ALLIANT ENERGY CORP

Mission, Purpose and Strategy

Alliant Energy’s mission is to deliver affordable energy solutions and exceptional service that its customers and the communities it serves count on - affordably, safely, reliably, and sustainably. This mission aligns with Alliant Energy’s purpose - to serve customers and build stronger communities - which guides it through the ever-changing dynamics of the economy and the energy industry. Alliant Energy takes its responsibility as a corporate citizen seriously and remains a careful steward of the environment and supports the communities in its service territories. Alliant Energy’s mission and purpose are supported by a strategy focused on meeting evolving customer expectations, providing an attractive return for investors, and advancing emerging technologies with safe, secure energy production. This strategy includes the following key elements:

Providing affordable energy solutions for customers -Alliant Energy’s strategy focuses on affordable energy solutions that support retention and growth of its existing customers and attract new customers to its service territories.

Key Highlights -

•Alliant Energy’s resource plan continues to add resources in Iowa and Wisconsin, which is expected to result in continued reliability and affordability for its utility customers. As a result, Alliant Energy directly reinvests in the communities it serves through the addition of skilled jobs, economic development and increased tax revenue. From 2022 through 2024, Alliant Energy completed projects that resulted in approximately 1,500 MW of additional zero-fuel cost solar generation resources in aggregate (WPL completed 1,089 MW of solar generation in Wisconsin in 2022-2024 and IPL completed 400 MW of solar generation in Iowa in 2024), which generate renewable tax credits that are provided to its electric customers.

•Alliant Energy, IPL and WPL have utilized, and expect to continue to utilize, various provisions of the Inflation Reduction Act of 2022 to enhance tax benefits expected from wind, solar and energy storage projects in Iowa and Wisconsin, including transferring certain future tax credits from such projects to other corporate taxpayers. The Inflation Reduction Act of 2022 is expected to result in more cost benefits for IPL’s and WPL’s customers, higher rate base amounts, and improvements in long-term cash flows over the life of the solar, energy storage and wind refurbishment projects. Refer to Note 1(c) for discussion of $216 million and $98 million of proceeds from renewable tax credits transferred to other corporate taxpayers in 2024 and 2023, respectively.

•Reductions in Iowa corporate income tax rates resulting from tax reform enacted in 2022 are expected to provide cost benefits to IPL’s electric and gas customers in the future. IPL’s retail electric and gas customers began receiving these benefits with the new base rates effective October 1, 2024.

•IPL maintaining flat base rates for its retail electric and gas customers from 2021 through September 30, 2024, as well as a retail electric base rate moratorium from October 2025 through September 2029 approved by the IUC in IPL’s most recent retail electric rate review.

•Significant fuel cost reductions beginning in 2023 with the completion of various solar facilities.

•Completion of a restructuring and voluntary employee separation program in 2024, which is expected to reduce operation and maintenance expenses in the future.

•Issuance of new long-term debt at historically low interest rates for IPL ($300 million of 3.1% senior debentures due 2051) and WPL ($300 million of 1.95% green bonds due 2031) in 2021 and WPL ($600 million of 3.95% green bonds due 2032) in 2022.

•IPL and WPL have entered into conditional commitments with the U.S. Department of Energy’s Loan Programs Office for loan guarantees of approximately $1.4 billion and $1.6 billion, respectively. If finalized, such loans would provide low interest financing for IPL’s and WPL’s expected construction of renewable generation and energy storage projects.

•In July 2024, the U.S. Department of Energy Office of Clean Energy Demonstrations awarded WPL’s Columbia Energy Storage Project, an approximately 20 MW compressed CO2-based long-duration energy storage system at the Columbia Energy Center site, up to approximately $30 million in grant funding during construction of the project. In addition, in October 2024, the U.S. Department of Energy Office of Grid Deployment selected WPL’s Smart Power Automation for Rural Communities program application to move into the final stage of award negotiations for up to $50 million in grant funding under the Grid Resilience and Innovation Partnerships Program. If finalized, any grant proceeds would reduce the cost of the projects for WPL’s customers.

