11.0
 0.1
 10.0
 (2.4) 1.0

NOTE 11. DERIVATIVE INSTRUMENTS
Commodity Derivatives -
Notional Amounts - As of SeptemberJune 30, 2017,2023, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts FTRs, coal contracts and diesel fuel contractsFTRs that were accounted for as commodity derivative instruments were as follows (units in thousands):
ElectricityFTRsNatural GasCoal
MWhsYearsMWhsYearsDthsYearsTonsYears
Alliant Energy1,1712023-202524,874 2023-2024192,421 2023-2032466 2023
IPL5372023-202510,163 2023-202492,087 2023-2030224 2023
WPL6342023-202514,711 2023-2024100,334 2023-2032242 2023
 Electricity FTRs Natural Gas Coal Diesel Fuel
 MWhs Years MWhs Years Dths Years Tons Years Gallons Years
Alliant Energy1,645
 2017-2018 14,745
 2017-2018 173,234
 2017-2026 4,963
 2017-2019 7,308
 2017-2019
IPL
  9,219
 2017-2018 79,561
 2017-2026 1,820
 2017-2019 
 
WPL1,645
 2017-2018 5,526
 2017-2018 93,673
 2017-2026 3,143
 2017-2018 7,308
 2017-2019


Financial Statement Presentation - Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities. The fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions):
Alliant EnergyIPLWPL
June 30,
2023
December 31,
2022
June 30,
2023
December 31,
2022
June 30,
2023
December 31,
2022
Current derivative assets$86$111$61$69$25$42
Non-current derivative assets6112634692757
Current derivative liabilities545927402719
Non-current derivative liabilities43201063314
 Alliant Energy IPL WPL
 September 30,
2017
 December 31,
2016
 September 30,
2017
 December 31,
2016
 September 30,
2017
 December 31,
2016
Current derivative assets
$26.7
 
$29.4
 
$20.3
 
$19.1
 
$6.4
 
$10.3
Non-current derivative assets2.7
 12.0
 0.8
 1.7
 1.9
 10.3
Current derivative liabilities18.5
 13.3
 4.6
 2.7
 13.9
 10.6
Non-current derivative liabilities26.6
 15.3
 14.1
 5.6
 12.5
 9.7


During the six months ended June 30, 2023, Alliant Energy’s, IPL’s and WPL’s derivative assets decreased primarily due to settlements of natural gas, FTR and electricity contracts and lower natural gas prices, partially offset by new FTRs resulting from the annual FTR auction in the second quarter of 2023 operated by MISO. Alliant Energy’s and WPL’s derivative liabilities increased primarily due to lower natural gas prices. Based on IPL’s and WPL’s cost recovery mechanisms, the changes in the fair value of derivative liabilities/assets resulted in comparable changes to regulatory assets/liabilities on the balance sheets.

Credit Risk-related Contingent Features - Various agreements contain credit risk-related contingent features, including requirements to maintain certain credit ratings and/or limitations on liability positions under the agreements based on credit ratings. Certain of these agreements with credit risk-related contingency features are accounted for as derivative instruments. In the event of a material change in creditworthiness or if liability positions exceed certain contractual limits, credit support may need to be provided in the form of letters of credit or cash collateral up to the amount of exposure under the contracts, or the contracts may need to be unwound and underlying liability positions paid. At SeptemberJune 30, 20172023 and December 31, 2016,2022, the aggregate fair value of all derivative instruments with credit risk-related contingent features in a net liability position was not materially different different than amounts that would be required to be posted as credit support to counterparties by Alliant Energy, IPL or WPL if the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered.


Balance Sheet Offsetting - The fair value amounts of derivative instruments subject to a master netting arrangement are not netted by counterparty on the balance sheets. However, if the fair value amounts of derivative instruments by counterparty were netted, amounts would not be materially different from gross amounts of derivative assets and derivative liabilities at September 30, 2017 and December 31, 2016. related to commodity contracts would have been presented on the balance sheets as follows (in millions):
20

Alliant EnergyIPLWPL
GrossGrossGross
(as reported)Net(as reported)Net(as reported)Net
June 30, 2023
Derivative assets$147$114$95$73$52$41
Derivative liabilities976437156049
December 31, 2022
Derivative assets2371931381089985
Derivative liabilities793546163319

Fair value amounts recognized for the right to reclaim cash collateral (receivable) or the obligation to return cash collateral (payable) are not offset against fair value amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement.


Interest Rate Derivative - In January 2023, AEF entered into a $300 million interest rate swap maturing in January 2026 to mitigate interest rate risk. Under the terms of the swap, AEF exchanged a variable interest rate for a fixed interest rate of 3.93% on a portion of its variable-rate term loan borrowings. The related interest rate derivative was valued based on quoted prices that utilize current market interest rate forecasts. As of June 30, 2023, $4 million of non-current interest rate derivative assets was recorded in “Deferred charges and other” on Alliant Energy’s balance sheet. This interest rate derivative was designated as a cash flow hedge, with changes in fair value recorded as other comprehensive income/loss. As of June 30, 2023, accumulated other comprehensive income included $3 million of income related to the interest rate swap. For the three and six months ended June 30, 2023, $1 million and $1 million, respectively, of reductions to interest expense were recorded in Alliant Energy’s income statement related to the interest rate swap.

NOTE 12. COMMITMENTS AND CONTINGENCIESFAIR VALUE MEASUREMENTS
NOTE 12(a) Capital Purchase ObligationsFair Value of Financial Instruments - Various contractual obligations contain minimum future commitmentsThe carrying amounts of current assets and current liabilities approximate fair value because of the short maturity of such financial instruments. Carrying amounts and related to capital expenditures for certain construction projects. IPL’s projects include the installationestimated fair values of an SCR system at Ottumwa Unit 1 to reduce NOx emissions at the EGU. WPL’s projects include West Riverside. At September 30, 2017, Alliant Energy’s, IPL’s and WPL’s minimum future commitments related to certain contractual obligations for these projectsother financial instruments were $105 million, $8 million and $97 million, respectively.as follows (in millions):

Alliant EnergyJune 30, 2023December 31, 2022
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Money market fund investments$6 $6 $— $— $6 $10 $10 $— $— $10 
Commodity derivatives147  80 67 147 237 — 206 31 237 
Interest rate derivatives4  4  4 — — — — — 
Deferred proceeds175   175 175 185 — — 185 185 
Liabilities:
Commodity derivatives97  84 13 97 79 — 67 12 79 
Long-term debt (incl. current maturities)8,595  7,950 1 7,951 8,076 — 7,338 7,339 

IPLJune 30, 2023December 31, 2022
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Money market fund investments$6 $6 $— $— $6 $10 $10 $— $— $10 
Commodity derivatives95  44 51 95 138 — 111 27 138 
Deferred proceeds175   175 175 185 — — 185 185 
Liabilities:
Commodity derivatives37  27 10 37 46 — 35 11 46 
Long-term debt3,702  3,321  3,321 3,646 — 3,228 — 3,228 
2421



WPLJune 30, 2023December 31, 2022
Fair ValueFair Value
CarryingLevelLevelLevelCarryingLevelLevelLevel
Amount123TotalAmount123Total
Assets:
Commodity derivatives$52 $— $36 $16 $52 $99 $— $95 $4 $99 
Liabilities:
Commodity derivatives60  57 3 60 33 — 32 33 
Long-term debt3,068  2,875  2,875 2,770 — 2,542 — 2,542 
NOTE 12(b) Other Purchase Obligations - Various commodity supply, transportation and storage contracts help meet obligations to provide electricity and natural gas to utility customers. In addition, there are various purchase obligations associated with other goods and services. At September 30, 2017, minimum future commitments related to these purchase obligations were
Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):
Alliant EnergyCommodity Contract Derivative
Assets and (Liabilities), netDeferred Proceeds
Three Months Ended June 302023202220232022
Beginning balance, April 1($5)$10$153$227
Total net losses included in changes in net assets (realized/unrealized)(7)(10)
Purchases6279
Sales(1)
Settlements (a)5(7)2217
Ending balance, June 30$54$72$175$244
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at June 30($7)($10)$—$—
 Alliant Energy IPL WPL
Purchased power (a)
$1,278
 
$1,194
 
$84
Natural gas847
 422
 425
Coal (b)144
 66
 78
Other (c)34
 25
 1
 
$2,303
 
$1,707
 
$588
Alliant EnergyCommodity Contract Derivative
Assets and (Liabilities), netDeferred Proceeds
Six Months Ended June 302023202220232022
Beginning balance, January 1$19$29$185$214
Total net losses included in changes in net assets (realized/unrealized)(11)(16)
Purchases6279
Sales(1)
Settlements (a)(15)(20)(10)30
Ending balance, June 30$54$72$175$244
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at June 30($11)($16)$—$—

(a)Includes payments required by purchased power agreements for capacity rights and minimum quantities of MWhs required to be purchased.
(b)
Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of September 30, 2017 regarding expected future usage, which is subject to change.
(c)
Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2017.

NOTE 12(c) Legal Proceedings -
Flood Damage Claims - In 2013, several plaintiffs purporting to represent a class of residential and commercial property owners filed a complaint against Cedar Rapids and Iowa City Railway Company (CRANDIC), Alliant Energy and various other defendants in the Iowa District Court for Linn County. Plaintiffs assert claims of negligence and strict liability based on their allegations that CRANDIC (along with other defendants) caused or exacerbated flooding of the Cedar River in June 2008. In February 2016, the Iowa District Court for Linn County ruled in favor of Alliant Energy and CRANDIC and dismissed all claims against them, resulting in no loss. In August 2016, the Iowa District Court for Linn County dismissed all claims against the remaining defendants. In September 2016, plaintiffs filed a notice of appeal with the Supreme Court of Iowa. Alliant Energy does not currently believe any material losses for this complaint are both probable and reasonably estimated, and therefore has not recognized any material loss contingency amounts as of September 30, 2017.

NOTE 12(d) Guarantees and Indemnifications -
RMT - In 2013, Alliant Energy sold RMT. RMT provided renewable energy services, including construction and high voltage connection services for wind and solar projects. As part of the sale, Alliant Energy indemnified the buyer for any claims, including claims of warranty under the project obligations that were commenced or are based on actions that occurred prior to the sale, except for liabilities already accounted for through adjustments to the purchase price. Alliant Energy also guaranteed RMT’s performance obligations related to certain of RMT’s projects that were commenced prior to Alliant Energy’s sale of RMT. In the first quarter of 2017, all warranty periods and performance guarantees expired and all outstanding warranty claims were resolved.

Whiting Petroleum - In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. Whiting Petroleum is an independent oil and gas company. Alliant Energy Resources, LLC, as the successor to a predecessor entity that owned Whiting Petroleum, and a wholly-owned subsidiary of AEF, continues to guarantee the partnership obligations of an affiliate of Whiting Petroleum under general partnership agreements in the oil and gas industry, including with respect to the future abandonment of certain platforms off the coast of California and related onshore plant and equipment owned by the partnerships. The guarantees do not include a maximum limit. As of September 30, 2017, the present value of the abandonment obligations is estimated at $33 million. Alliant Energy is not aware of any material liabilities related to these guarantees of which it is probable that Alliant Energy Resources, LLC will be obligated to pay and therefore has not recognized any material liabilities related to this guarantee as of September 30, 2017.

Non-regulated Wind Investment in Oklahoma - In July 2017, a wholly-owned subsidiary of AEF acquired a cash equity ownership interest in a non-regulated wind farm located in Oklahoma. The wind farm provides electricity to a third-party under a long-term purchased power agreement. Alliant Energy provided a parent guarantee of its subsidiary’s indemnification obligations under the related operating agreement and purchased power agreement. Alliant Energy’s obligations under the operating agreement were $98 million as of September 30, 2017 and will reduce annually until expiring in July 2047. Alliant Energy’s obligations under the purchased power agreement are subject to a maximum limit of $17 million and expire in December 2031, subject to potential extension. Alliant Energy is not aware of any material liabilities related to this guarantee that it is probable that it will be obligated to pay and therefore has not recognized any material

IPLCommodity Contract Derivative
Assets and (Liabilities), netDeferred Proceeds
Three Months Ended June 302023202220232022
Beginning balance, April 1$—$7$153$227
Total net losses included in changes in net assets (realized/unrealized)(13)(3)
Purchases5158
Sales(1)
Settlements (a)4(4)2217
Ending balance, June 30$41$58$175$244
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at June 30($13)($3)$—$—
2522



IPLCommodity Contract Derivative
Assets and (Liabilities), netDeferred Proceeds
Six Months Ended June 302023202220232022
Beginning balance, January 1$16$18$185$214
Total net losses included in changes in net assets (realized/unrealized)(12)(7)
Purchases5158
Sales(1)
Settlements (a)(13)(11)(10)30
Ending balance, June 30$41$58$175$244
The amount of total net losses for the period included in changes in net assets attributable to the change in unrealized losses relating to assets and liabilities held at June 30($12)($8)$—$—
liabilities
WPLCommodity Contract Derivative
Assets and (Liabilities), net
Three Months Ended June 3020232022
Beginning balance, April 1($5)$3
Total net gains (losses) included in changes in net assets (realized/unrealized)6(7)
Purchases1121
Settlements1(3)
Ending balance, June 30$13$14
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30$6($7)
WPLCommodity Contract Derivative
Assets and (Liabilities), net
Six Months Ended June 3020232022
Beginning balance, January 1$3$11
Total net gains (losses) included in changes in net assets (realized/unrealized)1(9)
Purchases1121
Settlements(2)(9)
Ending balance, June 30$13$14
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at June 30$1($8)

(a)Settlements related to this guarantee asdeferred proceeds are due to the change in the carrying amount of September 30, 2017. Refer to Note 5(a)receivables sold less the allowance for further discussion of the non-regulated wind investment.

