Alliant Energy (LNT) Investor presentation summary

Overview of advance ratemaking process in Iowa

• Utilities can petition the Iowa Utilities Commission to set rate-making principles before building or acquiring new generation facilities or making significant changes to existing ones.

• This process provides utilities with cost recovery certainty and reduces financial risk for future investments.

• The Commission evaluates the availability of alternative electricity sources and the reasonableness of the proposed project compared to alternatives.

• Utilities must demonstrate consideration of alternatives and that their plan is in customers' best interests.

Details of the 2025 advance ratemaking filing

• Filing requests approval for up to 1,000 megawatts of wind generation.

• Regulatory approval is being sought with a decision expected in Q1 2026.

• The filing anticipates 100% eligibility for tax credits.

• Requested return on equity is 11.25%.

• Expected depreciable life of the assets is 40 years.

Forward-looking statements and risks

• Actual results may differ due to uncertainties such as regulatory actions, economic conditions, and ability to obtain approvals.

• Forward-looking statements are based on current information and are not guaranteed.