ALLIANT ENERGY CORP

RESULTS OF OPERATIONS

Financial Results Overview -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. Alliant Energy’s net income and EPS attributable to Alliant Energy common shareowners for the three months ended September 30 were as follows (dollars in millions, except per share amounts):

Alliant Energy’s Utilities and Corporate Services net income increased by $27 million for the three-month period, primarily due to higher revenue requirements from WPL’s capital investments and the timing of income taxes. These items were partially offset by higher financing and depreciation expenses, and estimated temperature impacts on retail electric and gas sales.

Alliant Energy’s Non-utility and Parent net income increased $9 million for the three-month period, primarily due to charges related to the remeasurement of deferred tax assets due to Iowa corporate income tax rate changes recorded in the third quarter of 2023.

Net Income Variances -The following items contributed to increased (decreased) net income for the three and nine months ended September 30, 2024 compared to the same periods in 2023 (in millions):

Electric and Gas Revenues and Sales Summary -Electric and gas revenues (in millions), and MWh and Dth sales (in thousands), for the three and nine months ended September 30 were as follows:

Sales Trends and Temperatures - Alliant Energy’s retail electric sales volumes decreased 2% for boththe three and nine months ended September 30, 2024, compared to the same periods in 2023, primarily due to changes in sales volumes at IPL’s industrial customers due to standby service customers that can use other generation and changes in temperatures. Alliant Energy’s retail gas sales volumes were unchanged and decreased 9% for the three and nine months ended September 30, 2024, respectively, compared to the same periods in 2023, primarily due to changes in temperatures.

Estimated increases (decreases) to operating income from the impacts of temperatures for the three and nine months ended September 30 were as follows (in millions):

Electric Sales for Resale - Bulk Power and Other -Bulk power and other volume changes were 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 bulk power and other revenues were largely offset by changes in fuel-related costs, and therefore did not have a significant impact on operating income.

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.

Electric Utility Revenue Variances -The following items contributed to increased (decreased) electric utility revenues for the three and nine months ended September 30, 2024 compared to the same periods in 2023 (in millions):

(a)In December 2023, the PSCW issued an order authorizing an annual base rate increase of $49 million for WPL’s retail electric customers, covering the 2024 forward-looking Test Period, which reflects revenue requirement impacts of increasing electric rate base and lower forecasted fuel-related expenses.

(b)WPL’s cost recovery mechanism for retail fuel-related expenses supports deferrals of amounts that fall outside an approved fuel monitoring range of forecasted fuel-related expenses determined by the PSCW each year. The difference between revenue collected and actual fuel-related expenses incurred within the fuel monitoring range increases or decreases Alliant Energy’s and WPL’s electric utility revenues. WPL estimates the increase (decrease) to electric utility revenues from amounts within the fuel monitoring range were approximately $0 and ($4) million for the three and nine months ended September 30, 2024, respectively, compared to $2 million and $5 million for the three and nine months ended September 30, 2023, respectively.

Gas Utility Revenue Variances -The following items contributed to increased (decreased) gas utility revenues for the three and nine months ended September 30, 2024 compared to the same periods in 2023 (in millions):

(a)In December 2023, the PSCW issued an order authorizing an annual base rate increase of $13 million for WPL’s retail gas customers, covering the 2024 forward-looking Test Period, which reflects revenue requirement impacts of increasing gas rate base.

Electric Production Fuel and Purchased Power Expenses Variances -The following items contributed to (increased) decreased electric production fuel and purchased power expenses for the three and nine months ended September 30, 2024 compared to the same periods in 2023 (in millions):

(a)Electric production fuel costs decreased for the three and nine months ended September 30, 2024, compared to the same periods in 2023, primarily due to lower natural gas prices at IPL and WPL, and lower coal volumes at IPL due to lower dispatch of IPL’s coal-fired EGUs in 2024. Also contributing to the three-month decrease were lower coal volumes at WPL due to lower dispatch of WPL’s coal-fired EGUs in the third quarter of 2024. Also contributing to the nine-month decrease were lower natural gas volumes at IPL due to lower dispatch of IPL’s natural gas-fired EGUs in 2024.

(b)Purchased power expense increased for the nine months ended September 30, 2024, compared to the same period in 2023, primarily due to higher prices for electricity purchased by IPL and WPL and increased volumes of electricity purchased at IPL, partially offset by decreased volumes of electricity purchased at WPL.