IPL’s Minnesota Electric Distribution Assets - IPL provided indemnificationsexpected credit losses associated with the July 2015 salereceivables sold and cash amounts received from the receivables sold.

Commodity Contracts - The fair value of its Minnesota electric distributionFTR and natural gas commodity contracts categorized as Level 3 was recognized as net derivative assets for losses resulting from potential breach of IPL’s representations, warranties and obligations under the sale agreement. Alliant Energy and IPL believe the likelihood of having to make any material cash payments under these indemnifications is remote. IPL has not recorded any material liabilities related to these indemnifications as of September 30, 2017. The general terms of the indemnifications provided by IPL included a maximum limit of $17 million and expire in October 2020.

NOTE 12(e) Environmental Matters -
Manufactured Gas Plant (MGP) Sites - IPL and WPL have current or previous ownership interests in various sites that are previously associated with the production of gas for which IPL and WPL have, or may have in the future, liability for investigation, remediation and monitoring costs. IPL and WPL are working pursuant to the requirements of various federal and state agencies to investigate, mitigate, prevent and remediate, where necessary, the environmental impacts to property, including natural resources, at and around these former MGP sites in order to protect public health and the environment.

Environmental liabilities related to the MGP sites are recorded based upon periodic studies. Such amounts are based on the best current estimate of the remaining amount to be incurred for investigation, remediation and monitoring costs for those sites where the investigation process has been or is substantially completed, and the minimum of the estimated cost range for those sites where the investigation is in its earlier stages. There are inherent uncertainties associated with the estimated remaining costs for MGP projects primarily due to unknown site conditions and potential changes in regulatory agency requirements. It is possible that future cost estimates will be greater than current estimates as the investigation process proceeds and as additional facts become known. Costs of future expenditures for environmental remediation obligations are not discounted. At September 30, 2017, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were(liabilities) as follows (in millions). At September 30, 2017, such amounts for WPL were not material.:
Alliant EnergyIPLWPL
Excluding FTRsFTRsExcluding FTRsFTRsExcluding FTRsFTRs
June 30, 2023($8)$62($5)$46($3)$16
December 31, 2022(10)29(9)25(1)4

 Alliant Energy IPL
Range of estimated future costs
$12
-$31 
$10
-$27
Current and non-current environmental liabilities16 14

WPL Consent Decree - In 2013, the U.S. District Court for the Western District of Wisconsin approved a Consent Decree that WPL, along with the other owners of Edgewater and Columbia, entered into with the EPA and the Sierra Club, thereby resolving claims against WPL. Such claims included allegations that the owners of Edgewater, Nelson Dewey and Columbia violated the Prevention of Significant Deterioration program requirements, Title V Operating Permit requirements of the Clean Air Act (CAA) and the Wisconsin State Implementation Plan designed to implement the CAA.

WPL has completed various requirements under the Consent Decree. WPL’s remaining requirements include installing an SCR system at Columbia Unit 2 and fuel switching or retiring Edgewater Unit 4 by December 31, 2018. The Consent Decree also establishes SO2, NOx and particulate matter emission rate limits for Columbia Units 1 and 2, and Edgewater Units 4 and 5. In addition, the Consent Decree includes annual plant-wide SO2 and NOx emission caps for Columbia and Edgewater. WPL is also in the process of completing approximately $7 million in environmental mitigation projects. Alliant Energy and WPL currently expect to recover material costs incurred by WPL related to compliance with the terms of the Consent Decree from WPL’s electric customers.

IPL Consent Decree - In 2015, the U.S. District Court for the Northern District of Iowa approved a Consent Decree that IPL entered into with the EPA, the Sierra Club, the State of Iowa and Linn County in Iowa, thereby resolving potential CAA issues associated with emissions from IPL’s coal-fired generating facilities in Iowa. IPL has completed various requirements under the Consent Decree. IPL’s remaining requirements include installing an SCR system or equivalent NOx reduction system at Ottumwa by December 31, 2019; fuel switching or retiring Prairie Creek Unit 4 by June 1, 2018, Burlington by December 31, 2021 and Prairie Creek Units 1 and 3 by December 31, 2025.

The Consent Decree also establishes SO2, NOx and particulate matter emission rate limits with varying averaging times for Burlington, Lansing, M.L. Kapp, Ottumwa and Prairie Creek. In addition, the Consent Decree includes calendar-year SO2 and NOx emission caps for Prairie Creek, and calendar-year SO2 and NOx emission caps in aggregate for Burlington, Dubuque, Lansing, M.L. Kapp, Ottumwa, Prairie Creek and Sutherland. IPL is also in the process of completing approximately $6 million in environmental mitigation projects. Alliant Energy and IPL currently expect to recover material

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costs incurred by IPL related to the environmental control systems and environmental mitigation projects from IPL’s electric customers.

Other Environmental Contingencies - In addition to the environmental liabilities discussed above, various environmental rules are monitored that may have a significant impact on future operations. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Given uncertainties regarding the outcome, timing and compliance plans for these environmental matters, the complete financial impact of each of these rules is not able to be determined; however future capital investments and/or modifications to EGUs to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Cross-State Air Pollution Rule, Effluent Limitation Guidelines, Coal Combustion Residuals Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including carbon emissions from new (CAA Section 111(b)) and existing (CAA Section 111(d)) fossil-fueled EGUs.

NOTE 13. SEGMENTS OF BUSINESSCOMMITMENTS AND CONTINGENCIES
Alliant EnergyNOTE 13(a) Capital Purchase Commitments - Certain financial information relatingVarious contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects, including IPL’s and WPL’s expansion of solar generation. At June 30, 2023, Alliant Energy’s, business segments is as follows. Intersegment revenuesIPL’s and WPL’s minimum future commitments for these projects were not material to Alliant Energy’s operations. Refer to Note 5(a) for discussion of Alliant Energy’s acquisition of an interest in a non-regulated wind farm in Oklahoma in July 2017, which increased the assets for “Non-Regulated, Parent$188 million, $87 million and Other.” Refer to Note 3 for discussion of asset valuation charges recorded in the third quarter of 2016 related to the Franklin County wind farm.$101 million, respectively.
 Utility (a) Non-Regulated, Alliant Energy
 Electric Gas Other Total Parent and Other Consolidated
 (in millions)
Three Months Ended September 30, 2017           
Operating revenues
$840.6
 
$45.8
 
$11.2
 
$897.6
 
$9.3
 
$906.9
Operating income (loss)232.6
 (2.4) (7.7) 222.5
 9.0
 231.5
Net income (loss) attributable to Alliant Energy common shareowners      176.3
 (7.5) 168.8
Three Months Ended September 30, 2016           
Operating revenues
$864.3
 
$39.5
 
$9.4
 
$913.2
 
$11.4
 
$924.6
Operating income (loss)244.2
 (3.7) 0.4
 240.9
 (78.3) 162.6
Amounts attributable to Alliant Energy common shareowners:           
Income (loss) from continuing operations, net of tax      183.1
 (54.3) 128.8
Loss from discontinued operations, net of tax      
 (0.4) (0.4)
Net income (loss)      183.1
 (54.7) 128.4
 Utility (a) Non-Regulated, Alliant Energy
 Electric Gas Other Total Parent and Other Consolidated
 (in millions)
Nine Months Ended September 30, 2017           
Operating revenues
$2,199.1
 
$262.7
 
$34.4
 
$2,496.2
 
$29.9
 
$2,526.1
Operating income (loss)475.4
 29.5
 (6.8) 498.1
 25.6
 523.7
Amounts attributable to Alliant Energy common shareowners:           
Income from continuing operations, net of tax      353.5
 8.6
 362.1
Income from discontinued operations, net of tax      
 1.4
 1.4
Net income      353.5
 10.0
 363.5
Nine Months Ended September 30, 2016           
Operating revenues
$2,209.1
 
$248.7
 
$35.0
 
$2,492.8
 
$30.2
 
$2,523.0
Operating income (loss)473.3
 27.0
 4.4
 504.7
 (67.6) 437.1
Amounts attributable to Alliant Energy common shareowners:           
Income (loss) from continuing operations, net of tax      350.3
 (39.5) 310.8
Loss from discontinued operations, net of tax      
 (2.0) (2.0)
Net income (loss)      350.3
 (41.5) 308.8



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(a)Alliant Energy’s utility business segments include: a) utility electric operations, which include Alliant Energy’s entire investment in ATC; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business.

IPLNOTE 13(b) Other Purchase Commitments - Certain financial information relatingVarious commodity supply, transportation and storage contracts help meet obligations to IPL’s business segments is as follows. Intersegment revenues were not materialprovide electricity and natural gas to IPL’s operations.
 Electric Gas Other Total
 (in millions)
Three Months Ended September 30, 2017       
Operating revenues
$489.0
 
$27.4
 
$11.0
 
$527.4
Operating income (loss)138.3
 (2.1) (4.4) 131.8
Earnings available for common stock      120.4
Three Months Ended September 30, 2016       
Operating revenues
$483.2
 
$23.9
 
$9.1
 
$516.2
Operating income (loss)125.9
 (1.4) 1.4
 125.9
Earnings available for common stock      114.1
Nine Months Ended September 30, 2017       
Operating revenues
$1,217.6
 
$147.2
 
$33.3
 
$1,398.1
Operating income (loss)234.5
 14.7
 (1.5) 247.7
Earnings available for common stock      200.4
Nine Months Ended September 30, 2016       
Operating revenues
$1,209.2
 
$142.6
 
$34.1
 
$1,385.9
Operating income213.8
 15.3
 6.8
 235.9
Earnings available for common stock      191.6

WPL - Certain financial information relating to WPL’s business segments is as follows. Intersegment revenues were not material to WPL’s operations.
 Electric Gas Other Total
 (in millions)
Three Months Ended September 30, 2017       
Operating revenues
$351.6
 
$18.4
 
$0.2
 
$370.2
Operating income (loss)94.3
 (0.3) (3.3) 90.7
Earnings available for common stock      49.8
Three Months Ended September 30, 2016       
Operating revenues
$381.1
 
$15.6
 
$0.3
 
$397.0
Operating income (loss)118.3
 (2.3) (1.0) 115.0
Earnings available for common stock      69.0
Nine Months Ended September 30, 2017       
Operating revenues
$981.5
 
$115.5
 
$1.1
 
$1,098.1
Operating income (loss)240.9
 14.8
 (5.3) 250.4
Earnings available for common stock      133.4
Nine Months Ended September 30, 2016       
Operating revenues
$999.9
 
$106.1
 
$0.9
 
$1,106.9
Operating income (loss)259.5
 11.7
 (2.4) 268.8
Earnings available for common stock      158.7

NOTE 14. RELATED PARTIES
Service Agreements - Pursuant to service agreements, IPL and WPL receiveutility customers. In addition, there are various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation and benefits, feespurchase commitments associated with various professional services, depreciationother goods and amortization of property, plant and equipment, and a return on net assets. Corporate Services also acts as agent on behalf of IPL and WPL pursuant to the service agreements. As agent, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions within MISO. Corporate Services assigns such sales and purchases among IPL and WPL based on statements received from MISO. The amounts billed for services provided, sales credited and purchases for the three and nine months ended Septemberservices. At June 30, 2023, related minimum future commitments were as follows (in millions):

Alliant EnergyIPLWPL
Natural gas$1,083$494$589
Coal1637984
Other (a)1065125
$1,352$624$698

(a)Includes individual commitments incurred during the normal course of business that exceeded $1 million at June 30, 2023.

NOTE 13(c) Guarantees and Indemnifications -
Whiting Petroleum - Whiting Petroleum is an independent oil and gas company. In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. Alliant Energy Resources, LLC, as the successor to a predecessor entity that owned Whiting Petroleum, and a wholly-owned subsidiary of AEF, continues to guarantee the partnership obligations of an affiliate of Whiting Petroleum under multiple general partnership agreements in the oil and gas industry. The guarantees do not include a maximum limit. Based on information made available to Alliant Energy by Whiting Petroleum, the Whiting Petroleum affiliate holds an approximate 6% share in the partnerships, and currently known obligations include costs associated with the future abandonment of certain facilities owned by the partnerships. The general partnerships were formed under California law, and Alliant Energy Resources, LLC may need to perform under the guarantees if the affiliate of Whiting Petroleum is unable to meet its partnership obligations.

As of June 30, 2023, the currently known partnership obligations for the abandonment obligations are estimated at $58 million, which represents Alliant Energy’s currently estimated maximum exposure under the guarantees. Alliant Energy estimates its expected loss to be a portion of the $58 million of known partnership abandonment obligations of the Whiting Petroleum affiliate and the other partners. Alliant Energy is not aware of any material liabilities related to these guarantees that it is probable that it will be obligated to pay; however, as of both June 30, 2023 and December 31, 2022, a liability of $5 million is recorded in “Other liabilities” on Alliant Energy’s balance sheets for expected credit losses related to the contingent obligations that are in the scope of these guarantees.

Whiting Petroleum completed a business combination with Oasis Petroleum Inc. in July 2022. The combined operations are now known as Chord Energy Corporation. The business combination is not expected to affect the scope of the Whiting Petroleum affiliate’s obligations to Alliant Energy or Alliant Energy’s related guarantees.

