Alliant Energy 10-Q 2023-09-30

Filed 2023-11-03. 8 sections, 268K characters. Original on sec.gov · Markdown · JSON

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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

For the quarterly period ended September 30, 2023

or

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

alliantenergylogo.jpg

Name 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

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 registrant (1) has 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 registrant was required to file such reports), and (2) has 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 registrant has submitted electronically every Interactive Data File required to be submitted 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 registrant was required to submit 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 registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth 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 ☐

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 registrant is a shell company (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 September 30, 2023:

Alliant Energy Corporation, Common Stock, $0.01 par value, 255,179,087 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)

Table of Contents

TABLE OF CONTENTS

Page
Definitions1
Forward-looking Statements1
Part I. Financial Information3
Item 1. Condensed Consolidated Financial Statements (Unaudited)3
Alliant Energy Corporation3
Interstate Power and Light Company6
Wisconsin Power and Light Company9
Combined Notes to Condensed Consolidated Financial Statements12
1. Summary of Significant Accounting Policies12
2. Regulatory Matters12
3. Property, Plant and Equipment13
4. Receivables13
5. Investments14
6. Common Equity14
7. Debt16
8. Revenues18
9. Income Taxes18
10. Benefit Plans19
11. Derivative Instruments20
12. Fair Value Measurements21
13. Commitments and Contingencies24
14. Segments of Business25
15. Related Parties27
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations27
Item 3. Quantitative and Qualitative Disclosures About Market Risk37
Item 4. Controls and Procedures37
Part II. Other Information37
Item 1. Legal Proceedings37
Item 1A. Risk Factors37
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds37
Item 5. Other Information37
Item 6. Exhibits38
Signatures38

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DEFINITIONS

The following abbreviations or acronyms used in this report are defined below:

Abbreviation or AcronymDefinitionAbbreviation or AcronymDefinition
2022 Form 10-KCombined Annual Report on Form 10-K filed by Alliant Energy, IPL and WPL for the year ended Dec. 31, 2022IUBIowa Utilities Board
AEFAlliant Energy Finance, LLCMDAManagement’s Discussion and Analysis of Financial Condition and Results of Operations
AFUDCAllowance for funds used during constructionMISOMidcontinent Independent System Operator, Inc.
Alliant EnergyAlliant Energy CorporationMWMegawatt
ATCAmerican Transmission Company LLCMWhMegawatt-hour
ATC HoldingsInterest in American Transmission Company LLC and ATC Holdco LLCN/ANot applicable
Corporate ServicesAlliant Energy Corporate Services, Inc.Note(s)Combined Notes to Condensed Consolidated Financial Statements
DthDekathermOPEBOther postretirement benefits
EGUElectric generating unitPPAPurchased power agreement
EPAU.S. Environmental Protection AgencyPSCWPublic Service Commission of Wisconsin
EPSEarnings per weighted average common shareSECSecurities and Exchange Commission
Financial StatementsCondensed Consolidated Financial StatementsU.S.United States of America
FTRFinancial transmission rightWest RiversideWest Riverside Energy Center and Solar Facility
GAAPU.S. generally accepted accounting principlesWhiting 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 cybersecurity incidents or attacks on Alliant Energy, IPL, WPL, or their suppliers, contractors and partners, or responses to such incidents;

  • 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;

  • inflation 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 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 obtain regulatory approval for construction projects with acceptable conditions;

  • the ability to complete 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, project costs and the level of electricity output generated by qualifying generating facilities, and the ability to efficiently utilize the renewable generation and storage project tax benefits for the benefit of customers;

  • the ability to utilize tax credits generated 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, adjustments made to deferred tax assets and liabilities, and changes impacting the availability of renewable tax credits;

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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;

  • 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 energy markets and fuel suppliers and transporters;

  • 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;

  • impacts that terrorist attacks may have on Alliant Energy’s, IPL’s and WPL’s operations and recovery of costs associated with restoration activities, or on the operations of Alliant Energy’s investments;

  • any 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 results of utility operations;

  • continued access to the capital markets on competitive terms and rates, and the actions of credit rating agencies;