Making customer-focused investments -Alliant Energy’s strategic priorities include making significant customer-focused investments toward more reliable, resilient, and sustainable customer energy solutions. Alliant Energy’s strategy drives a capital allocation process focused on: 1) transitioning its generation portfolio to meet the growing interest and needs of customers for reliable and sustainable sources of energy, 2) upgrading its electric and gas distribution systems to strengthen safety, reliability and resiliency, as well as enable distributed energy solutions in its service territories, and 3) enhancing its customers’ and employees’ experience with evolving technology and greater flexibility.

Key Highlights (refer to “Customer Investments” for details) -

•Over the next five years, Alliant Energy currently plans to develop and/or acquire new generation investments to add flexibility with evolving load growth, including approximately 1,200 MW of new wind and solar generation in aggregate, approximately 1,000 MW of energy storage, approximately 750 MW of new natural gas resources, refurbishments at approximately 600 MW of existing wind farms, and improvements at approximately 650 MW of existing natural gas-fired EGUs and the conversion of existing coal-fired EGUs to natural gas. Alliant Energy is currently evaluating the impact of potential additional large load growth customers and MISO’s seasonal resource adequacy requirements on its resource plans and will update these generation investment plans as needed in the future.

•Completion of new solar generation at WPL (1,089 MW in Wisconsin from 2022-2024) and IPL (400 MW in Iowa in 2024), and IPL’s refurbishment of the existing Franklin County wind farm in Iowa in 2024.

•Improving reliability and resiliency with more underground electric distribution, and enabling distributed energy solutions with higher capacity lines. Currently, approximately 28% of Alliant Energy’s electric distribution system is underground.

•Alliant Energy continues to partner with its commercial and industrial customers in Iowa and Wisconsin to help develop renewable solutions to support their sustainability initiatives.

•Installing fiber optic routes between Alliant Energy’s facilities to enhance its communications network to improve resiliency and reliability of, and enable and strengthen, the integrated grid network focused on less densely populated rural areas. Currently, approximately 1,000 miles of underground fiber optic routes have been installed.

Growing customer demand -Alliant Energy’s strategy supports expanding electric and gas usage in its service territories by promoting electrification initiatives and economic development.

Key Highlights -

•The IUC’s order for IPL’s most recent retail electric rate review includes the creation of an individual customer rate tariff, allowing IPL to attract new load growth to its service territory. In addition, Iowa’s Major Economic Growth Attraction program and Wisconsin’s sales and use tax exemption for qualified data centers, encourage economic development in Alliant Energy’s service territory.

•IPL has entered into electric service agreements with two new customers, who currently expect to build data centers at the Big Cedar Industrial Center in Cedar Rapids, Iowa in IPL’s service territory. These agreements include aggregate, maximum demands of approximately 1.9 gigawatts. The electric service agreements are subject to IUC approval under the individual customer rate tariff that was included in the IUC’s September 2024 order for IPL’s retail electric rate review. The actual timing and amount of increases in IPL’s load are subject to various factors, including interconnections and actual customer demand, and any executed or future agreements with customers are not expected to result in immediate increases in load.

•Various development-ready sites, which are rail-served and in close proximity to a variety of transportation options, are located throughout Alliant Energy’s service territories.

Financial Results Overview -The table below includes diluted 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 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 were as follows (dollars in millions, except per share amounts):

Alliant Energy’s Utilities and Corporate Services net income decreased by $2 million in 2024 compared to 2023. The decrease was primarily due to an asset valuation charge for IPL’s Lansing Generating Station as a result of the IUC order for IPL’s retail electric rate review, estimated temperature impacts on retail electric and gas sales, restructuring and voluntary separation charges, an ARO charge allocated to the steam business at IPL due to the revised CCR Rule, higher depreciation and financing expenses, and lower AFUDC. These items were partially offset by higher revenue requirements from capital investments.