Non-utility Wind Farm in Oklahoma - In 2017, a wholly-owned subsidiary of AEF acquired a cash equity ownership interest in a non-utility wind farm located in Oklahoma. The wind farm provides electricity to a third party under a long-term PPA. Alliant Energy provided a parent guarantee of its subsidiary’s indemnification obligations under the related operating agreement and PPA. Alliant Energy’s obligations under the operating agreement were $59 million as of June 30, 2023 and will reduce annually until expiring in July 2047. Alliant Energy’s obligations under the PPA are subject to a maximum limit of $17 million and expire in December 2031, subject to potential extension. Alliant Energy is not aware of any material liabilities related to this guarantee that it is probable that it will be obligated to pay and therefore has not recognized any material liabilities related to this guarantee as of June 30, 2023 and December 31, 2022.

NOTE 13(d) Environmental Matters -
Manufactured Gas Plant (MGP) Sites - IPL and WPL have current or previous ownership interests in various sites that are previously associated with the production of gas for which IPL and WPL have, or may have in the future, liability for investigation, remediation and monitoring costs. IPL and WPL are working pursuant to the requirements of various federal and state agencies to investigate, mitigate, prevent and remediate, where necessary, the environmental impacts to property, including natural resources, at and around these former MGP sites in order to protect public health and the environment. At June 30, 2023, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, which are not discounted, were as follows (in millions):
Alliant EnergyIPLWPL
Range of estimated future costs$9 -$36$5 -$11$4 -$25
Current and non-current environmental liabilities$18$8$10

IPL Consent Decree - In 2015, the U.S. District Court for the Northern District of Iowa approved a Consent Decree that IPL entered into with the EPA, the Sierra Club, the State of Iowa and Linn County in Iowa, thereby resolving potential Clean Air Act issues associated with emissions from IPL’s coal-fired generating facilities in Iowa. IPL has completed various requirements under the Consent Decree. IPL’s remaining requirements include fuel switching or retiring Prairie Creek Units 1 and 3 by December 31, 2025. Alliant Energy and IPL currently expect to recover material costs incurred by IPL related to compliance with the terms of the Consent Decree from IPL’s electric customers.
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Other Environmental Contingencies - In addition to the environmental liabilities discussed above, various environmental rules are monitored that may have a significant impact on future operations. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Given uncertainties regarding the outcome, timing and compliance plans for these environmental matters, the complete financial impact of each of these rules is not able to be determined; however, future capital investments and/or modifications to EGUs and electric and gas distribution systems to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Cross-State Air Pollution Rule, Effluent Limitation Guidelines, Coal Combustion Residuals Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including the Clean Air Act.
 IPL WPL
 Three Months Nine Months Three Months Nine Months
 2017 2016 2017 2016 2017 2016 2017 2016
Corporate Services billings
$48
 
$41
 
$130
 
$124
 
$37
 
$33
 
$100
 
$103
Sales credited8
 4
 15
 7
 6
 3
 8
 6
Purchases billed109
 126
 271
 324
 32
 23
 99
 65


Net intercompany payablesNOTE 13(e) MISO Transmission Owner Return on Equity Complaints - A group of stakeholders, including MISO cooperative and municipal utilities, previously filed complaints with the Federal Energy Regulatory Commission (FERC) requesting a reduction to Corporate Services were as follows (in millions):
 IPL WPL
 September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016
Net payables to Corporate Services$118 $104 $64 $72

ATCthe base return on equity authorized for MISO transmission owners, including ITC Midwest LLC - Pursuant and ATC. In 2019, FERC issued an order on the previously filed complaints and reduced the base return on equity authorized for the MISO transmission owners to 9.88% for November 12, 2013 through February 11, 2015, and subsequent to September 28, 2016. In 2020, FERC issued orders in response to various agreements, WPL receives a range of transmission services from ATC LLC. WPL provides operation, maintenance,rehearing requests and construction services to ATC LLC. WPL and ATC LLC also bill each other for use of shared facilities owned by each party. The related amounts billed betweenincreased the partiesbase return on equity authorized for the threeMISO transmission owners from 9.88% to 10.02% for November 12, 2013 through February 11, 2015, and nine months endedsubsequent to September 30 were as follows (in millions):28, 2016. In August 2022, the U.S. Court of Appeals for the District of Columbia Circuit vacated FERC’s prior orders that established the base return on equity authorized for the MISO transmission owners and remanded the cases to FERC for further proceedings, which may result in additional changes to the base return on equity authorized for the MISO transmission owners. Any further changes in FERC’s decisions may have an impact on Alliant Energy’s share of ATC’s future earnings and customer costs.

 Three Months Nine Months
 2017 2016 2017 2016
ATC LLC billings to WPL
$26
 
$28
 
$79
 
$82
WPL billings to ATC LLC2
 4
 8
 10

WPL owed ATC LLC net amounts of $8 million as of September 30, 2017 and $8 million as of December 31, 2016.

Refer to Note 5(a) for discussion of WPL’s transfer of its investment in ATC LLC to ATI on December 31, 2016.

Franklin County Wind Farm - Refer to Note 3 for discussion of the transfer of the Franklin County wind farm from AEF to IPL in April 2017.

NOTE 14. SEGMENTS OF BUSINESS
Certain financial information relating to Alliant Energy’s, IPL’s and WPL’s business segments is as follows. Intersegment revenues were not material to their respective operations.
Alliant EnergyATC Holdings,Alliant
UtilityNon-Utility,Energy
ElectricGasOtherTotalParent and OtherConsolidated
(in millions)
Three Months Ended June 30, 2023
Revenues$799$77$13$889$23$912
Operating income200272098217
Net income (loss) attributable to Alliant Energy common shareowners161(1)160
Three Months Ended June 30, 2022
Revenues$812$94$13$919$24$943
Operating income195812048212
Net income attributable to Alliant Energy common shareowners1509159
Alliant EnergyATC Holdings,Alliant
UtilityNon-Utility,Energy
ElectricGasOtherTotalParent and OtherConsolidated
(in millions)
Six Months Ended June 30, 2023
Revenues$1,567$353$25$1,945$45$1,990
Operating income363521142613439
Net income attributable to Alliant Energy common shareowners3212323
Six Months Ended June 30, 2022
Revenues$1,586$356$23$1,965$47$2,012
Operating income37665444515460
Net income attributable to Alliant Energy common shareowners32922351
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IPLElectricGasOtherTotal
(in millions)
Three Months Ended June 30, 2023
Revenues$431$44$12$487
Operating income1055110
Net income89
Three Months Ended June 30, 2022
Revenues$442$52$12$506
Operating income10441109
Net income87
Six Months Ended June 30, 2023
Revenues$819$194$24$1,037
Operating income171278206
Net income161
Six Months Ended June 30, 2022
Revenues$843$191$22$1,056
Operating income179363218
Net income173
WPLElectricGasOtherTotal
(in millions)
Three Months Ended June 30, 2023
Revenues$368$33$1$402
Operating income952299
Net income72
Three Months Ended June 30, 2022
Revenues$370$42$1$413
Operating income91495
Net income63
Six Months Ended June 30, 2023
Revenues$748$159$1$908
Operating income192253220
Net income160
Six Months Ended June 30, 2022
Revenues$743$165$1$909
Operating income197291227
Net income156

NOTE 15. RELATED PARTIES
Service Agreements - Pursuant to service agreements, IPL and WPL receive various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation and benefits, fees associated with various professional services, depreciation and amortization of property, plant and equipment, and a return on net assets. Corporate Services also acts as agent on behalf of IPL and WPL pursuant to the service agreements. As agent, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions within MISO. Corporate Services assigns such sales and purchases among IPL and WPL based on statements received from MISO. The amounts billed for services provided, sales credited and purchases for the three and six months ended June 30 were as follows (in millions):
IPLWPL
Three MonthsSix MonthsThree MonthsSix Months
20232022202320222023202220232022
Corporate Services billings$48$51$88$91$43$42$80$78
Sales credited1810132231
Purchases billed941291872232391761

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Net intercompany payables to Corporate Services were as follows (in millions):
IPLWPL
June 30, 2023December 31, 2022June 30, 2023December 31, 2022
Net payables to Corporate Services$116$103$73$56

ATC - Pursuant to various agreements, WPL receives a range of transmission services from ATC. WPL provides operation, maintenance, and construction services to ATC. WPL and ATC also bill each other for use of shared facilities owned by each party. The related amounts billed between the parties for the three and six months ended June 30 were as follows (in millions):
Three MonthsSix Months
2023202220232022
ATC billings to WPL$44$35$78$69
WPL billings to ATC55118

WPL owed ATC net amounts of $10 million as of June 30, 2023 and $10 million as of December 31, 2022.

ITEM 2. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS


This MDA includes information relating to Alliant Energy, and IPL and WPL (collectively, the Utilities), as well as ATC Holdings, AEF and Corporate Services. Where appropriate, information relating to a specific entity has been segregated and labeled as such. The following discussion and analysis should be read in conjunction with the Financial Statements and the Notes included in this report, as well as the financial statements, notes and MDA included in the 20162022 Form 10-K.10-K. Unless otherwise noted, all “per share” references in MDA refer to earnings per diluted share.


EXECUTIVE OVERVIEW2023 HIGHLIGHTS


Description of Business
General - Alliant Energy is a Midwest U.S. energy holding company whose primary subsidiaries are IPL, WPL, AEF and Corporate Services. IPL and WPL are public utilities, and AEF is the parent company for Alliant Energy’s non-regulated businesses and holds all of Alliant Energy’s investment in ATC. Corporate Services provides administrative services to Alliant Energy and its subsidiaries. An illustration of Alliant Energy’s primary businesses is shown below.
Alliant Energy
Utilities, ATC Investment and Corporate ServicesNon-regulated and Parent
 - Retail electric and gas services in IA (IPL) - Transportation (AEF)
 - Retail electric and gas services in WI (WPL) - Non-regulated wind investment (AEF)
 - ATC Investment (ATI) - Sheboygan Falls Energy Facility (AEF)
 - Wholesale electric service in MN, IL & IA (IPL) - Parent Company
 - Wholesale electric service in WI (WPL)
 - Corporate Services


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Financial Results - Alliant Energy’s net income and EPS attributable to Alliant Energy common shareowners for the third quarter were as follows (dollars in millions, except per share amounts):
 2017 2016
 Income (Loss) EPS Income (Loss) EPS
Continuing operations:       
Utilities, ATC Investment and Corporate Services
$179.7
 
$0.78
 
$186.7
 
$0.82
Non-regulated and Parent(10.9) (0.05) (57.9) (0.25)
Income from continuing operations168.8
 0.73
 128.8
 0.57
Loss from discontinued operations
 
 (0.4) 
Net income
$168.8
 
$0.73
 
$128.4
 
$0.57

The table above includes EPS from continuing operations for utilities, ATC Investment and Corporate Services, and non-regulated and parent, which are non-GAAP financial measures. Alliant Energy believes these non-GAAP financial measures are useful to investors because they facilitate an understanding of segment performance and trends and provide additional information about Alliant Energy’s operations on a basis consistent with the measures that management uses to manage its operations and evaluate its performance.

Alliant Energy’s, IPL’s and WPL’s income from continuing operations increased (decreased) by $40 million, $6 million and ($19) million, respectively, for the three-month period. Alliant Energy’s increase was primarily due to asset valuation charges at AEF related to the Franklin County wind farm in the third quarter of 2016, higher revenues resulting from IPL’s interim retail electric base rate increase implemented in April 2017 and WPL’s retail electric and gas base rate increases implemented in January 2017, partially offset by estimated temperature impacts on IPL’s and WPL’s retail electric and gas sales, higher depreciation expense, higher energy efficiency cost recovery amortization at WPL, and lower AFUDC at IPL. WPL’s decrease was also impacted by reduced equity income resulting from the transfer of WPL’s investment in ATC LLC to ATI on December 31, 2016.

Refer to “Results of Operations” for additional details regarding the various factors impacting earnings during the third quarters of 2017 and 2016.

2017 Overview - Alliant Energy, IPL and WPL continue to focus on achieving their financial objectives and executing their strategic plan. Key developmentshighlights since the filing of the 2016 2022 Form 10-K include the following:
Marshalltown Generating Station - IPL’s construction of Marshalltown, an approximate 660 MW natural gas-fired combined-cycle EGU, was completed in April 2017. Final capital expenditures are currently estimated to be approximately $645 million to construct the EGU and a pipeline to supply natural gas to the EGU, excluding transmission network upgrades and AFUDC.

