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 the evolving expectations of customers while providing an attractive return for investors, and pursuing emerging technologies and safe, sustainable methods of 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 Clean Energy Blueprint, also known as the roadmap for its transition to cleaner energy, continues to add clean energy resources in Iowa and Wisconsin. As a result, Alliant Energy directly reinvests in the communities it serves through the addition of skilled jobs, economic development and increased tax revenue. In Wisconsin, WPL completed 639 MW of solar generation in 2023, adding to the 250 MW of solar generation placed in service in 2022, and expects to add another 200 MW of solar generation in 2024, resulting in approximately 1,100 MW of solar generation resources in aggregate. In Iowa, IPL expects to complete 400 MW of solar generation by the end of 2024. Completion of these projects is expected to result in approximately 1,500 MW of additional zero-fuel cost solar generation resources for Alliant Energy in aggregate by the end of 2024. The execution of Alliant Energy’s strategy is expected to result in cost benefits for its utility customers by continuing to add renewable energy projects that generate fuel cost benefits and renewable tax credits that are provided to its electric customers.

•Alliant Energy, IPL and WPL currently expect to utilize various provisions of the Inflation Reduction Act of 2022 to enhance tax benefits expected from wind, solar and battery 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, battery storage and wind repowering projects. Refer to Note 1(c) for discussion of $98 million of proceeds from renewable tax credits transferred to other corporate taxpayers in 2023.

•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 maintaining flat base rates for its retail electric and gas customers in 2021, 2022 and 2023.

•Significant fuel cost reductions achieved in 2021, 2022 and 2023 as a result of shortening the term of IPL’s DAEC PPA by 5 years, and beginning in 2023 with the May 2023 retirement of Lansing.

•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.

•In 2023, the U.S. Department of Energy Office of Clean Energy selected the Columbia Energy Storage Project, a first of its kind in the U.S., 20 MW CO2-based long-duration energy storage system at the retiring coal-fired Columbia site, for award negotiations to receive up to $30 million in grant funding. Alliant Energy, with support from various project partners, currently expects to submit project plans to the PSCW in 2024 after award negotiations with the DOE are finished. Any grant proceeds would reduce the cost of the project for WPL’s customers.

•Levelized cost recovery mechanism for the remaining net book value of Edgewater Unit 5, which helps reduce customer costs.

Making customer-focused investments -Alliant Energy’s strategic priorities include making significant customer-focused investments toward cleaner and 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 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) -

•Development and acquisition of additional renewable energy, including approximately 1,100 MW of solar generation at WPL with in-service dates in 2022-2024, approximately 275 MW of battery storage at WPL with in-service dates in 2024 and 2025, and approximately 400 MW of solar generation at IPL with in-service dates in 2024. In addition, IPL and WPL continue to evaluate additional opportunities to add more renewable generation, including repowering of existing wind farms and additional solar generation and distributed energy resources, including community solar and small-scale energy storage systems.

•Plans to construct and/or acquire additional renewable, battery and natural gas resources to meet the requirements of MISO’s seasonal resource adequacy process establishing capacity planning reserve margin and capacity accreditation requirements effective with the 2023/2024 MISO Planning Year.

•Requested PSCW 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.

•Improving reliability and resiliency with more underground electric distribution, and enabling distributed energy solutions with higher capacity lines. Currently, approximately 27% of Alliant Energy’s electric distribution system is underground.

•Alliant Energy continues to partner with its commercial and industrial customers to help develop renewable solutions to enhance their sustainability initiatives, including various customer- and community-hosted solar facilities in Iowa and Wisconsin. Four such facilities were completed in Wisconsin in 2021 and 2022, and several more are currently planned to be completed in 2024 in Iowa and Wisconsin.

•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.

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 -

•Alliant’s Energy was named a Top Utility in Economic Development by Site Selection Magazine for the fifth year in a row, and was named a Top Utility by Business Facilities Magazine for the fourth year in a row.

•Alliant Energy has various development-ready sites throughout Iowa and Wisconsin, including the 1,300-acre Big Cedar Industrial Center Mega-site in Cedar Rapids, Iowa, and the 465-acre Prairie View Industrial Center Super Park in Ames, Iowa, which are rail-served, ready-to-build manufacturing and industrial sites in close proximity to the regional airport, interstate freeways and IPL’s electric services. The Big Cedar Industrial Center Mega-site also accesses Travero’s rail-served warehouse in Iowa. In addition, the Beaver Dam Commerce Park is a 520-acre ready-to-build manufacturing and industrial site in Beaver Dam, Wisconsin, with access to commercial and freight airports, interstate freeways and WPL’s electric services.

