Ameren (AEE) FY2025 results: revenue $8.8 billion, up 15.4% on the year

Ameren is a public utility holding company formed in 1997 and headquartered in St. Louis, Missouri, whose primary assets are the equity interests in its subsidiaries. Ameren Missouri operates a rate-regulated electric generation, transmission and distribution business and a rate-regulated natural gas distribution business in Missouri. Ameren Illinois operates rate-regulated electric transmission, electric distribution and natural gas distribution businesses in Illinois. ATXI operates a transmission business regulated by the federal energy regulator within MISO. The four reportable segments follow those lines: Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Transmission. Ameren had 8,913 employees at the end of 2025 with an average tenure of 13 years, of whom 3,767 were at Ameren Missouri, 3,168 at Ameren Illinois and 1,978 at Ameren Services.

What it sells

Electricity sales were 69,416 million kilowatthours in 2025. Ameren Missouri's retail load was 31,796 million, made up of 13,972 million commercial, 13,675 million residential, 4,087 million industrial and 62 million to street lighting and public authorities, with off-system sales of 3,466 million on top. Ameren Illinois Electric Distribution carried 34,154 million, split 11,755 million commercial, 11,516 million residential, 10,485 million industrial and 398 million street lighting and public authority.

Natural gas sales were 192 million dekatherms. Ameren Illinois accounted for 171 million of that, with transport at 100 million and residential at 52 million; Ameren Missouri's 21 million was 9 million transport and 7 million residential.

Two different businesses under one roof

Ameren Missouri's electric supply is primarily generated from its own energy centres, and it buys power only for reasons such as an outage, meeting renewable requirements, extreme weather, or power being available below its own generation cost. In Illinois, transmission and distribution service rates are regulated but power supply prices are not, customers may buy power from an alternative retail electric supplier, and Ameren Illinois is required to be the provider of last resort. In 2025 it procured power on behalf of customers for 28 percent of its total kilowatthour sales, through processes run by the Illinois state power agency or through MISO markets, and passes the purchased power and procurement costs directly to those customers.

Rates are set by the Missouri utility regulator, the Illinois utility regulator and the federal energy regulator. The filing says decisions by those bodies are largely outside the company's control, and are influenced by the cost of providing service, the prudency of expenditures, the quality of service, regulatory staff knowledge and experience, customer intervention, economic conditions, and social and political views.

Generation

Ameren Missouri owns energy centres that rely on a diverse fuel portfolio including coal, nuclear and natural gas along with renewables. Both coal-fired energy centres were constructed before 1978. The Callaway nuclear energy centre began operation in 1984 and is licensed to operate until 2044. Ameren Missouri burned approximately 12.0 million tons of coal in 2025, approximately 96 percent of it bought from the Powder River Basin in Wyoming, which the filing notes has a limited number of suppliers, and the rest typically from the Illinois Basin. The filing says deliveries from the Powder River Basin have occasionally been restricted by rail congestion, staffing and equipment issues, infrastructure maintenance, derailments, weather and supplier financial hardship.

Ameren Illinois operates two solar generation facilities, two of the three pilot solar projects it is allowed to invest in under state law, with the third planned to be in service before the end of 2026.

What it plans to build

Ameren Missouri files a long-term non-binding preferred resource plan with the Missouri regulator every three years, and in February 2025 filed a change to its September 2023 plan to address load growth from data centre and manufacturing companies considering locating or expanding in its territory. That change estimates total load growth of 1.5 gigawatts by 2032 and 2.5 gigawatts by 2040, and sets out adding 1,600 MW of natural gas-fired simple-cycle generation by 2030 and a further 1,200 MW by 2043, 2,100 MW of natural gas-fired combined-cycle generation by 2035 and a further 1,200 MW by 2040, 3,200 MW of renewable generation by 2030 and a further 1,500 MW by 2035, and 1,000 MW of battery storage by 2030.

The transmission system

Ameren owns an integrated transmission system made up of the assets of all three utilities, and operates two MISO balancing authority areas. The Missouri area, which includes Ameren Missouri's load and most of its energy centres, had a peak demand of 7,487 MW in 2025; the Illinois area, which includes Ameren Illinois' load and certain Ameren Missouri energy centres located in Illinois, had a peak demand of 8,027 MW. The system connects directly with 15 other balancing authority areas for the exchange of electric energy.

Renewable requirements

Missouri utilities must purchase or generate electricity equal to at least 15 percent of native load sales from renewable sources, at least 2 percent of it from solar, subject to an average 1 percent annual limit on increases to customer rates over any 10-year period, and generation from facilities inside Missouri counts at 125 percent. In Illinois, Ameren Illinois must collect $4.58 per MWh from all electric distribution customers to fund state procurement of renewable energy credits, an amount that gains an annual inflation adjustment from June 2026.

From Ameren's annual report on Form 10-K for the year ended 31 December 2025. The filing

Written from the 10-K filed 18 February 2026: read the full 10-K.