Customer Investments:
Franklin County Wind Farm -In April 2017, the 99 MW Franklin County wind farm was transferred from AEF to IPL.
IPL’s and WPL’s Potential Expansion of Wind Generation - In addition to IPL’s 500 MW expansion of wind generation approved by the IUB in October 2016 and transfer of the 99 MW Franklin County wind farm to IPL in 2017, IPL and WPL are currently exploring options to own and operate up to 500 MW and 200 MW, respectively, of additional new wind generation. In August 2017,2021, IPL filed an application with the IUB for advance rate-making principles for the up to 500 MW of the additional wind generation. In the fourth quarter of 2017, WPL expects to file for approval from the PSCW and FERC for the acquisition of 55 MW of the Forward Wind Energy Center, and plans to file for authority for the remaining up to 200 MW of new wind generation. Refer to “Strategic Overview” for further discussion. The amount and timing of these wind projects will largely depend on regulatory approvals and the acquisition of wind sites.
WPL’s Construction of West Riverside - In October 2017, WPL received an order from the PSCW authorizing various electric cooperatives, which currently have wholesale power supply agreements with WPL, to acquire approximately 65 MW of West Riverside while the EGU is being constructed. As part of the electric cooperatives’ acquisitions, which are currently expected to be completed in the fourth quarter of 2017, the current wholesale power supply agreements with the various electric cooperatives will be extended by at least four years until 2026 with automatic continuation of such agreements unless terminated by either party, with a five-year notice requirement.
Non-regulated Wind Investment in Oklahoma - In July 2017, a wholly-owned subsidiary of AEF acquired a 50% cash equity ownership interest in a 225 MW non-regulated wind farm located in Oklahoma. Refer to Note 5(a) for further discussion.
IPL’s Retail Electric Rate Review (2016 Test Year) - In April 2017, IPL filed a request with the IUB for up to increase annual electric base rates400 MW of solar generation and 75 MW of battery storage. In April 2023, the IUB approved advance rate-making principles for its Iowaup to 200 MW of solar generation. The IUB’s order included a cost target of $1,575/kilowatt, including AFUDC and transmission upgrade costs among other costs. Any reasonable and prudent costs incurred in excess of the cost target, as well as the related return on common equity, would need to be addressed in future IPL retail electric customers. The request was based on a 2016 historical Test Year as adjustedrate review filings. In May 2023, IPL requested reconsideration of certain ratemaking principles for certain known and measurable changes occurringthe up to 12 months after200 MW of solar generation, including the commencementcost target and return on common equity. In June 2023, IPL and the IUB filed a joint motion for remand of the proceeding. The key driversother 200 MW of solar generation and 75 MW of battery storage for further reconsideration by the IUB, which was granted by the court. In June 2023, the IUB granted reconsideration of advance rate-making principles for the filing included recovery400 MW of capital projects, primarily power grid modernizationsolar generation and investments that

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advance cleaner energy, including Marshalltown. An interim retail electric base rate increase of $102 million, or approximately 7%, on an annual basis, was implemented effective April 13, 2017.battery storage. In September 2017,August 2023, IPL reached a partial, non-unanimous settlement agreement with the Iowa Office of Consumer Advocate, the Iowa Business Energy Coalition and the Large Energy Group to increase annual retail electric base rates by $130 million, or approximately 9%, subject to IUB approval. Asapproval, for up to 400 MW of solar generation with a resultcost target of $735 million, including AFUDC and transmission upgrade costs, and a related return on common equity of 10.75%.
In June 2023, WPL received an oral decision from the proposed settlement,PSCW authorizing WPL to construct, own and operate 175 MW of battery storage, with 100 MW and 75 MW at the Grant County and Wood County solar projects, respectively. A written order from the PSCW is currently expected in the third quarter of 2017, IPL recorded a write-down of regulatory assets of $9 million. IPL currently expects to implement final rates in the first quarter of 2018.2023.
WPL’s Retail Fuel-related Rate Filing (2018 Test Year) - In July 2017,June 2023, WPL filed a requestrequests with the PSCW for approval to construct improvements at the natural gas-fired Neenah Energy Facility and Sheboygan Falls Energy Facility, which would increase annual rates for WPL’s retail electric customers by $6 million, or approximately 1%, in 2018. The increase primarily reflects a change in expected fuel-related costs in 2018, which are expected to be offset by $3 million of over-collections from WPL’s 2016 fuel-related costs. Any rate changes granted from this request are expected to be effective January 1, 2018.
MISO Transmission Owner Return on Equity Complaints - A group of MISO cooperativethe capacity and municipal utilities previously filed two complaints with FERC requesting a reduction to the base return on equity used by MISO transmission owners, including ITC and ATC LLC, to determine electric transmission costs billed to utilities, including IPL and WPL. In September 2016, FERC issued an order on the first complaint and established a base return on equity of 10.32%, excluding any incentive adders granted by FERC, effective September 28, 2016, and for the refund period from November 12, 2013 through February 11, 2015 (first complaint period). During the nine months ended September 30, 2017, Alliant Energy, IPL and WPL received the refunds for the first complaint period of $50 million, $39 million and $11 million, respectively, after final true-ups. Pursuant to IUB approval, IPL’s retail portionefficiency of the refund from ITC is currently being refunded to its retail customers in 2017. WPL’s retail portion of the refund from ATC LLC will remain in a regulatory liability until such refundsEGUs. Estimated construction costs for these projects are approved to be returned to retail customers in a future rate proceeding.
Credit Facility Agreement - In August 2017, Alliant Energy, IPL and WPL entered into a single new credit facility agreement, which expires in August 2022. The new credit facility agreement includes financial covenants similar to those that were included in the previous credit facility agreements. Asanticipated construction and acquisition expenditures included in “Liquidity and Capital Resources” in the 2022 Form 10-K.
In March 2023, the IUB issued a certificate of September 30, 2017, the short-term borrowing capacity totaled $1 billion ($300 million for Alliant Energypublic convenience, use and necessity (GCU Certificate) granting IPL approval to construct, own and operate up to 50 MW of solar generation and up to 25 MW of battery storage at the parent company level, $300 million forCreston project in Union County, Iowa.
In April 2023, the IUB issued a GCU Certificate granting IPL approval to construct, own and $400 million for WPL).
At-the-Market Offering Program - In the second quarter of 2017, Alliant Energy issued 3.1 million shares of common stock through an at-the-market offering program and received cash proceeds of $124 million, net of $1 million in commissions and fees. The proceeds from the issuances of common stock were used for general corporate purposes.

Future Developments - The following includes key items expected to impact Alliant Energy, IPL and WPL in the future that have been identified since the filing of the 2016 Form 10-K:

2018 Forecast - In 2018, the following financing activities, and impacts to results of operations, are currently anticipated to occur:
Financing Plans - Alliant Energy currently expects to issueoperate up to $200 million150 MW of common stock in 2018 through one or more offeringssolar generation and its Shareowner Direct Plan. IPL currently expects to issue up to $700 million75 MW of long-term debt securitiesbattery storage at the Wever project in 2018, of which $350 million would be used to retire maturing long-term debt in 2018. AEF currently expects to issue up to $1.0 billion of long-term debt in 2018, of which $595 million would be used to refinance term loans.
Lee County, Iowa.
Common Stock Dividends - Alliant Energy announced a 6% increase in its targeted 2018 annual common stock dividend to $1.34 per share, which is equivalent to a quarterly rate of $0.335 per share, beginning with the February 2018 dividend payment. The timing and amount of future dividends is subject to an approved dividend declaration from Alliant Energy’s Board of Directors, and is dependent upon earnings expectations, capital requirements, and general financial business conditions, among other factors.
Utility Electric and Gas Margins - Alliant Energy and IPL currently expect an increase in electric and gas margins in 2018 compared to 2017 as a result of base rate increases in effect from IPL’s retail electric rate review (2016 Test Year) and IPL’s planned retail gas rate review (2017 Test Year). Refer to “Rate Matters” for further discussion of these rate reviews, as well as “Other Future Considerations” for discussion of expected changes in Alliant Energy’s, IPL’s and WPL’s electric transmission service expense in 2018 compared to 2017.
Depreciation and Amortization Expenses - Alliant Energy and IPL currently expect an increase in depreciation and amortization expenses in 2018 compared to 2017 due to property additions, and the implementation of updated depreciation rates for IPL as a result of a recently completed depreciation study, which is expected to be effective with the implementation of final rates from IPL’s retail electric rate review (2016 Test Year).
Interest Expense - Alliant Energy currently expects interest expense to increase in 2018 compared to 2017 due to financings completed in 2017 and planned in 2018 as discussed above.
AFUDC - Alliant Energy currently expects AFUDC to increase in 2018 compared to 2017 primarily due to increased construction work in progress balances related to IPL’s expansion of wind generation and WPL’s West Riverside facility.


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Rate Matters:

In April 2023, WPL filed a retail electric and gas rate review with the PSCW for the 2024/2025 forward-looking Test Period. The key drivers for the filing include revenue requirement impacts of increasing electric and gas rate base, including investments in solar generation and battery storage. The filing requested approval for WPL to implement increases in annual rates for its retail electric and gas customers of $111 million and $17 million in 2024, respectively, with any granted rate changes expected to be effective on January 1, 2024. WPL’s filing also requested approval to implement an additional $71 million increase in annual rates for its retail electric customers in 2025, with any granted rate changes expected to be effective on January 1, 2025. WPL also requested to maintain its current authorized return on common equity of 10% and implement an approximate 56% common equity component of its regulatory capital structure, as well as receive continued recovery of and a return on the remaining net book value of Edgewater Unit 5, which is currently expected to be retired by June 1, 2025. A decision from the PSCW is expected by the end of 2023.
IPL currently expects to file a retail electric and gas rate review with the IUB in the third quarter of 2023. The key drivers for the anticipated filing include revenue requirement impacts of increasing electric and gas rate base, including investments in solar generation.

RESULTS OF OPERATIONS

Overview - Executive Overview” provides an overview of Alliant Energy’s, IPL’s and WPL’s earnings for the three months ended September 30, 2017 and 2016. Additional earnings details for the three and nine months ended September 30, 2017 and 2016 are discussed below.


Results of operations include financial information prepared in accordance with GAAP as well as utility electric margins and utility gas margins, which are not measures of financial performance under GAAP. Utility electric margins are defined as electric operating revenues less electric production fuel, purchased power and electric transmission service expenses. Utility gas margins are defined as gas operating revenues less cost of gas sold. Utility electric margins and utility gas margins are non-GAAP financial measures because they exclude other utility and non-regulated operatingnon-utility revenues, other operation and maintenance expenses, depreciation and amortization expenses, and taxes other than income tax expense.


Management believes that utility electric and gas margins provide a meaningful basis for evaluating and managing utility operations since electric production fuel, purchased power and electric transmission service expenses and cost of gas sold are generally passed through to customers, and therefore, result in changes to electric and gas operating revenues that are comparable to changes in such expenses. The presentation of utility electric and gas margins herein is intended to provide supplemental information for investors regarding operating performance. These utility electric and gas margins may not be comparable to how other entities define utility electric and gas margin. Furthermore, these measures are not intended to replace operating income as determined in accordance with GAAP as an indicator of operating performance.


Additionally, the table below includes EPS for Utilities and Corporate Services, ATC Holdings, and Non-utility and Parent, which are non-GAAP financial measures. Alliant Energy believes these non-GAAP financial measures are useful to investors because they facilitate an understanding of segment performance and trends, and provide additional information about Alliant Energy’s operations on a basis consistent with the measures that management uses to manage its operations and evaluate its performance.

Financial Results Overview - Alliant Energy’s net income and EPS attributable to Alliant Energy common shareowners for the three months ended June 30 were as follows (dollars in millions, except per share amounts):
20232022
Income (Loss)EPSIncome (Loss)EPS
Utilities and Corporate Services$164$0.65$154$0.61
ATC Holdings80.0380.03
Non-utility and Parent(12)(0.04)(3)(0.01)
Alliant Energy Consolidated$160$0.64$159$0.63

Alliant Energy’s Utilities and Corporate Services net income increased by $10 million for the three-month period, primarily due to higher revenue requirements and AFUDC from WPL’s capital investments, and lower electric fuel-related costs, net of recoveries at WPL. These items were partially offset by lower retail electric and gas sales due to the impact of temperatures on customer demand and higher interest expense.

Alliant Energy’s Non-utility and Parent net income decreased by $9 million for the three-month period, primarily due to higher interest expense.

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For the three and ninesix months ended SeptemberJune 30, operating income and a reconciliation of utility electric and gas margins to the most directly comparable GAAP measure, operating income, was as follows (in millions):
Alliant EnergyIPLWPL
Three Months202320222023202220232022
Operating income$217$212$110$109$99$95
Electric utility revenues$799$812$431$442$368$370
Electric production fuel and purchased power expenses(166)(191)(66)(83)(99)(108)
Electric transmission service expense(138)(133)(96)(91)(42)(41)
Utility Electric Margin (non-GAAP)495488269268227221
Gas utility revenues779444523342
Cost of gas sold expense(33)(48)(20)(27)(13)(21)
Utility Gas Margin (non-GAAP)444624252021
Other utility revenues1313121211
Non-utility revenues2324
Other operation and maintenance expenses(163)(166)(85)(87)(67)(67)
Depreciation and amortization expenses(167)(166)(96)(95)(69)(69)
Taxes other than income taxes expense(28)(27)(14)(14)(13)(12)
Operating income$217$212$110$109$99$95
 Alliant Energy IPL WPL
 Three Months Nine Months Three Months Nine Months Three Months Nine Months
 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016
Operating income
$231.5
 
$162.6
 
$523.7
 
$437.1
 
$131.8
 
$125.9
 
$247.7
 
$235.9
 
$90.7
 
$115.0
 
$250.4
 
$268.8
Alliant EnergyIPLWPL
Six Months202320222023202220232022
Operating income$439$460$206$218$220$227
Electric utility revenues$1,567$1,586$819$843$748$743
Electric production fuel and purchased power expenses(322)(359)(113)(150)(209)(209)
Electric transmission service expense(284)(271)(201)(188)(83)(83)
Utility Electric Margin (non-GAAP)961956505505456451
Gas utility revenues353356194191159165
Cost of gas sold expense(215)(216)(116)(112)(99)(104)
Utility Gas Margin (non-GAAP)13814078796061
Other utility revenues2523242211
Non-utility revenues4547
Other operation and maintenance expenses(338)(320)(181)(171)(133)(123)
Depreciation and amortization expenses(333)(332)(191)(189)(137)(139)
Taxes other than income taxes expense(59)(54)(29)(28)(27)(24)
Operating income$439$460$206$218$220$227

 Alliant Energy IPL WPL
Three Months2017 2016 2017 2016 2017 2016
Electric utility operating revenues
$840.6
 