Alliant Energy’s Non-utility and Parent net income decreased by $16 million in 2024 compared to 2023, primarily due to higher financing expense.

Net Income Variances -The following items contributed to increased (decreased) net income for 2024 compared to 2023 (in millions):

Electric and Gas Revenues and Sales Summary -Electric and gas revenues (in millions), and MWh and Dth sales (in thousands), were as follows:

Sales Trends and Temperatures - Alliant Energy’s retail electric sales volumes decreased 1% in 2024 compared to 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 decreased 6% in 2024 compared to 2023, primarily due to changes in temperatures.

Estimated decreases to operating income from the impacts of temperatures 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 2024 compared to 2023 (in millions):

(a)In September 2024, the IUC issued an order authorizing an annual base rate increase of $185 million for IPL’s retail electric customers, with customers receiving partially offsetting credits for the first 12 months through a tax benefit rider, for the October 2024 through September 2025 forward-looking Test Period. Rate changes were effective October 1, 2024, which reflect revenue requirement impacts of increasing electric rate base including investments in solar generation, updated depreciation rates, and certain incremental costs incurred resulting from the 2020 derecho windstorm. In addition, effective October 1, 2024, IPL’s renewable energy rider was discontinued, and certain production tax credits are credited to IPL’s retail electric customers through IPL’s fuel-related cost recovery mechanism. Credits on IPL’s customers’ bills are expected to be offset by a reduction in income tax expense.

(b)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.

(c)Alliant Energy’s and WPL’s sales for resale bulk power and other revenues increased primarily due to higher volumes and higher prices for electricity sold by WPL to MISO wholesale energy markets. Alliant Energy’s increase was partially offset by decreased sales for resale bulk power and other revenues at IPL primarily due to lower prices for electricity and capacity sold by IPL to MISO wholesale energy markets. These changes were largely offset by changes in fuel-related costs.

(d)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 ($4) million and $6 million in 2024 and 2023, respectively.

Gas Utility Revenue Variances -The following items contributed to increased (decreased) gas utility revenues for 2024 compared to 2023 (in millions):

(a)In September 2024, the IUC issued an order authorizing an annual base rate increase of $10 million for IPL’s retail gas customers, for the October 2024 through September 2025 forward-looking Test Period. Rate changes were effective October 1, 2024, which reflect revenue requirement impacts of increasing gas rate base.

(b)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 2024 compared to 2023 (in millions):

(a)Electric production fuel costs decreased at IPL primarily due to lower natural gas prices in 2024 compared to 2023, and lower natural gas and coal volumes due to lower dispatch of IPL’s EGUs in 2024. Electric production fuel costs decreased at WPL primarily due to lower natural gas prices in 2024 compared to 2023, and higher dispatch of WPL’s renewable EGUs in 2024, partially offset by higher coal volumes due to higher dispatch of WPL’s coal-fired EGU’s in 2024.

(b)Purchased power expense increased primarily due to higher prices for electricity purchased by IPL and WPL, and higher volumes of electricity purchased at IPL due to lower dispatch of IPL’s EGUs in 2024, partially offset by lower volumes of electricity purchased at WPL due to higher dispatch of WPL’s EGUs in 2024.

Electric Transmission Service Expense Variances -The following items contributed to (increased) decreased electric transmission service expense for 2024 compared to 2023 (in millions):

Cost of Gas Sold Expense Variances -The following items contributed to (increased) decreased cost of gas sold expense for 2024 compared to 2023 (in millions):

Other Operation and Maintenance Expenses Variances - The following items contributed to (increased) decreased other operation and maintenance expenses for 2024 compared to 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.

•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 tax credits from renewable generation and energy storage projects placed in service in 2024 and/or 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 energy 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 “Rate Matters.”

•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 2024), which is not expected to have a material impact on Alliant Energy’s or IPL’s future financial condition and results of operations. In 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, charges for restructuring and voluntary employee separation recorded in 2024, as well as expected future cost 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, and updated electric depreciation rates for IPL effective October 1, 2024.

•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.