Robert J. Durian
Chief Financial Officer at Alliant Energy
Thank you, Lisa. Good morning, everyone. Yesterday, we announced 2024 ongoing earnings of $3.04 per share compared to ongoing earnings of $2.82 per share in 2023. These ongoing earnings contributed to a compounded annual earnings growth rate in excess of 6% over the last 10 years.
Our year-over-year ongoing earnings change was primarily due to higher revenue requirements from capital investments. This positive driver was partially offset by higher depreciation and financing expense and lower AFEDC associated with our customer-focused capital expenditure programs. The remaining year-over-year earnings drivers largely relate to the negative impacts of milder temperatures on electric and gas sales and our team's successful efforts to offset a significant portion of the negative 2024 temperature impacts with actions taken to capture higher tax benefits and lower O&M expenses.
We are extremely proud that our 2024 O&M expenses, excluding non-GAAP adjustments were approximately $30 million less than in 2023. The result of our employees' efforts to manage our business to deliver long-term financial consistency. We also completed restructuring activities in the 4th-quarter of 2024, which resulted in a 5% reduction in our workforce for individuals who chose a voluntary employee separation package, which will provide sustainable cost-savings in the future. The winter temperatures in 2024 were some of the warmest on record in our service territory and across the US.
These temperature impacts on electric and gas margins decreased Energy's earnings by approximately $0.15 per share in 2024. In comparison, temperatures decreased Energy's earnings by $0.06 per share in 2023. Excluding the impacts of mild temperatures, the margins from our electric sales were close to plan with higher-than-expected sales to residential and commercial customers due to greater than forecasted meter growth, partially offset by lower sales to our lower-margin IPL industrial customers, primarily due to less demand from customers who operate their own generation.
In 2024, we continued our steadfast focus on keeping bills cost-effective for the customers we have the privilege to serve. On a revenue per kilowatt-hour basis, average retail electric rates only increased by approximately 2% and 1% for IPL and WPL respectively. Both changes were below the US rate of inflation in 2024. And our average retail natural gas rates on a cost per therm sold declined by approximately 10% when compared to 2023. These results were achieved despite both utilities implementing base rate increases in 2024. We were also successful with many initiatives in 2024 to help create value for our customers in the future. We were awarded $80 million of grants to lower capital costs for customer focus investments.
We secured $3 billion of conditional commitments for loan guarantees from the US Department of Energy's Loan Programs office and if finalized, those loans would help us cost-effectively finance future clean-energy generation and storage for both Iowa and Wisconsin customers. We initiated safe-harbor activities with the intention of preserving the qualification of tax credits for future energy storage and renewable projects.
And as Lisa mentioned, we are utilizing our individual customer rate construct in both states, which allows us to capture growth from economic development activities occurring within our states, which will in-turn absorb a portion of our fixed costs helping reduce cost for all customers. Our teams also had success with improving cash flows last year. 2024 cash flows from operations increased by approximately $300 million or 35% when compared to 2023. This substantial increase was primarily the result of the successful monetization of tax credits generated in 2024, improved recoveries of infrastructure investments with new base rates in both Iowa and Wisconsin, and successful efforts by our employees to reduce the working capital requirements of our core utility business.
I'm also pleased to report that our investing cash flows in 2024 aligned with our projected capital expenditures set at the beginning of the year due to our proactive procurement activities and our continued track-record of successful execution of our key construction projects. Moving to 2025, we are affirming our 2025 earnings guidance range of $3.15 to $3.25 per share, share and we have based our long-term 5% to 7% earnings growth rate target off our 2024 ongoing earnings of $3.04. Our efforts to support customer value by making smart investments and controlling operating costs, all while receiving constructive regulatory outcomes will support our ability to consistently deliver solid financial results.
Turning to 2025 financings, our current 2025 financing plans are included on Slide 8. We anticipate updating our 2025 to 2028 financing plans in conjunction with our next capital expenditure update, which we expect to share on next quarter's earnings call. Finally, I'll highlight our regulatory initiatives in-progress as well as those regulatory filings we plan to initiate later this year. We have four active dockets in-progress before the Public Service Commission of Wisconsin, which involve requests for certificates of authority for customer-focused investments.
These dockets relate to investments, which will enhance the reliability and resiliency of the Riverside natural gas generating facility. We refurbished the Ford Wind and Bentry wind farms to extend production tax credits from the facilities for the benefit of our customers and enable a new long-duration energy storage project called Energy Dome, which will be cited next to WPL's Columbia Energy Center. The expected timing of decisions from the Public Service Commission of Wisconsin of these dockets is provided on Slide nine. We also have two active filings in-progress before the Iowa Utilities Commission seeking approval for an individual customer rate for one of the new data centers in Cedar Rapids, Iowa and an approximate 100 megawatt Cedar River natural gas generating station, which would be located on the existing side of the Prairie Creek generating station.
Finally, for our planned regulatory filings this year, we anticipate filing a Wisconsin retail electric and gas rate review for test years 2026 and 2027 at the end of this quarter. And in conjunction with our updated capital expenditure plan, we also expect to make regulatory filings later this year in both Iowa and Wisconsin for additional renewables and dispatchable resources to enhance reliability, further diversify our energy resources and meet growing customer energy needs. We thank you for your continued support and look-forward to speaking with many of you in the coming months.
At this time, I'll turn the call-back over to Lisa to provide closing remarks.