$864.3
 
$489.0
 
$483.2
 
$351.6
 
$381.1
Electric production fuel and purchased power expenses(222.6) (245.9) (122.5) (125.0) (100.1) (120.9)
Electric transmission service expense(121.0) (138.6) (78.2) (95.9) (42.8) (42.7)
Utility Electric Margin (non-GAAP)497.0
 479.8
 288.3
 262.3
 208.7
 217.5
            
Gas utility operating revenues45.8
 39.5
 27.4
 23.9
 18.4
 15.6
Cost of gas sold(15.0) (12.5) (9.9) (8.0) (5.1) (4.5)
Utility Gas Margin (non-GAAP)30.8
 27.0
 17.5
 15.9
 13.3
 11.1
            
Other utility operating revenues11.2
 9.4
 11.0
 9.1
 0.2
 0.3
Non-regulated operating revenues9.3
 11.4
 
 
 
 
Asset valuation charges for Franklin County wind farm
 (86.4) 
 
 
 
Other operation and maintenance expenses(169.1) (148.6) (104.4) (94.8) (66.1) (54.2)
Depreciation and amortization expenses(120.7) (104.1) (66.2) (52.7) (53.6) (48.7)
Taxes other than income tax expense(27.0) (25.9) (14.4) (13.9) (11.8) (11.0)
Operating income
$231.5
 
$162.6
 
$131.8
 
$125.9
 
$90.7
 
$115.0

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 Alliant Energy IPL WPL
Nine Months2017 2016 2017 2016 2017 2016
Electric utility operating revenues
$2,199.1
 
$2,209.1
 
$1,217.6
 
$1,209.2
 
$981.5
 
$999.9
Electric production fuel and purchased power expenses(614.7) (646.3) (330.0) (324.8) (284.7) (321.5)
Electric transmission service expense(363.3) (396.8) (235.0) (270.7) (128.3) (126.1)
Utility Electric Margin (non-GAAP)1,221.1
 1,166.0
 652.6
 613.7
 568.5
 552.3
            
Gas utility operating revenues262.7
 248.7
 147.2
 142.6
 115.5
 106.1
Cost of gas sold(135.5) (132.3) (74.6) (76.3) (60.9) (56.0)
Utility Gas Margin (non-GAAP)127.2
 116.4
 72.6
 66.3
 54.6
 50.1
            
Other utility operating revenues34.4
 35.0
 33.3
 34.1
 1.1
 0.9
Non-regulated operating revenues29.9
 30.2
 
 
 
 
Asset valuation charges for Franklin County wind farm
 (86.4) 
 
 
 
Other operation and maintenance expenses(467.1) (438.2) (288.7) (279.8) (179.7) (157.2)
Depreciation and amortization expenses(342.7) (308.7) (181.0) (157.8) (158.8) (143.5)
Taxes other than income tax expense(79.1) (77.2) (41.1) (40.6) (35.3) (33.8)
Operating income
$523.7
 
$437.1
 
$247.7
 
$235.9
 
$250.4
 
$268.8

Operating Income Variances - Variances between periods in operating income for the three and ninesix months ended SeptemberJune 30, 20172023 compared to the same periods in 20162022 were as follows (in millions):
Three MonthsSix Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Total higher utility electric margin variance (Refer to details below)$7$1$6$5$—$5
Total lower utility gas margin variance (Refer to details below)(2)(1)(1)(2)(1)(1)
Total (higher) lower other operation and maintenance expenses variance (Refer to details below)32(18)(10)(10)
Total (higher) lower depreciation and amortization expenses (Refer to Note 2 for discussion of reductions to WPL's depreciation and amortization expense, which was partially offset by WPL's solar generation placed in service in 2022)
(1)(1)(1)(2)2
Other(2)(1)(5)1(3)
$5$1$4($21)($12)($7)

 Three Months Nine Months
 Alliant Energy IPL WPL Alliant Energy IPL WPL
Asset valuation charges for Franklin County wind farm in 2016 (refer to Note 3 for details)

$86
 
$—
 
$—
 
$86
 
$—
 
$—
Total utility electric margin variance (refer to details below)17
 26
 (9) 55
 39
 16
Total utility gas margin variance (refer to details below)4
 2
 2
 11
 6
 5
Total other operation and maintenance expenses variance (refer to details below)(21) (10) (12) (29) (9) (23)
Higher depreciation expense primarily due to additional plant in service in 2017, including impacts from Marshalltown(9) (9) (2) (20) (18) (6)
Higher depreciation expense at WPL due to updated depreciation rates effective January 2017 approved by the PSCW and FERC(3) 
 (3) (9) 
 (9)
Higher depreciation expense at IPL due to write-down of regulatory assets resulting from the proposed IPL electric rate review settlement in 2017(5) (5) 
 (5) (5) 
Other
 2
 
 (2) (1) (1)
 
$69
 
$6
 
($24) 
$87
 
$12
 
($18)

29

Electric and Gas Revenues and Sales Summary - Electric and gas revenues (in millions), and MWh and Dth sales (in thousands), for the three and ninesix months ended SeptemberJune 30 were as follows:
Alliant EnergyElectricGas
RevenuesMWhs SoldRevenuesDths Sold
20232022202320222023202220232022
Three Months
Retail$730$7295,9826,127$67$816,3037,605
Sales for resale:
Wholesale4954678677N/AN/AN/AN/A
Bulk power and other13151,104779N/AN/AN/AN/A
Transportation/Other7141415101325,77822,382
$799$8127,7787,598$77$9432,08129,987
Six Months
Retail$1,414$1,42012,18212,516$329$33028,61433,701
Sales for resale:
Wholesale951011,3761,398N/AN/AN/AN/A
Bulk power and other37362,3472,004N/AN/AN/AN/A
Transportation/Other21292931242658,39252,260
$1,567$1,58615,93415,949$353$35687,00685,961
Alliant EnergyElectric Gas
IPLIPLElectricGas
Revenues MWhs Sold Revenues Dths SoldRevenuesMWhs SoldRevenuesDths Sold
2017 2016 2017 2016 2017 2016 2017 201620232022202320222023202220232022
Three Months               Three Months
Retail
$745.7
 
$772.5
 6,722
 6,935
 
$37.4
 
$30.9
 3,744
 3,926
Retail$410$4213,3203,434$38$442,9463,778
Sales for resale75.6
 77.5
 1,390
 1,271
 
 
 
 
Sales for resale:Sales for resale:
WholesaleWholesale1416178179N/AN/AN/AN/A
Bulk power and otherBulk power and other1(3)360243N/AN/AN/AN/A
Transportation/Other19.3
 14.3
 22
 24
 8.4
 8.6
 19,787
 20,302
Transportation/Other6888689,55510,154

$840.6
 
$864.3
 8,134
 8,230
 
$45.8
 
$39.5
 23,531
 24,228
$431$4423,8663,864$44$5212,50113,932
Nine Months               
Six MonthsSix Months
Retail
$1,950.4
 
$1,970.4
 18,851
 19,139
 
$236.9
 
$222.9
 30,971
 32,720
Retail$771$8006,8637,085$179$17414,40617,380
Sales for resale204.8
 204.9
 3,564
 3,372
 
 
 
 
Sales for resale:Sales for resale:
WholesaleWholesale2631365373N/AN/AN/AN/A
Bulk power and otherBulk power and other9(5)856646N/AN/AN/AN/A
Transportation/Other43.9
 33.8
 72
 75
 25.8
 25.8
 54,849
 61,615
Transportation/Other13171616151721,58922,174

$2,199.1
 
$2,209.1
 22,487
 22,586
 
$262.7
 
$248.7
 85,820
 94,335
$819$8438,1008,120$194$19135,99539,554

WPLElectricGas
RevenuesMWhs SoldRevenuesDths Sold
20232022202320222023202220232022
Three Months
Retail$320$3082,6622,693$29$373,3573,827
Sales for resale:
Wholesale3538500498N/AN/AN/AN/A
Bulk power and other1218744536N/AN/AN/AN/A
Transportation/Other16674516,22312,228
$368$3703,9123,734$33$4219,58016,055
Six Months
Retail$643$6205,3195,431$150$15614,20816,321
Sales for resale:
Wholesale69701,0111,025N/AN/AN/AN/A
Bulk power and other28411,4911,358N/AN/AN/AN/A
Transportation/Other81213159936,80330,086
$748$7437,8347,829$159$16551,01146,407

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IPLElectric Gas
 Revenues MWhs Sold Revenues Dths Sold
 2017 2016 2017 2016 2017 2016 2017 2016
Three Months               
Retail
$443.3
 
$443.7
 3,784
 3,898
 
$22.0
 
$18.9
 2,189
 2,486
Sales for resale33.6
 29.5
 692
 389
 
 
 
 
Transportation/Other12.1
 10.0
 9
 11
 5.4
 5.0
 9,374
 8,783
 
$489.0
 
$483.2
 4,485
 4,298
 
$27.4
 
$23.9
 11,563
 11,269
Nine Months               
Retail
$1,105.5
 
$1,110.8
 10,761
 10,944
 
$129.9
 
$127.2
 16,548
 18,097
Sales for resale83.5
 75.5
 1,527
 1,056
 
 
 
 
Transportation/Other28.6
 22.9
 30
 31
 17.3
 15.4
 29,092
 27,066
 
$1,217.6
 
$1,209.2
 12,318
 12,031
 
$147.2
 
$142.6
 45,640
 45,163
WPLElectric Gas
 Revenues MWhs Sold Revenues Dths Sold
 2017 2016 2017 2016 2017 2016 2017 2016
Three Months               
Retail
$302.4
 
$328.8
 2,938
 3,037
 
$15.4
 
$12.0
 1,555
 1,440
Sales for resale42.0
 48.0
 698
 882
 
 
 
 
Transportation/Other7.2
 4.3
 13
 13
 3.0
 3.6
 10,413
 11,519
 
$351.6
 
$381.1
 3,649
 3,932
 
$18.4
 
$15.6
 11,968
 12,959
Nine Months               
Retail
$844.9
 
$859.6
 8,090
 8,195
 
$107.0
 
$95.7
 14,423
 14,623
Sales for resale121.3
 129.4
 2,037
 2,316
 
 
 
 
Transportation/Other15.3
 10.9
 42
 44
 8.5
 
$10.4
 25,757
 34,549
 
$981.5
 
$999.9
 10,169
 10,555
 
$115.5
 
$106.1
 40,180
 49,172

Temperatures - HDDSales Trends and CDD are calculated using a simple average of the high and low temperatures each day compared to a 65 degree base. Normal degree days are calculated using a rolling 20-year average of historical HDD and CDD. The following table summarizes the approximate quarterly temperature statistics and resulting impacts on IPL’s and WPL’sTemperatures - Alliant Energy’s retail electric and gas sales.sales volumes decreased 2% and 17%, respectively, for the three months ended June 30, 2023 compared to the same period in 2022, primarily due to changes in temperatures. Alliant Energy’s retail electric and gas sales volumes decreased 3% and 15%, respectively, for the six months ended June 30, 2023 compared to the same period in 2022, primarily due to changes in temperatures.
 2017 2016 Resulting Impact in 2017 Compared to 2016
First quarter (HDD)13% warmer than normal 10% warmer than normal Decrease in IPL’s and WPL’s electric and gas sales due to lower demand by customers for heating
Second quarter (CDD)2% cooler - 13% warmer than normal 10% - 35% warmer than normal Decrease in IPL’s and WPL’s electric sales due to lower demand by customers for air cooling
Third quarter (CDD)7% - 14% cooler than normal 20% warmer than normal Decrease in IPL’s and WPL’s electric sales due to lower demand by customers for air cooling


Estimated increases (decreases) to electric and gas margins from the impacts of temperatures for the three and ninesix months ended SeptemberJune 30 were as follows (in millions):
Electric MarginsGas Margins
Three MonthsSix MonthsThree MonthsSix Months
20232022Change20232022Change20232022Change20232022Change
IPL$—$7($7)($4)$11($15)($1)$2($3)($4)$4($8)
WPL8(8)(5)10(15)(1)(1)(3)2(5)
Total Alliant Energy$—$15($15)($9)$21($30)($2)$2($4)($7)$6($13)
 Electric Margins Gas Margins
 Three Months Nine Months Three Months Nine Months
 2017 2016 Change 2017 2016 Change 2017 2016 Change 2017 2016 Change
IPL
($4) 
$7
 
($11) 
($8) 
$7
 
($15) 
$—
 
$—
 
$—
 
($3) 
($2) 
($1)
WPL(4) 4
 (8) (9) 3
 (12) (1) (1) 
 (3) (2) (1)
Total Alliant Energy
($8) 
$11
 
($19) 
($17) 
$10
 
($27) 
($1) 
($1) 
$—
 
($6) 
($4) 
($2)


Electric Sales for Resale - Electric sales for resale volume changes were largely due to changes in sales in the wholesale energy markets operated by MISO. These changes are impacted by several factors, including the availability and dispatch of Alliant Energy’s EGUs and electricity demand within these wholesale energy markets. Changes in sales for resale revenues were largely offset by changes in fuel-related costs, and therefore, did not have a significant impact on electric margins.


