ALLIANT ENERGY CORP

Alliant Energy’s, IPL’s and WPL’s strategic priorities include making significant customer-focused investments toward reliable, resilient and sustainable customer energy solutions. These priorities include:

Resource Planning

Alliant Energy’s current resource plan continues to add resources in Iowa and Wisconsin, and serves as a guide to meet customer demand for affordable, safe, reliable and sustainable energy. 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. Estimated capital expenditures for these planned projects for 2025 through 2028 are included in the “Generation” section in the construction and acquisition table in “Liquidity and Capital Resources.” Information on IPL’s and WPL’s regulatory filings and/or approvals for future generation and energy storage projects, as well as recently completed projects, are as follows:

WPL’s Generation and Energy Storage Projects -

Solar - In 2022 through 2024, WPL completed 1,089 MW of new solar generation projects in Wisconsin, including the Grant County facility (200 MW) in 2024. Refer to Note 3 for discussion of the construction costs associated with these projects.

Energy Storage - In 2023, the PSCW issued orders authorizing WPL to construct, own and operate energy storage at the Grant County (100 MW) and Wood County (75 MW) solar projects in Wisconsin, which is currently expected to be placed in service in the second half of 2025, and at the Edgewater Generation Station in Wisconsin (approximately 99 MW), which is currently expected to be placed in service in 2026.

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 August 2024, WPL filed a CA application with the PSCW for construction approval of the energy storage system. A decision from the PSCW is currently expected in the second quarter of 2025. If finalized, any grant proceeds would reduce the cost of the project for WPL’s customers.

Existing Natural Gas-Fired Electric Generating Unit Improvements - In April 2024, the PSCW issued orders authorizing WPL to construct improvements at the existing natural gas-fired Neenah Energy Facility and Sheboygan Falls Energy Facility, which would increase the capacity and efficiency of the EGUs.

Existing Wind Farm Refurbishment - In July 2024, WPL filed a CA application with the PSCW for approval to refurbish the Bent Tree wind farm, which would be eligible for production tax credits under the Inflation Reduction Act of 2022. A decision from the PSCW is currently expected in the first quarter of 2025.

IPL’s Generation and Energy Storage Projects -

Solar - In 2024, IPL completed new solar generation projects in Iowa, including the Wever facility (150 MW), the Creston facility (50 MW), and the first (50 MW) and second (150 MW) phases of the Pleasant Creek facility. Refer to Note 3 for discussion of the construction costs associated with these projects.

Energy Storage - IPL received approval from the IUC to construct, own and operate up to approximately 140 MW of energy storage in Iowa (100 MW at the Wever project and 40 MW at the Creston project), which is currently expected to be placed in service in 2025 and 2026.

Natural Gas-fired Electric Generating Unit - In February 2025, IPL filed request with the IUC for approval to construct, own and operate the Cedar River Generating Station, a 94 MW natural gas-fired EGU using Reciprocating Internal Combustion Engine (RICE) technology, at the site of IPL’s Prairie Creek Generation Station. A decision from the IUC is currently expected in the fourth quarter of 2025.

Existing Wind Farm Refurbishment - In 2024, IPL completed the refurbishment of the existing Franklin County wind farm in Iowa. IPL currently expects the refurbishment of the existing Whispering Willow - East wind farm to be completed in 2026. These projects are eligible for production tax credits under the Inflation Reduction Act of 2022.

WPL’s West Riverside Natural Gas-fired Generating Station -In 2020, WPL completed the construction of West Riverside, a 723 MW natural gas-fired combined-cycle EGU in Beloit, Wisconsin. WPL entered into agreements with neighboring utilities and electric cooperatives that provide each of them options to purchase a partial ownership interest in West Riverside. The purchase price for such options is based on the ownership interest acquired and the net book value of West Riverside on the date of the purchase. The timing and ownership amount of the options are as follows:

(a)WPL may exercise reciprocal options, subject to approval by the PSCW, to purchase up to 200 MW of any natural-gas combined-cycle EGU that WEC places in service prior to May 2030.