  • changes to 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 all environmental and emissions permits and future changes in environmental laws and regulations, including changes to the Coal Combustion Residuals Rule, Cross-State Air Pollution Rule and federal, state or local regulations for greenhouse 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 and state natural resources agencies, or third parties, such as the Sierra Club, and the impact on operating expenses of defending and resolving such claims;

  • 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, 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, wildfires, 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, allocation of mixed service costs and state depreciation, and recoverability of the associated regulatory assets from customers, when the differences reverse in future periods;

  • 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;

  • the effect of accounting standards issued periodically by standard-setting bodies;

  • the ability to successfully complete tax audits and changes in tax accounting methods with no material impact on earnings and cash flows; and

  • 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 Nine Months
Ended September 30,Ended September 30,
2023202220232022
(in millions, except per share amounts)
Revenues:
Electric utility$995$1,039$2,562$2,624
Gas utility4762400418
Other utility13113835
Non-utility22236670
Total revenues1,0771,1353,0663,147
Operating expenses:
Electric production fuel and purchased power231274553633
Electric transmission service154157438428
Cost of gas sold1226226242
Other operation and maintenance160172499492
Depreciation and amortization170169503501
Taxes other than income taxes28288782
Total operating expenses7558262,3062,378
Operating income322309760769
Other (income) and deductions:
Interest expense9983289235
Equity income from unconsolidated investments, net(14)(5)(45)(37)
Allowance for funds used during construction(28)(10)(71)(34)
Other1—2—
Total other (income) and deductions5868175164
Income before income taxes264241585605
Income tax expense514326
Net income attributable to Alliant Energy common shareowners$259$227$582$579
Weighted average number of common shares outstanding:
Basic253.5251.0252.1250.8
Diluted253.8251.3252.4251.1
Earnings per weighted average common share attributable to Alliant Energy common shareowners (basic and diluted)$1.02$0.90$2.31$2.31

Refer to accompanying Combined Notes to Condensed Consolidated Financial Statements.

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ALLIANT ENERGY CORPORATION

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED)

September 30, 2023December 31, 2022
(in millions, except per share and share amounts)
ASSETS
Current assets:
Cash and cash equivalents$206$20
Accounts receivable, less allowance for expected credit losses486516
Production fuel, at weighted average cost4453
Gas stored underground, at weighted average cost87132
Materials and supplies, at weighted average cost196140
Regulatory assets179166
Other174223
Total current assets1,3721,250
Property, plant and equipment, net16,63316,247
Investments:
ATC Holdings380358
Other214201
Total investments594559
Other assets:
Regulatory assets2,0901,880
Deferred charges and other215227
Total other assets2,3052,107
Total assets$20,904$20,163
LIABILITIES AND EQUITY
Current liabilities:
Current maturities of long-term debt$409$408

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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 2022 Form 10-K. Unless otherwise noted, all “per share” references in MDA refer to earnings per diluted share.

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2023 HIGHLIGHTS

Key highlights since the filing of the 2022 Form 10-K include the following:

Customer Investments:

  • In 2021, IPL filed for advance rate-making principles with the IUB for up to 400 MW of solar generation and 75 MW of battery storage. In April 2023, the IUB approved advance rate-making principles for up 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. In May 2023, IPL requested reconsideration of certain ratemaking principles for the up to 200 MW of solar generation, including the cost target and return on common equity. In June 2023, IPL and the IUB filed a joint motion for remand of the other 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 400 MW of solar generation and 75 MW of battery storage. In October 2023, the IUB issued an order approving a modified non-unanimous settlement agreement with the Iowa Office of Consumer Advocate among other stakeholders, for up to 400 MW of solar generation, subject to a cost target of $1,650/kilowatt, including AFUDC and transmission upgrade costs among other costs, and a related return on common equity of no less than 10.25% with the opportunity to request a higher return on common equity in future IPL retail electric rate review filings. Any reasonable and prudent costs incurred in excess of the cost target are eligible for recovery at the return on common equity determined in IPL retail electric rate review filings. The IUB’s order also included a consumer protection plan, which monitors IPL’s achievement of certain aggregate summer capacity factors for the up to 400 MW of solar generation projects during June, July and August each calendar year over 30 years. Actual three-year rolling average summer capacity factors will be compared to target capacity factors, which may result in surpluses or deficits that would be offset against one another and contribute to an accumulated balance in a given calendar year. Surpluses or deficits will be capped at $3 million in aggregate per year. At the end of the program, any accumulated deficit balance would be addressed in IPL’s next rate review, and any accumulated surplus balance would not result in any return to IPL. In November 2023, IPL accepted these advance rate-making principles.