Gas Transportation/Other - Gas transportation/other sales volume changes were largely due to changes in the gas volumes supplied to Alliant Energy’s natural gas-fired EGUs caused by the availability and dispatch of such EGUs. Changes in these transportation/other revenues did not have a significant impact on gas margins.
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Utility Electric Margin Variances - The following items contributed to increased (decreased) utility electric margins for the three and ninesix months ended SeptemberJune 30, 20172023 compared to the same periods in 2016 were2022 as follows (in millions):
Three MonthsSix Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Lower WPL electric fuel-related costs, net of recoveries$12$—$12$13$—$13
Higher revenues at IPL due to changes in the renewable energy rider (mostly offset by changes in income taxes)551212
Estimated changes in sales volumes caused by temperatures(15)(7)(8)(30)(15)(15)
Other5321037
$7$1$6$5$—$5
 Three Months Nine Months
 Alliant Energy IPL WPL Alliant Energy IPL WPL
Higher margins at IPL from the impact of its 2016 Test Year interim retail electric base rate increase (a)
$34
 
$34
 
$—
 
$54
 
$54
 
$—
Higher margins at WPL from the impact of its 2017/2018 Test Period retail electric base rate increase (b)4
 
 4
 42
 
 42
Retail electric customer billing credits at IPL in 20163
 3
 
 7
 7
 
Estimated changes in sales caused by temperatures (Refer to “Temperatures” above for details)(19) (11) (8) (27) (15) (12)
Changes in electric fuel-related costs, net of recoveries at WPL (c)(2) 
 (2) (11) 
 (11)
Revenue requirement adjustment in 2016 related to certain tax benefits from tax accounting method changes at IPL(4) (4) 
 (11) (11) 
Lower wholesale margins at WPL primarily due to the expiration of a wholesale power supply agreement on May 31, 2017(6) 
 (6) (8) 
 (8)
Other7
 4
 3
 9
 4
 5
 
$17
 
$26
 
($9) 
$55
 
$39
 
$16


(a)
In April 2017, IPL filed a request with the IUB to increase annual electric base rates for its Iowa retail electric customers by $176 million, or approximately 12%. An interim retail electric base rate increase of $102 million, or approximately 7%, on an annual basis, was implemented effective April 13, 2017. Refer to “Rate Matters” for discussion of IPL’s proposed IPL electric rate review settlement.
(b)
In December 2016,WPL received an order from the PSCW authorizing WPL to implement an increase in annual retail electric rates of $9 million, or approximately 1%. The $9 million net annual retail electric rate increase reflects a $60 million increase in base rates, partially offset by a $51 million reduction in fuel-related costs, using an estimate for 2017 fuel-related costs. The increase was effective January 1, 2017 and extends through the end of 2018. WPL no longer has winter rates that are lower than summer rates. Thus, the quarter-over-quarter variances resulting from the retail electric base rate increase will be smaller during the summer quarters, compared to the winter quarters.
(c)
WPL estimates the decrease to electric margins from amounts within the approved bandwidth of plus or minus 2% of forecasted fuel-related expenses determined by the PSCW each year was approximately $6 million for the nine months ended September 30, 2017. WPL estimates the increases to electric margins from amounts within the bandwidth were approximately $2 million and $5 million for the three and nine months ended September 30, 2016, respectively.

Electric Sales Trends - Alliant Energy’s retail sales volumes decreased 3% and 2% for the three and nine months ended September 30, 2017 compared to the same periods in 2016, respectively. The decreases were primarily due to the impact of lower residential and commercial sales due to cooler summer temperatures during the three and nine months ended September 30, 2017 compared to the same periods in 2016, partially offset by increases in WPL’s industrial sales from higher customer production and customer expansions. The nine-month decrease was also impacted by an extra day of retail sales during 2016 due to the leap year.

Utility Gas Margin Variances - The following items contributed to increased (decreased) utility gas margins for the three and ninesix months ended SeptemberJune 30, 20172023 compared to the same periods in 2016 were2022 as follows (in millions):
Three MonthsSix Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Estimated changes in sales volumes caused by temperatures($4)($3)($1)($13)($8)($5)
Higher revenues at IPL related to changes in recovery amounts for energy efficiency costs through the energy efficiency rider (mostly offset by changes in energy efficiency expense)1177
Higher revenue requirements at WPL (a)1155
Other1(1)(1)(1)
($2)($1)($1)($2)($1)($1)
 Three Months Nine Months
 Alliant Energy IPL WPL Alliant Energy IPL WPL
Higher margins at WPL from the impact of its 2017/2018 Test Period retail gas base rate increase (a)
$2
 
$—
 
$2
 
$6
 
$—
 
$6
Higher revenues at IPL due to lower gas tax benefit rider credits on customer’s bills (Refer to Note 2 for details)
1
 1
 
 4
 4
 
Estimated changes in sales caused by temperatures (Refer to “Temperatures” above for details)
 
 
 (2) (1) (1)
Other1
 1
 
 3
 3
 
 
$4
 
$2
 
$2
 
$11
 
$6
 
$5


(a)In December 2022, the PSCW issued an order authorizing an annual base rate increase of $9 million for WPL’s retail gas customers, covering the 2023 forward-looking Test Period, which reflects changes in weighted average cost of capital, updated depreciation rates and modifications to certain regulatory asset and regulatory liability amortizations. These retail gas rate changes were effective on January 1, 2023 and extend through the end of 2023.
(a)
In December 2016,WPL received an order from the PSCW authorizing WPL to implement an increase in annual retail gas base rates of $9 million, or approximately 13%. The increase is effective January 1, 2017 and extends through the end of 2018.


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Other Operation and Maintenance Expenses Variances - The following items contributed to (increased) decreased other operation and maintenance expenses for the three and ninesix months ended SeptemberJune 30, 20172023 compared to the same periods in 2016 were2022 as follows (in millions):
Three MonthsSix Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Higher energy efficiency expense at IPL (mostly offset by higher revenues)($2)($2)$—($9)($9)$—
Higher generation operation and maintenance expenses(9)(3)(6)(14)(1)(13)
Other147653
$3$2$—($18)($10)($10)
 Three Months Nine Months
 Alliant Energy IPL WPL Alliant Energy IPL WPL
Higher energy efficiency cost recovery amortizations at WPL (a)
($7) 
$—
 
($7) 
($20) 
$—
 
($20)
(Higher) lower bad debt expense(1) 1
 (2) (9) (3) (6)
Charges related to cancelled software projects in 2017(6) (3) (3) (6) (3) (3)
Write-down of regulatory assets due to the proposed IPL electric rate review settlement in 2017(4) (4) 
 (4) (4) 
(Higher) lower equity-based performance compensation expense(1) 
 
 7
 4
 3
Other(2) (4) 
 3
 (3) 3
 
($21) 
($10) 
($12) 
($29) 
($9) 
($23)


(a)The December 2016 PSCW order for WPL’s 2017/2018 Test Period electric and gas base rate review authorized changes in energy efficiency cost recovery amortizations for 2017 and 2018.

Interest ExpenseOther Income and OtherDeductions Variances - The following items contributed to (increased) decreased interest expenseother income and otherdeductions for the three and ninesix months ended SeptemberJune 30, 20172023 compared to the same periods in 2016 were2022 as follows (in millions):
Three MonthsSix Months
Alliant EnergyIPLWPLAlliant EnergyIPLWPL
Higher interest expense primarily due to financings completed in 2023 and 2022, and higher interest rates($18)$—($8)($38)$—($17)
Higher AFUDC primarily due to changes in construction work in progress balances related to WPL’s solar generation111919317
Other(1)(1)4(2)(4)3
($8)$—$5($21)($1)$3
 Three Months Nine Months
 Alliant Energy IPL WPL Alliant Energy IPL WPL
Higher interest expense primarily due to higher average outstanding long-term debt balances
($5) 
($2) 
$—
 
($14) 
($8) 
$—
Lower equity income from unconsolidated investments at WPL from the transfer of its investment in ATC LLC to ATI on December 31, 2016
 
 (9) 
 
 (29)
Higher (lower) AFUDC primarily due to increased (decreased) construction work in progress balances(6) (9) 3
 (8) (11) 4
Other1
 
 
 4
 
 (1)
 
($10) 
($11) 
($6) 
($18) 
($19) 
($26)


Income Taxes - Refer to Note 8 9 for details of effective income tax rates from continuing operations.rates.


STRATEGIC OVERVIEWLIQUIDITY AND CAPITAL RESOURCES


The strategic overviewliquidity and capital resources summary included in the 2016 2022 Form 10-K has not changed materially, except as described below.


Generation Plans -
Natural Gas-Fired Generation -
IPL’s Construction of Marshalltown - Refer to Note 3 for discussion of IPL’s construction of Marshalltown, which was completed in April 2017. Final capital expenditures are currently estimated to be approximately $645 million to construct the EGU and a pipeline to supply natural gas to the EGU, excluding transmission network upgrades and AFUDC.

WPL’s Construction of West Riverside - In October 2017, WPL received an order from the PSCW authorizing various electric cooperatives, which currently have wholesale power supply agreements with WPL, to acquire approximately 65 MW of West Riverside while the EGU is being constructed. As part of the electric cooperatives’ acquisitions, which are currently expected to be completed in the fourth quarter of 2017, the current wholesale power supply agreements with the various electric cooperatives will be extended by at least four years until 2026 with automatic continuation of such agreements unless terminated by either party, with a five-year notice requirement.


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Wind Generation - The strategic plan includes the planned expansion of wind generation as follows. Estimated capital expenditures for the planned wind generation projects for 2017 through 2020 are included in the “Renewable projects” line in the construction and acquisition expenditures table in “Liquidity and Capital Resources.”
Wind Generation (a)Regulatory Application Filing Status
IPL - up to 500 MWApproved by the IUB in October 2016
IPL - up to 500 MW (b)Filed with the IUB in August 2017
WPL - up to 200 MW (b)Plan to file with the PSCW in the fourth quarter of 2017

(a)IPL and WPL believe their respective planned expansion of wind generation will qualify for the full level of production tax credits as a result of progress payments in 2016 for wind turbines, and plan to place these wind projects into service by the fourth quarter of 2020.
(b)The amount and timing of these wind projects will largely depend on regulatory approvals and the acquisition of wind sites.

IPL’s Expansion of Wind Generation - In October 2016, IPL received approval from the IUB for up to 500 MW of new wind generation. In August 2017, IPL filed an application with the IUB for advance rate-making principles for up to 500 MW of additional wind generation. The advance rate-making principles requested by IPL in the August 2017 application were as follows:

Up to 500 MW of additional wind generation that qualifies for the full level of production tax credits, as long as the project is located in Iowa, with a cost cap of $1,780/kilowatt, including AFUDC and transmission costs. Any costs incurred in excess of this $1,780/kilowatt cost cap are expected to be incorporated into rates if determined to be reasonable and prudent.
A depreciable life of the wind generation facilities of 40 years, unless changed as a result of a contested case before the IUB.
An 11.0% return on common equity, with the exception of certain transmission facilities classified as intangible assets, which would earn the rate of return on common equity the IUB finds reasonable during a future rate review.
A return on common equity for the calculation of AFUDC during the construction period that is the greater of 10.0% or the percentage the IUB finds reasonable during IPL’s retail electric rate review for the 2016 Test Year.
The application of double leverage is deferred until IPL’s next retail electric base rate review or other future proceeding.
Amortization over a 10-year period of IPL’s prudently incurred and unreimbursed costs, effective with IPL’s next retail electric base rate review, if IPL cancels the construction of the wind generation.

Franklin County Wind Farm - Refer to Note 3 for discussion of the transfer of the Franklin County wind farm assets from AEF to IPL in April 2017.

WPL’s Proposed Acquisition of Forward Wind Energy Center - In October 2017, WPL, along with Wisconsin Public Service Corporation and Madison Gas and Electric Company, entered into definitive agreements to acquire the assets of the Forward Wind Energy Center (FWEC), which is a 129 MW wind farm located in Wisconsin. WPL currently expects to acquire 55 MW of FWEC for approximately $74 million. WPL currently expects to file for approval from the PSCW and FERC in the fourth quarter of 2017, with decisions expected by the second quarter of 2018. WPL, Wisconsin Public Service Corporation and Madison Gas and Electric Company have been receiving electricity from FWEC under purchased power agreements since FWEC began commercial operations in 2008. Upon completion of the acquisitions, such purchased power agreements will terminate. This proposed acquisition is included in WPL’s plans for up to 200 MW of additional wind generation discussed above.

Coal-Fired Generation -
IPL’s Environmental Controls Projects - In May 2017, the IUB approved IPL’s most recent emissions plan and budget, which includes the SCR currently under construction at Ottumwa Unit 1.

Plant Retirements and Fuel Switching - In June 2017, IPL retired Sutherland Units 1 and 3 and Dubuque Units 3 and 4, and fuel switched Marshalltown Combustion Turbine Units 1-3 from oil to natural gas. Refer to Note 2 for further discussion of the Sutherland Units 1 and 3 retirement.

Non-regulated Operations - The strategic plan for Alliant Energy’s non-regulated operations involves maintaining a modest portfolio of businesses that are accretive to earnings and cash flows. The non-regulated strategic plan continues to evolve through exploration of renewable investment opportunities within and outside of Alliant Energy’s service territories.

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Table of Contents



Non-regulated Wind Investment in Oklahoma - In July 2017, a wholly-owned subsidiary of AEF acquired a 50% cash equity ownership interest in a 225 MW non-regulated wind farm located in Oklahoma. Refer to Note 5(a) for further discussion.

RATE MATTERS

The rate matters summary included in the 2016 Form 10-K has not changed materially, except as described below.