Plant Retirements and Fuel Switching -The current strategy includes the retirement, or fuel switch from coal to natural gas, of various EGUs in the next several years. IPL currently expects to retire Prairie Creek Unit 1 and fuel switch Prairie Creek Unit 3 (65 MW in aggregate) by December 31, 2025. WPL currently expects to convert the coal-fired Edgewater Unit 5 (414 MW) to natural gas in 2028. In addition, WPL currently plans to cease coal operations at Columbia Units 1 and 2 (595 MW in aggregate) by the end of 2029, as well as evaluate the conversion of Columbia Unit 1 and/or Unit 2 to natural gas. Alliant Energy, IPL and WPL are working with MISO, state regulatory commissions and other regulatory agencies, as required, to determine the timing of these actions, which are subject to change depending on operational, regulatory, market and other factors. Refer to Note 3 for additional details on Columbia Units 1 and 2, and Edgewater Unit 5.

Environmental Stewardship -Alliant Energy’s environmental stewardship is focused on the implementation of a responsible energy strategy to meet its customers’ energy needs affordably, safely, reliably and sustainably. Alliant Energy periodically reviews and updates this strategy to reflect changes needed to support the transition to a low-carbon economy. Alliant Energy’s current voluntary environmental-related goals and achievements include the following:

•Exceeded its 2020 targets by reducing air emissions for sulfur dioxide by over 90%, nitrogen oxides by over 80% and mercury by over 90% from 2005 levels.

•By 2030, reduce GHG emissions from its utility operations by 50% from 2005 levels, reduce its electric utility water supply by 75% from 2005 levels and electrify 100% of its owned light-duty fleet vehicles.

•By 2040, eliminate all coal-fired EGUs from its generating fleet.

•By 2050, aspire to achieve net-zero GHG emissions from its utility operations.

Alliant Energy’s aspirational GHG goal includes EPA reportable emissions based on applicable regulatory compliance requirements for CO2, methane and nitrous oxide from its owned fossil-fueled EGUs and distribution of natural gas. In addition, Alliant Energy’s environmental stewardship efforts include a goal to partner to plant more than 1 million trees by the end of 2030. Future updates to sustainable energy plans and attaining these goals will depend on future economic developments, evolving energy technologies and emerging trends in Alliant Energy’s service territories.

Other Customer-focused Investments

Electric and Gas Distribution Systems -Customer-focused investments include replacing, modernizing and upgrading infrastructure in the electric and gas distribution systems. Electric system investments will focus on areas such as improving reliability and resiliency with more underground electric distribution and enabling distributed energy solutions with higher capacity lines. Gas system investments will focus on pipeline replacement to ensure safety and pipeline expansion to support reliability and economic development. Estimated capital expenditures for expected and current electric and gas distribution infrastructure projects for 2025 through 2028 are included in the “Electric and gas distribution systems” lines in the construction and acquisition expenditures table in “Liquidity and Capital Resources.”

Grid Resilience and Innovation Partnerships Program for WPL - 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. WPL currently expects to submit project plans to the PSCW in 2025 when award negotiations are nearing completion. If finalized, any grant proceeds would reduce the cost of the project for WPL’s customers.

Fiber Optic Telecommunication Network -Alliant Energy is currently installing fiber optic routes between its 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.

Gas Pipeline Expansion -IPL and WPL currently expect to make investments to extend various gas distribution systems to provide natural gas to unserved or underserved areas in their service territories.

Gas Pipeline Safety - The Pipeline and Hazardous Materials Safety Administration published various final rules from 2019 through 2024 that updated safety requirements for gas transmission pipelines, and updated procedures were implemented to address these rules. Plans to address certain requirements for specific pipelines were developed and implemented, with identified remediation efforts to be completed by July 2035. In response to these rule changes, Alliant Energy, IPL and WPL have been assessing, testing and modifying certain of IPL’s and WPL’s pipelines, and updating practices for assessment and operation of all IPL and WPL pipelines. Alliant Energy, IPL, and WPL also continue to evaluate the impact of these final rules and resulting remediation plans on their financial condition and results of operations.

Technology -Alliant Energy, IPL and WPL currently plan to make investments in technology to enhance productivity and efficiency through automation, customer self-service and telework. Estimated capital expenditures for expected and current technology projects for 2025 through 2028 are included in the “Other” line in the construction and acquisition expenditures table in “Liquidity and Capital Resources.”

Non-utility business -Alliant Energy continues to explore growth of its Travero businesses and other limited scope opportunities outside of, but complementary to, Alliant Energy’s core utility business. This non-utility strategy continues to evolve through exploration of modest strategic opportunities that are accretive to earnings and cash flows.