Electric Transmission Service Expense Variances -The following items contributed to (increased) decreased electric transmission service expense for the three and nine months ended September 30, 2024 compared to the same periods in 2023 (in millions):

Cost of Gas Sold Expense Variances -The following items contributed to (increased) decreased cost of gas sold expense for the three and nine months ended September 30, 2024 compared to the same periods in 2023 (in millions):

Other Operation and Maintenance Expenses Variances -The following items contributed to (increased) decreased other operation and maintenance expenses for the three and nine months ended September 30, 2024 compared to the same periods in 2023 (in millions):

Other Future Considerations - In addition to items discussed in this report, the following key items could impact Alliant Energy’s, IPL’s and WPL’s future financial condition or results of operations:

•Financing Plans- Alliant Energy currently expects to issue up to $25 million of common stock in 2025 through its Shareowner Direct Plan. In 2025, IPL currently expects to issue up to $600 million of long-term debt, and AEF and/or Alliant Energy at the parent company level expect to issue up to $600 million of long-term debt in aggregate. IPL and AEF each have $300 million of long-term debt maturing in 2025.

•Common Stock Dividends- Alliant Energy announced a 6% increase in its targeted 2025 annual common stock dividend to $2.03 per share, which is equivalent to a quarterly rate of $0.5075 per share, beginning with the February 2025 dividend payment. The timing and amount of future dividends is subject to approval of quarterly dividend declarations from Alliant Energy’s Board of Directors, and is dependent upon earnings expectations, capital requirements, and general financial business conditions, among other factors.

•Restructuring and Voluntary Employee Separation Charges -In the fourth quarter of 2024, Alliant Energy announced restructuring activities, including offering certain employees a voluntary separation package to help align resources with evolving business and customer needs, and reduce customer costs. Approximately 5% of Alliant Energy employees accepted the package, and as a result of the announced restructuring activities, Alliant Energy currently expects to record pre-tax charges of $25 million to $30 million in the fourth quarter of 2024.

•Cash Flows From Operating Activities- Alliant Energy, IPL and WPL currently expect an increase in future cash flows from operating activities resulting from the transfer of future renewable tax credits to other corporate taxpayers pursuant to the Inflation Reduction Act of 2022. In addition, Alliant Energy, IPL and WPL currently expect an increase in future cash flows from operating activities resulting from higher earnings on increasing rate base at IPL and WPL.

•Higher Earnings on Increasing Rate Base- Alliant Energy, IPL and WPL currently expect increases in electric utility and gas utility revenues in 2025 compared to 2024 due to impacts from increasing revenue requirements related to investments in the utility business. In addition, Alliant Energy, IPL and WPL currently expect a decrease in the effective income tax rate in 2025 compared to 2024 due to additional renewable tax credits from renewable generation and battery storage projects placed in service in 2024 and expected to be placed in service in 2025. A majority of the differences between actual renewable tax credits and renewable tax credits used to determine rates are recorded in regulatory assets or regulatory liabilities on the balance sheets until they are reflected in future billings to customers. Investment tax credits resulting from IPL battery storage projects expected to be placed in service in 2025 may be utilized to offset any revenue deficiency on an annual basis up to the earnings sharing mechanism threshold included in IPL’s retail electric rate review settlement agreement discussed in “2024 Highlights.”

•Sales Trends and Temperatures - In July 2025, IPL’s wholesale power agreement with Southern Minnesota Energy Cooperative (SMEC) will expire (sales to SMEC represented approximately 5% of IPL’s total electric sales in 2023), which is not expected to have a material impact on Alliant Energy’s or IPL’s future financial condition and results of operations. For the nine months ended September 30, 2024, warmer than normal temperatures in the winter and cooler than normal temperatures in the summer in Alliant Energy’s, IPL’s and WPL’s service territories resulted in lower retail electric and gas sales volumes and operating income.

•Other Operation and Maintenance Expenses- Alliant Energy, IPL and WPL currently expect a decrease in other operation and maintenance expenses in 2025 compared to 2024 largely due to the asset valuation charge for IPL’s Lansing Generating Station and ARO charge for steam assets at IPL recorded in 2024, and the charges expected to be recorded in the fourth quarter of 2024 and expected future costs savings related to Alliant Energy’s restructuring activities. These items are expected to be partially offset by higher generation maintenance and energy delivery expenses.