IPL’s Retail Electric Rate Review (2016 Test Year) - In April 2017, IPL filed a request with the IUB to increase annual electric base rates for its Iowa retail electric customers and interim rates were implemented effective April 13, 2017. In September 2017, IPL reached a partial, non-unanimous settlement agreement with the Iowa Office of Consumer Advocate, the Iowa Business Energy Coalition and the Large Energy Group. The requested interim and final (based on proposed settlement) rate increases were calculated based on the following (Return on Common Equity (ROE)):
 Interim Rates Final Rates (Proposed Settlement)
Regulatory capital structure:   
Common equity49.1% 49.0%
Long-term debt46.3% 46.8%
Preferred equity4.6% 4.2%
After-tax weighted-average cost of capital:   
Marshalltown (ROE - 11.0%)8.1% 8.0%
Emery (ROE - 12.23%)8.7% 8.6%
Whispering Willow - East (ROE - 11.7%)8.4% 8.3%
Other (ROE - 9.6%) (a)7.4% 7.3%
Retail electric rate base (b)$3.8 billion $4.0 billion

(a)Other ROE of 9.6% for interim rates reflects the application of double leverage. Prior to application of double leverage, Other ROE for interim rates was 10.0%. Other ROE of 9.6% for final rates (based on proposed settlement) does not reflect the application of double leverage.
(b)The retail electric rate base for interim rates includes post-test year capital additions placed in service prior to the rate filing in April 2017, including Marshalltown and the Franklin County wind farm. The retail electric rate base for final rates (based on proposed settlement) also includes deferred tax assets for production tax credits generated by Whispering Willow - East and post-test year capital additions placed in service by September 30, 2017.

Refer to Note 2 for discussion of IPL’s initial request, interim rates and proposed settlement, as well as details for a write-down of regulatory assets recorded by IPL in the third quarter of 2017 related to the proposed settlement.

WPL’s Retail Fuel-related Rate Filings - Refer to Note 2 for discussion of WPL’s retail fuel-related rate filings for the 2016, 2017 and 2018 Test Years.

Planned Utility Rate Reviews -
IPL’s Retail Gas Rate Review (2017 Test Year) - IPL currently expects to make a retail gas rate filing in the second quarter of 2018 based on a 2017 historical Test Year. The key drivers for the anticipated filing include recovery of capital projects. Any rate changes are expected to be implemented in two phases with interim rates effective approximately 10 days after the filing and final rates effective approximately 10 months after the filing date.

WPL’s Retail Electric and Gas Rate Review (2019/2020 Test Period) - WPL currently expects to make a retail electric and gas rate filing in the second quarter of 2018 for the 2019/2020 Test Period. Any rate changes granted from this request are expected to be effective on January 1, 2019. WPL currently expects a decision from the PSCW regarding this rate filing by the end of 2018.

ENVIRONMENTAL MATTERS

The environmental matters summary included in the 2016 Form 10-K has not changed materially.

LEGISLATIVE MATTERS

The legislative matters summary included in the 2016 Form 10-K has not changed materially.

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LIQUIDITY AND CAPITAL RESOURCES

The liquidity and capital resources matters summary included in the 2016 Form 10-K has not changed materially, except as described below.

Liquidity Position - At SeptemberJune 30, 2017,2023, Alliant Energy had $9$13 million of cash and cash equivalents, $570$554 million ($139103 million at the parent company, $256$195 million at IPL and $175$256 million at WPL) of available capacity under the single revolving credit facility and $2$50 million of available capacity at IPL under its sales of accounts receivable program.


Capital Structure - Capital structures at SeptemberJune 30, 20172023 were as follows (Long-term Debt (including current maturities) (LD); Short-term Debt (SD); Common Equity (CE); IPL’s Preferred Stock (PS)):
lnt9302017_chart-00639.jpglnt9302017_chart-01779.jpglnt9302017_chart-03185.jpg636637638
Cash Flows - Selected information from the cash flows statements was as follows (in millions):
Alliant EnergyIPLWPL
202320222023202220232022
Cash, cash equivalents and restricted cash, January 1$24$40$15$34$5$2
Cash flows from (used for):
Operating activities3113005283268198
Investing activities(482)(370)(15)60(402)(384)
Financing activities16150(43)(164)132188
Net increase (decrease)(10)(20)(6)(21)(2)2
Cash, cash equivalents and restricted cash, June 30$14$20$9$13$3$4

 Alliant Energy IPL WPL
 2017 2016 2017 2016 2017 2016
Cash and cash equivalents, January 1
$8.2
 
$5.8
 
$3.3
 
$4.5
 
$4.2
 
$0.4
Cash flows from (used for):    ��      
Operating activities883.4
 654.0
 470.6
 256.5
 361.2
 439.3
Investing activities(1,072.3) (771.8) (493.6) (435.4) (470.2) (326.7)
Financing activities189.9
 196.7
 24.4
 252.1
 108.0
 (107.4)
Net increase (decrease)1.0
 78.9
 1.4
 73.2
 (1.0) 5.2
Cash and cash equivalents, September 30
$9.2
 
$84.7
 
$4.7
 
$77.7
 
$3.2
 
$5.6

32

Operating Activities -
Nine Months Ended September 30, 2017 vs. Nine Months Ended September 30, 2016 - The following items contributed to increased (decreased) operating activity cash flows for the ninesix months ended SeptemberJune 30, 20172023 compared to the same period in 20162022 (in millions):
Alliant EnergyIPLWPL
Changes in levels of gas stored underground and prepaid gas costs$49$21$28
Timing of WPL’s fuel-related cost recoveries from retail electric customers4141
Changes in cash collateral and deposit balances at Corporate Services14
Timing of intercompany payments and receipts835
Decreased collections from IPL’s and WPL’s retail customers caused by temperature impacts on electric and gas sales(43)(23)(20)
Changes in interest payments(33)(15)
Higher contributions to qualified defined benefit pension plans(12)(12)
Other (primarily due to other changes in working capital)(5)(37)13
$11($31)$70
 Alliant Energy IPL WPL
Changes in the level of cash proceeds from IPL’s sales of accounts receivable
$95
 
$95
 
$—
Higher collections at IPL due to interim retail electric base rate increase effective April 13, 201754
 54
 
Higher collections at WPL due to new retail electric and gas base rates in 201748
 
 48
Changes in cash collateral balances38
 
 
Changes in levels of production fuel11
 23
 (12)
Timing of WPL’s fuel-related cost recoveries from customers(49) 
 (49)
Changes in income taxes paid/refunded(3) 13
 (40)
Other (primarily due to other changes in working capital)35
 29
 (25)
 
$229
 
$214
 
($78)



39



Investing Activities -
Nine Months Ended September 30, 2017 vs. Nine Months Ended September 30, 2016 - The following items contributed to increased (decreased) investing activity cash flows for the ninesix months ended SeptemberJune 30, 20172023 compared to the same period in 20162022 (in millions):
Alliant EnergyIPLWPL
Higher utility construction and acquisition expenditures (a)($208)($79)($129)
Higher other construction and acquisition expenditures(19)
Proceeds from sales of partial ownership interest in West Riverside120120
Changes in the amount of cash receipts on sold receivables3939
Other(44)(35)(9)
($112)($75)($18)
 Alliant Energy IPL WPL
Higher utility construction expenditures (a)
($166) 
($34) 
($147)
Non-regulated wind investment in Oklahoma (Refer to Note 5(a) for details)
(98) 
 
Proceeds from the liquidation of company-owned life insurance policies in 2016(31) (19) 
Other(6) (5) 3
 
($301) 
($58) 
($144)


(a)Largely due to higher expenditures for WPL’s West Riverside facility, IPL’s and WPL’s electric and gas distribution systems and IPL’s expansion of wind generation, partially offset by lower expenditures for IPL’s Marshalltown facility and WPL’s scrubber and baghouse at Edgewater Unit 5.

(a)Largely due to higher expenditures for IPL and WPL’s solar generation.

Construction and Acquisition Expenditures - ConstructionIn March 2023, WPL notified the PSCW that it currently expects estimated construction costs and related rate base additions associated with its 414 MW of new solar generation will exceed amounts approved by the PSCW in June 2022 by approximately 10-14% due to higher commodity, labor and other site-specific costs. A significant portion of these higher estimated construction costs are included in the anticipated construction and acquisition expenditures for 2017 through 2021 are currently anticipated as follows (in millions). Cost estimates represent Alliant Energy’s, IPL’sincluded in “Liquidity and WPL’s portion of total escalated construction expenditures and exclude AFUDC and capitalized interest, if applicable. Such estimates reflect impacts to Alliant Energy’s and WPL’s capital expenditures resulting from purchase options by certain electric cooperatives for a partial ownership interestCapital Resources” in West Riverside, as well as additional capital expenditures related to Columbia that WPL is expected to incur related to agreements entered into with Wisconsin Public Service Corporation and Madison Gas and Electric Company. Refer to “Strategic Overview” for further discussion of certain key projects impacting construction and acquisition plans related to the utility business.2022 Form 10-K.

 Alliant Energy IPL WPL
 20172018201920202021 20172018201920202021 20172018201920202021
Generation:                 
Renewable projects
$180

$655

$850

$140

$85
 
$210

$565

$725

$50

$85
 
$—

$90

$125

$90

$—
West Riverside235
225
90
10

 




 235
225
90
10

Marshalltown30




 30




 




Other220
140
95
150
140
 85
60
50
80
75
 135
80
45
70
65
Distribution:                 
Electric systems480
440
435
485
560
 290
260
250
290
345
 190
180
185
195
215
Gas systems130
130
95
90
115
 90
75
50
55
65
 40
55
45
35
50
Other210
130
110
125
100
 30
25
20
25
20
 10
10
10
10
10
 
$1,485

$1,720

$1,675

$1,000

$1,000
 
$735

$985

$1,095

$500

$590
 
$610

$640

$500

$410

$340

Financing Activities -
Nine Months Ended September 30, 2017 vs. Nine Months Ended September 30, 2016 - The following items contributed to increased (decreased) financing activity cash flows for the ninesix months ended SeptemberJune 30, 20172023 compared to the same period in 20162022 (in millions):
Alliant EnergyIPLWPL
Higher net proceeds from issuance of long-term debt$212$—$297
Higher net proceeds from common stock issuances63
Higher payments to retire long-term debt(100)
Net changes in the amount of commercial paper and other short-term borrowings outstanding(30)55(232)
Capital contributions from noncontrolling interest(29)(29)
(Higher) lower common stock dividends(11)20(3)
Higher (lower) capital contributions from IPL’s and WPL’s parent company, Alliant Energy40(85)
Other66(4)
$111$121($56)
 Alliant Energy IPL WPL
Lower net proceeds from issuance of long-term debt
($300) 
($300) 
$—
Net changes in the amount of commercial paper and other short-term borrowings outstanding203
 44
 180
Higher net proceeds from common stock issuances123
 
 
Higher capital contributions from IPL’s and WPL’s parent company, Alliant Energy
 35
 40
Other (includes higher dividend payments in 2017)(33) (7) (5)
 
($7) 
($228) 
$215


FERC Financing Authorization - Pursuant to a 2015 FERC authorization, IPL’s current remaining authority for short-term debt securities outstanding at any one time (including borrowings from its parent) is $256 million as of September 30, 2017.

State Regulatory Financing Authorization - In August 2017,March 2023, WPL received authorization from the PSCW to have up to $400$500 million of short-term borrowings and/or letters of credit outstanding at any time through the earlier of the expiration date of WPL’s credit facility agreement (including extensions) or December 2024.agreement.


Common Stock DividendsIssuances - Refer to Executive Overview” for discussion of expected common stock dividends in 2018.

40




Common Stock Issuances - Refer to Note 6 for discussion of common stock issuances by Alliant Energy during the nine months ended September 30, 2017.in 2023.

Short-term Debt - Refer to Executive OverviewNote 7(a) for discussion of expectedAlliant Energy’s, IPL’s and WPL’s single credit facility agreement that was amended and extended in March 2023, which includes a revised cross-default provision related to prepayment of material debt prior to the stated maturity and certain other confirming changes, as well as details for proceeds from AEF’s December 2022 term loan credit agreement.

Long-term Debt - Refer to Note 7(b) for discussion of various issuances and retirements of common stocklong-term debt by Alliant Energy, AEF, IPL and WPL in 2018.2023.

Short-term Debt
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Interest Rate Risk - In July 2017, AEF entered intoAs of June 30, 2023, Alliant Energy’s exposure to risk resulting from changes in interest rates associated with variable-rate borrowings was mitigated primarily due to its issuance of convertible senior notes and an interest rate swap on a $95 million, 364-dayportion of its variable-rate term loan credit agreement (with Alliant Energyborrowings, as guarantor) related to the acquisition of a non-regulated wind farm located in Oklahoma. Refer to Note 7(a) for further discussion.

In August 2017, Alliant Energy, IPL and WPL entered into a single new credit facility agreement, which expires in August 2022. The new credit facility agreement includes financial covenants similar to those that were included in the previous credit facility agreements. As of September 30, 2017, the short-term borrowing capacity totaled $1 billion ($300 million for Alliant Energy at the parent company level, $300 million for IPL and $400 million for WPL). There are currently 13 lenders that participate in the credit facility, with aggregate respective commitments ranging from $20 million to $130 million. The credit facility includes a $100 million letter of credit commitment and $50 million swingline commitment, which are available to each of Alliant Energy, IPL and WPL. Subject to certain conditions, Alliant Energy, IPL and WPL may each reallocate and change its initial sublimit up to $500 million, $400 million and $500 million, respectively, within the $1 billion total commitment. Subject to certain conditions, Alliant Energy, IPL and WPL may exercise two extension options, each extending the maturity date by one year. The credit facility has a provision to expand the facility size up to an additional $300 million, for a potential total commitment of $1.3 billion, subject to lender approval for Alliant Energy and subject to lender and regulatory approvals for IPL and WPL.