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 were as follows (dollars in millions, except per share amounts):

Alliant Energy’s Utilities and Corporate Services net income increased by $34 million in 2023 compared to 2022. The increase was primarily due to higher revenue requirements and AFUDC from capital investments and lower other operation and maintenance expenses at IPL and WPL. These items were partially offset by higher interest expense, lower retail electric and gas sales primarily due to temperature impacts, and higher depreciation expense.

Alliant Energy’s Non-utility and Parent net income decreased by $23 million in 2023 compared to 2022, primarily due to higher interest expense.

Net Income Variances -The following items contributed to increased (decreased) net income for 2023 compared to 2022 (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 and gas sales volumes decreased 2% and 16%, respectively, in 2023 compared to 2022, primarily due to changes in temperatures.

Estimated increases (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 2023 compared to 2022 (in millions):

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

(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 $6 million and ($6) million in 2023 and 2022, respectively. Refer to Note 2 for discussion of deferred fuel-related costs that were outside the approved fuel monitoring range in 2023, 2022 and 2021.

Gas Utility Revenue Variances -The following items contributed to increased (decreased) gas utility revenues for 2023 compared to 2022 (in millions):

(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.

Electric Production Fuel and Purchased Power Expenses Variances -The following items contributed to (increased) decreased electric production fuel and purchased power expenses for 2023 compared to 2022 (in millions):

(a)Electric production fuel costs decreased primarily due to lower natural gas prices in 2023 compared to 2022 and lower coal volumes utilized due to IPL’s retirement of Lansing in May 2023, partially offset by higher natural gas volumes due to higher dispatch of IPL’s and WPL’s natural gas-fired EGUs in 2023.

(b)Purchased power expense decreased primarily due to lower prices for electricity purchased by IPL and WPL from MISO wholesale energy markets, and decreased volumes of electricity purchased due to lower retail and wholesale electric sales and less reliance on wholesale energy market purchases due to higher dispatch of IPL’s and WPL’s natural gas-fired EGUs.

Electric Transmission Service Expense Variances -The following items contributed to (increased) decreased electric transmission service expense for 2023 compared to 2022 (in millions):

Cost of Gas Sold Expense Variances -The following items contributed to (increased) decreased cost of gas sold expense for 2023 compared to 2022 (in millions):

Other Operation and Maintenance Expenses Variances - The following items contributed to (increased) decreased other operation and maintenance expenses for 2023 compared to 2022 (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 2024 through its Shareowner Direct Plan. IPL, WPL and AEF currently expect to issue up to $700 million, $300 million and $700 million of long-term debt, respectively, in 2024. IPL and AEF have $500 million and $300 million of long-term debt, respectively, maturing in 2024.

•Common Stock Dividends -Alliant Energy announced a 6% increase in its targeted 2024 annual common stock dividend to $1.92 per share, which is equivalent to a quarterly rate of $0.48 per share, beginning with the February 2024 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.

•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 and WPL currently expect an increase in future cash flows from operating activities resulting from higher earnings on increasing rate base at WPL.

•IPL’s Electric Sales Trends -In July 2025, IPL’s wholesale power agreement with Southern Minnesota Energy Cooperative will expire. Sales to Southern Minnesota Energy Cooperative represented approximately 5% of IPL's total electric sales in 2023.

•Higher Earnings on Increasing Rate Base -Alliant Energy and WPL currently expect an increase in earnings in 2024 compared to 2023 due to impacts from increasing revenue requirements related to investments in the utility business.

•Depreciation and Amortization Expense - Alliant Energy, IPL and WPL currently expect an increase in depreciation and amortization expense in 2024 compared to 2023 due to capital projects placed in service in 2023 and 2024 and lower amortization of WPL’s West Riverside liquidated damages. Refer to Note 2 for discussion of WPL’s West Riverside liquidated damages.

•Interest Expense -Alliant Energy, IPL and WPL currently expect an increase in interest expense in 2024 compared to 2023 due to financings completed in 2023 and planned in 2024 as discussed above.

•AFUDC - Alliant Energy and WPL currently expect a decrease and IPL currently expects an increase in AFUDC in 2024 compared to 2023 largely due to changes in CWIP balances related to construction activity on capital projects.