  • In October 2023, WPL received an oral decision from the PSCW authorizing WPL to construct, own and operate approximately 99 MW of battery storage at the Edgewater Generating Station.

  • In August 2023, WPL received an order from the 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.

  • In June 2023, WPL filed requests with the PSCW for approval to construct improvements at the natural gas-fired Neenah Energy Facility and Sheboygan Falls Energy Facility, which would increase the capacity and efficiency of the EGUs. A decision from the PSCW is currently expected by the second quarter of 2024.

  • In April 2023, the IUB issued a certificate of public convenience, use and necessity (GCU Certificate) granting IPL approval to construct, own and operate up to 150 MW of solar generation and up to 75 MW of battery storage at the Wever project in Lee County, Iowa. In March 2023, the IUB issued a 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 Creston project in Union County, Iowa. These solar projects are included in the IUB’s October 2023 order approving advance rate-making principles for up to 400 MW of solar generation.

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 currently expected by the end of 2023.

  • In October 2023, IPL filed a retail electric and gas rate review with the IUB for the October 2024 through September 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 repowering of the existing Franklin County wind farm. The filing requested approval for IPL to implement increases in annual rates for its retail electric and gas customers of $160 million and $14 million, respectively, with any granted rate changes expected to be effective on October 1, 2024. IPL’s filing also requested approval to implement an additional $124 million increase in annual rates for its retail electric customers in 2025, with any granted rate changes expected to be effective on October 1, 2025. IPL also requested a return on common equity of 10% and a 52% common equity component of its regulatory capital structure, as well as to receive continued recovery of and a return on the remaining net book value of the Lansing Generating Station through 2037, which was retired in May 2023. A decision from the IUB is currently expected by the third quarter of 2024.

  • In August 2023, the PSCW authorized WPL to collect $117 million in higher rates, plus interest, from its retail electric customers from October 2023 through December 2025 for fuel-related costs incurred by WPL in 2022 that were higher than fuel-related costs used to determine rates for such period.

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Legislative Matters:

  • Refer to Note 9 for discussion of the Iowa corpo

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Item 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Quantitative and Qualitative Disclosures About Market Risk are reported in the 2022 Form 10-K and 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, as amended) as of September 30, 2023 pursuant to the requirements of the Securities Exchange Act of 1934, as amended. Based on their evaluation, the Chief Executive Officers 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 September 30, 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 September 30, 2023 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 2022 Form 10-K have not changed materially.

ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES, USE OF PROCEEDS AND ISSUER PURCHASES OF EQUITY SECURITIES

A summary of Alliant Energy common stock repurchases for the quarter ended September 30, 2023 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)
July 1 through July 316,298$52.95—N/A
August 1 through August 313,72450.31—N/A
September 1 through September 303849.97—N/A
10,06051.97—

(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 September 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.

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Item 6. EXHIBITS

The following Exhibits are filed herewith or incorporated herein by reference.

Exhibit NumberDescription
4.1Officer’s Certificate, dated as of September 21, 2023, creating IPL’s 5.70% Senior Debentures due October 15, 2033 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed September 21, 2023 (File No. 1-4117))
31.1Certification of the Chief Executive Officer for Alliant Energy
31.2Certification of the Chief Financial Officer for Alliant Energy
31.3Certification of the Chief Executive Officer for IPL
31.4Certification of the Chief Financial Officer for IPL
31.5Certification of the Chief Executive Officer for WPL
31.6Certification of the Chief Financial Officer for WPL
32.1Written Statement of the Chief Executive Officer and Chief Financial Officer Pursuant to 18 U.S.C.§1350 for Alliant Energy
32.2Written Statement of the Chief Executive Officer and Chief Financial Officer Pursuant to 18 U.S.C.§1350 for IPL
32.3Written Statement of the Chief Executive Officer and Chief Financial Officer Pursuant to 18 U.S.C.§1350 for WPL
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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
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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 3rd day of November 2023.

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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