Long-term Debt - Refer to Note 7(b) for discussion ofwell as WPL’s issuance of $300 milliongreen bonds, all of debentureswhich were executed in October 2017the first quarter of 2023. Assuming the impact of a hypothetical 100 basis point increase in interest rates on variable-rate borrowings and $40 millioncash amounts outstanding under IPL’s sales of commercial paper outstandingaccounts receivable program at SeptemberJune 30, 2017 classified as long-term debt at2023, Alliant Energy and IPL. Refer to “Executive Overview” for discussion of expected issuances of long-term debt in 2018.Energy’s annual pre-tax expense would increase by approximately $7 million.


Off-Balance Sheet Arrangements and Certain Financial Commitments - A summary of Alliant Energy’s and IPL’s off-balance sheet arrangements and Alliant Energy’s, IPL’s and WPL’s contractual obligations is included in the 20162022 Form 10-K and has not changed materially from the items reported in the 20162022 Form 10-K except as described below. Refer to Note 4 for information regarding IPL’s sales of accounts receivable program. Refer to Note 12(d) for information regarding various guarantees and indemnifications related to Alliant Energy’s cash equity ownership interest in a non-regulated wind farm and Alliant Energy’s and IPL’s prior divestiture activities.

Certain Financial Commitments -
Contractual Obligations - A summary of Alliant Energy’s, IPL’s and WPL’s contractual obligations is included in the 2016 Form 10-K and has not changed materially from the items reported in the 2016 Form 10-K,, except for the items described in Notes 7(b)4, 12(a)7 and 12(b)13.


OTHER MATTERS

Market Risk Sensitive Instruments and Positions - The market risks summary included in the 2016 Form 10-K has not changed materially.

Commodity Price - Refer to Note 2 for discussion of WPL’s retail fuel-related rate filings for the 2016, 2017 and 2018 Test Years.

New Accounting Standards - Refer to Note 1(b) for discussion of new accounting standards impacting Alliant Energy, IPL and WPL.

Critical Accounting Policies and Estimates - The summary of critical accounting policies and estimates included in the 2016 2022 Form 10-K has not changed materially, except as described below.

Contingencies - In the first quarter of 2017, all warranty periods and performance guarantees expired, and all outstanding warranty claims were resolved, related to Alliant Energy’s past divestiture of RMT. Refer to Note 12(d) for further discussion.

Regulatory Assets and Regulatory Liabilities - Refer to Note 2 for discussion of a write-down of regulatory assets in the third quarter of 2017 related to the recovery of Sutherland Units 1 and 3, and asset retirement obligations deemed no longer probable of recovery in future rates, due to the proposed IPL electric rate review settlement.

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Long-Lived Assets -
Regulated Operations -
Generating Units Subject to Early Retirement - Refer to Note 2 for discussion of IPL’s June 2017 retirement of Sutherland Units 1 and 3, and a write-down of regulatory assets inIn May 2023, IPL retired the third quarter of 2017 related to the recovery of these EGUs due to the proposedLansing Generating Station. IPL electric rate review settlement.

Alliant Energy and WPL concluded that Edgewater Unit 4 met the criteria to be considered probable of abandonment as of September 30, 2017. WPL is currently allowed a full recovery of and a full return on this EGU from both its retail and wholesale customers, and as a result, Alliant Energy and WPLIPL concluded that no impairment was required as of SeptemberJune 30, 2017.

Non-regulated Operations -
Franklin County Wind Farm -2023. Refer to Note 32 for further discussion of the transfer of the Franklin County wind farm assets from AEF to IPL in April 2017.Lansing retirement.


Other Future ConsiderationsEnvironmental Matters - The summary of other future considerationsenvironmental matters included in the 2016 2022 Form 10-K has not changed materially, except as described below, and as discussed earlier in MDA andbelow.

Environmental Regulation -
Clean Air Act (CAA) Section 111(d) - In May 2023, the Notes in Item 1.

2018 Electric Transmission Service Expense - Alliant Energy and IPL currently estimate their total electric transmission service expense in 2018 will be higher than the comparable expense in 2017 by approximately $10 million and $40 million, respectively, as a resultEPA published proposed standards under Section 111(d) of the timingCAA, which establish emission guidelines for states to implement Best System of Emission Reduction standards for greenhouse gases emissions from existing fossil-fueled EGUs and certain combustion turbines, and would be phased in beginning in 2030. The EPA also proposed to repeal the Affordable Clean Energy rule. The EPA’s proposed standards would require states to implement plans to reduce carbon dioxide emissions from existing fossil-fueled EGUs and certain combustion turbines through various measures, including retirement, enforceable limits on operational capacity, co-firing with low-greenhouse gases fuels, or other technological controls. State plans must be submitted within 24 months of the MISO transmission owner return on equity complaint refunds received in 2017final rule’s effective date and anticipatedare subject to EPA approval. The proposed standards could impact IPL’s coal-fired Ottumwa Generating Station, George Neal Generating Station, Prairie Creek Generating Station Unit 3 and Louisa Generating Station, and IPL’s natural gas-fired Burlington Generating Station and Prairie Creek Generating Station Unit 4. In addition, the proposed standards could impact natural gas-fired combustion turbines with a capacity of 300 MW or more, including IPL’s Marshalltown Generating Station and Emery Generating Station, and WPL’s Riverside Energy Center and West Riverside Energy Center. The proposed standards are currently not expected to impact WPL’s coal-fired Columbia Energy Center or Edgewater Generating Station given current plans to retire these EGUs prior to the proposed 2030 implementation deadline. The timeline for expected issuance of the EPA’s final reconsidered 111(d) rule cannot be predicted with certainty, but is expected to be receivedissued in 2018, and the related impacts on IPL’s transmission cost rider. WPL currently estimates its total electric transmission service expense in 2018 will be lower than the comparable expense in 2017 by approximately $30 million due to the return of a regulatory liability balance in the escrow account for its electric transmission service expense. WPL’s 2017 and 2018 retail cost estimates were approved in WPL’s retail electric rate review for the 2017/2018 Test Period, and exclude the impacts of an expected lower return on equity and associated refunds resulting from the MISO transmission owner return on equity complaints received in 2017 and anticipated to be received in 2018.

MISO Transmission Owner Return on Equity Complaints - Refer to Note 2 for discussion of refunds that2024. Alliant Energy, IPL and WPL received duringare currently unable to predict with certainty the nine months ended September 30, 2017 relatedfuture outcome or impact of these matters.

Clean Air Act Section 111(b) - In May 2023, the EPA published proposed standards under Section 111(b) of the CAA, which establish carbon dioxide emissions limits from certain new and reconstructed fossil-fueled EGUs and would apply prospectively. The timeline for expected issuance of the EPA’s final reconsidered 111(b) rule cannot be predicted with certainty, but is expected to a complaint previously filed by a group of MISO cooperativebe issued in 2024. Marshalltown and municipal utilities requesting a reductionWest Riverside are currently subject to the base returnEPA’s Section 111(b) regulation. Alliant Energy, IPL and WPL are currently unable to predict with certainty the future outcome or impact of these standards.

Coal Combustion Residuals (CCR) Rule - In May 2023, the EPA published proposed amendments to the CCR Rule, which regulates CCR as a non-hazardous waste. These proposed amendments would expand the scope of regulation to include coal ash ponds at sites that no longer produce electricity and inactive landfills, including some IPL and WPL facilities. Alliant Energy, IPL and WPL are currently unable to predict with certainty the future outcome or impact of these updates.

Environmental Stewardship - Alliant Energy’s current voluntary environmental-related goals include the following:

By 2030, reduce greenhouse gases emissions from its utility operations by 50% from 2005 levels, reduce its electric utility water supply by 75% from 2005 levels and electrify 100% of its owned light-duty fleet vehicles.
By 2040, eliminate all coal-fired EGUs from its generating fleet and reduce greenhouse gases emissions from its utility operations by 80% from 2005 levels.
By 2050, aspire to achieve net-zero greenhouse gases emissions from its utility operations.

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Alliant Energy’s aspirational greenhouse gases goal includes EPA reportable emissions based on equity usedapplicable regulatory compliance requirements for carbon dioxide, methane and nitrous oxide from its owned fossil-fueled EGUs and distribution of natural gas. In addition, Alliant Energy’s environmental stewardship efforts include a goal to partner to plant more than 1 million trees by MISO transmission owners, including ITCthe end of 2030. Future updates to sustainable energy plans and ATC LLC.attaining these goals will depend on future economic developments, evolving energy technologies and emerging trends in Alliant Energy’s service territories.


ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK


Quantitative and Qualitative Disclosures About Market Risk are reported in the 2022 Other Matters - Market Risk Sensitive InstrumentsForm 10-K and Positions” in MDA.have not changed materially.


ITEM 4. CONTROLS AND PROCEDURES


Alliant Energy’s, IPL’s and WPL’s management evaluated, with the participation of each of Alliant Energy’s, IPL’s and WPL’s Chief Executive Officer, Chief Financial Officer and Disclosure Committee, the effectiveness of the design and operation of Alliant Energy’s, IPL’s and WPL’s disclosure controls and procedures (as defined in Rule 13a-15(e) of the Securities Exchange Act of 1934)1934, as amended) as of SeptemberJune 30, 20172023 pursuant to the requirements of the Securities Exchange Act of 1934, as amended. Based on their evaluation, the Chief Executive OfficerOfficers and the Chief Financial Officer concluded that Alliant Energy’s, IPL’s and WPL’s disclosure controls and procedures were effective as of the quarter ended SeptemberJune 30, 2017.2023.


There was no change in Alliant Energy’s, IPL’s and WPL’s internal control over financial reporting that occurred during the quarter ended SeptemberJune 30, 20172023 that has materially affected, or is reasonably likely to materially affect, Alliant Energy’s, IPL’s or WPL’s internal control over financial reporting.


PART II. OTHER INFORMATION


ITEM 1. LEGAL PROCEEDINGS

None. SEC regulations require Alliant Energy, IPL and WPL to disclose information about certain proceedings arising under federal, state or local environmental provisions when a governmental authority is a party to the proceedings and such proceedings involve potential monetary sanctions that Alliant Energy, IPL and WPL reasonably believe will exceed a specified threshold. Pursuant to the SEC regulations, Alliant Energy, IPL and WPL use a threshold of $1 million for purposes of determining whether disclosure of any such proceedings is required. Applying this threshold, there are no environmental matters to disclose for this period.

ITEM 1A. RISK FACTORS


The risk factors described in Item 1A in the 2016 2022 Form 10-K have not changed materially.



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ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS


A summary of Alliant Energy common stock repurchases for the quarter ended SeptemberJune 30, 20172023 was as follows:

Total NumberAverage PriceTotal Number of SharesMaximum Number (or Approximate
of SharesPaid PerPurchased as Part ofDollar Value) of Shares That May
PeriodPurchased (a)SharePublicly Announced PlanYet Be Purchased Under the Plan (a)
April 1 through April 307,265$55.05N/A
May 1 through May 313,39453.99N/A
June 1 through June 302952.52N/A
10,68854.71

(a)All shares were purchased on the open market and held in a rabbi trust under the Alliant Energy Deferred Compensation Plan. There is no limit on the number of shares of Alliant Energy common stock that may be held under the Deferred Compensation Plan, which currently does not have an expiration date.

ITEM 5. OTHER INFORMATION

(c)During the quarter ended June 30, 2023, no director or officer of Alliant Energy, IPL or WPL adopted or terminated a Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement, as each term is defined in Item 408(a) of Regulation S-K.

  Total Number Average Price Total Number of Shares Maximum Number (or Approximate
  of Shares Paid Per Purchased as Part of Dollar Value) of Shares That May
Period Purchased (a) Share Publicly Announced Plan Yet Be Purchased Under the Plan (a)
July 1 through July 31 2,299
 
$39.81
  N/A
August 1 through August 31 3,727
 41.93
  N/A
September 1 through September 30 337
 42.45
  N/A
  6,363
 41.19
   

(a)All shares were purchased on the open market and held in a rabbi trust under the Alliant Energy Deferred Compensation Plan. There is no limit on the number of shares of Alliant Energy common stock that may be held under the Deferred Compensation Plan, which currently does not have an expiration date.35

Refer to


ITEM 6. EXHIBITS


The following Exhibits are filed herewith or incorporated herein by reference.
herewith.
Exhibit NumberDescription
31.1
101.INSInline XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document
101.SCHInline XBRL Taxonomy Extension Schema Document
101.CALInline XBRL Taxonomy Extension Calculation Linkbase Document
101.LABInline XBRL Taxonomy Extension Label Linkbase Document
101.PREInline XBRL Taxonomy Extension Presentation Linkbase Document
101.DEFInline XBRL Taxonomy Extension Definition Linkbase Document
104Cover Page Interactive Data File (embedded within the Inline XBRL document)



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SIGNATURES


Pursuant to the requirements of the Securities Exchange Act of 1934, Alliant Energy Corporation, Interstate Power and Light Company and Wisconsin Power and Light Company have each duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized on the 3rd4th day of November 2017.August 2023.

ALLIANT ENERGY CORPORATION
Registrant
ALLIANT ENERGY CORPORATION
Registrant
By: /s/ Benjamin M. BilitzChief Accounting Officer and Controller
Benjamin M. Bilitz(Principal Accounting Officer and Authorized Signatory)
INTERSTATE POWER AND LIGHT COMPANY
Registrant
By: /s/ Benjamin M. BilitzChief Accounting Officer and Controller
Benjamin M. Bilitz(Principal Accounting Officer and Authorized Signatory)
WISCONSIN POWER AND LIGHT COMPANY
Registrant
By: /s/ Benjamin M. BilitzChief Accounting Officer and Controller
Benjamin M. Bilitz(Principal Accounting Officer and Authorized Signatory)



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