•Depreciation and Amortization Expense - Alliant Energy, IPL and WPL currently expect an increase in depreciation and amortization expense in 2025 compared to 2024 due to capital projects placed in service in 2024 and 2025.

•Interest Expense- Alliant Energy, IPL and WPL currently expect an increase in interest expense in 2025 compared to 2024 due to financings completed in 2024 and planned in 2025 as discussed above.

LIQUIDITY AND CAPITAL RESOURCES

The liquidity and capital resources summary included in the 2023 Form 10-K has not changed materially, except as described below.

Liquidity Position -At September 30, 2024, Alliant Energy had $827 million of cash and cash equivalents, $670 million ($120 million at the parent company, $250 million at IPL and $300 million at WPL) of available capacity under the single revolving credit facility and $4 million of available capacity at IPL under its sales of accounts receivable program.

Capital Structure -Capital structures at September 30, 2024 were as follows (Long-term Debt (including current maturities) (LD); Short-term Debt (SD); Common Equity (CE)):

Cash Flows -Selected information from the cash flows statements was as follows (in millions):

Operating Activities -The following items contributed to increased (decreased) operating activity cash flows for the nine months ended September 30, 2024 compared to the same period in 2023 (in millions):

(a)Refer to the cash flows statements for details of renewable tax credits transferred to other corporate taxpayers during the nine months ended September 30, 2024.

Investing Activities - The following items contributed to increased (decreased) investing activity cash flows for the nine months ended September 30, 2024 compared to the same period in 2023 (in millions):

(a)Largely due to higher expenditures for WPL’s battery storage and IPL’s solar generation, partially offset by lower expenditures for WPL’s solar generation.

Construction and Acquisition Expenditures - Construction and acquisition expenditures and financing plans are reviewed, approved and updated as part of the strategic planning process. Changes may result from a number of reasons, including regulatory requirements, changing legislation, not obtaining favorable and acceptable regulatory approval on certain projects, changing costs of projects due to market conditions, changes in expected load growth, improvements in technology, and improvements to ensure resiliency and reliability of the electric and gas distribution systems. Refer to “2024 Highlights” for discussion of an electric distribution system investment cap included in IPL’s rate review settlement agreement, which was approved by the IUC in September 2024. Construction and acquisition expenditures for 2024 through 2028 are currently anticipated as follows (in millions), which are focused on transitioning to cleaner sources of energy, adding generation to meet growing customer demand for electricity, and strengthening the resiliency and reliability of the electric grid, and include renewable generation and battery storage projects, dispatchable gas generation projects, converting certain coal-fired EGUs to natural gas, and wind repowering projects. Cost estimates represent Alliant Energy’s, IPL’s and WPL’s portion of construction expenditures and exclude allowance for funds used during construction and capitalized interest, if applicable.

Financing Activities - The following items contributed to increased (decreased) financing activity cash flows for the nine months ended September 30, 2024 compared to the same period in 2023 (in millions):

Common Stock Issuances and Common Stock Dividends - Refer to Note 6 for discussion of common stock issuances by Alliant Energy in 2024. Refer to “Results of Operations” for discussion of expected future issuances of common stock and common stock dividends in 2025.

Long-term Debt - Refer to Note 7(b) for discussion of various issuances and/or retirements of long-term debt by AEF, IPL and WPL in 2024. Refer to “Results of Operations” for discussion of expected future issuances and retirements of long-term debt in 2025.

Impact of Credit Ratings on Liquidity and Collateral Obligations -

Ratings Triggers - In March 2024, Standard & Poor’s Ratings Services changed Alliant Energy’s and IPL’s outlooks from stable to negative. These outlook changes are not expected to have a material impact on Alliant Energy’s and IPL’s liquidity or collateral obligations.

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 2023 Form 10-K and has not changed materially from the items reported in the 2023 Form 10-K, except for the items described in Notes 4,7 and 14.

OTHER MATTERS

Critical Accounting Estimates -The summary of critical accounting estimates included in the 2023 Form 10-K has not changed materially, except as described below.

Regulatory Assets and Regulatory Liabilities -In May 2023, IPL retired the Lansing Generating Station. IPL was previously allowed a full recovery of and a full return on this EGU from both its retail and wholesale customers. In September 2024, the IUC approved IPL’s June 2024 settlement agreement with certain stakeholders for IPL’s retail electric rate review for the October 2024 through September 2025 forward-looking Test Period. The agreement includes a return of the remaining net book value of Lansing; however, the agreement does not include a return on the remaining net book value of Lansing, therefore the return on the remaining net book value is no longer recoverable from IPL’s retail electric customers. As a result, a pre-tax non-cash charge of $60 million was recorded to “Asset valuation charge for IPL’s Lansing Generating Station” in Alliant Energy’s and IPL’s income statements for the nine months ended September 30, 2024, with a corresponding decrease in Alliant Energy’s and IPL’s assets retired early regulatory assets.

Long-Lived Assets -

Regulated Operations -

Generating Units Subject to Early Retirement - In May 2024, WPL announced updated plans to convert the coal-fired Edgewater Unit 5 to natural gas in 2028, subject to regulatory approvals. WPL previously planned to retire the EGU by June 1, 2025. As a result, Alliant Energy and WPL concluded Edgewater Unit 5 no longer meets the criteria to be considered probable of abandonment as of September 30, 2024. Refer to Note 3 for further discussion of Edgewater Unit 5.

Solar Generation Projects Recently Completed or Under Construction - Alliant Energy and WPL currently expect construction costs associated with WPL’s approximately 1,100 MW of new solar generation will exceed the construction cost estimates previously approved by the PSCW by approximately $195 million. In February 2024, the PSCW issued an order approving deferral of the incremental solar generation construction costs. The PSCW’s order did not authorize a deferral for the return on such costs. In March 2024, WPL filed for judicial review of the PSCW’s retail electric rate review order (2024/2025 forward-looking Test Period) and solar generation construction cost deferral order related to the recovery and deferral of the return on the incremental solar generation construction costs in 2024 and 2025. In September 2024, the PSCW issued an order modifying its February 2024 order and approving the deferral of the return on the incremental solar generation construction costs, and in October 2024, WPL withdrew its filing for judicial review. Alliant Energy and WPL concluded that there was not a probable disallowance of anticipated higher rate base amounts as of September 30, 2024 given construction costs were reasonably and prudently incurred.

In September 2024, the IUC approved IPL’s settlement agreement with certain stakeholders for its retail electric rate review for the October 2024 through September 2025 forward-looking Test Period. The settlement agreement allows IPL to recover construction costs associated with its 400 MW of new solar generation, including allowance for funds used during construction and transmission upgrade costs among other costs, above the original cost target of $1,650/kilowatt up to $1,837.5/kilowatt. The costs up to the original cost target of $1,650/kilowatt will earn a return on common equity of 10.25%. The costs between $1,650/kilowatt and $1,837.5/kilowatt will earn a return on common equity that is the same as other assets without advance rate-making principles, without having to establish that such costs were reasonably and prudently incurred. Alliant Energy and IPL currently do not expect these construction costs will exceed $1,837.5/kilowatt.

AROs -The fair value of a legal obligation associated with the retirement of an asset is recorded as a liability when an asset is placed in service, when a legal obligation is subsequently identified or when sufficient information becomes available to determine a reasonable estimate of the fair value of future retirement costs. Alliant Energy, IPL and WPL estimate the fair value of their AROs using present value techniques, in which they make various assumptions, including estimates of the amounts and timing of future cash flows associated with retirement activities, inflation and discount rates. Estimates of the timing and amounts of future cash outlays are based on projections of when and how assets will be retired and the cost of future removal activities. The estimates are subject to change and future updates could have a material impact on Alliant Energy’s, IPL’s and WPL’s financial condition and results of operations. In the second quarter of 2024, substantially due to the enactment of the revised CCR Rule, which significantly expands the scope of regulation to include coal ash ponds at sites that no longer produce electricity and inactive landfills, Alliant Energy, IPL and WPL recorded additional AROs of $355 million, $102 million and $253 million, respectively. These amounts are expected to be adjusted in the future as additional information is obtained for the specific site closure plans, including the determination of whether or not individual sites are considered legal obligations and the acceptance and approval of compliance approaches, which could change management assumptions and result in a material change to the recorded ARO amounts. Refer to Note 11 for further discussion of AROs.