Constellation Energy (CEG) FY2025 results: revenue $25.5 billion, up 8.3% on the year

Constellation Energy generates electricity and sells electricity, natural gas and other energy-related products to distribution utilities, municipalities, cooperatives and commercial, industrial, public sector and residential customers. It became a separate public company on 1 February 2022, when Exelon distributed all of its shares to Exelon's own holders. It describes itself as the largest nuclear energy company in the United States, and after acquiring Calpine in January 2026 as the largest private-sector power producer in the world. Its five reportable segments are the geographic regions its generation sits in: Mid-Atlantic, Midwest, New York, ERCOT and Other Power Regions.

What it owns

Owned generating capacity was 31,676 MW at the end of 2025, with a further 4,798 MW of contracted generation procured under unit-specific agreements. By region that capacity was 37 percent in the Midwest, 33 percent in the Mid-Atlantic, 15 percent in ERCOT, 10 percent in New York and 5 percent in other power regions. Those owned plants produced 204,944 GWh of electricity in 2025, and the company bought a further 63,999 GWh from spot markets run by the regional grid operators and through bilateral transactions.

Nuclear

The nuclear fleet had generating capacity of approximately 22 GW and produced 183 TWh during 2025, which was 68 percent of the company's total electric supply. It holds ownership interests in 14 nuclear generating stations in service, made up of 25 units, wholly owned except for five jointly held stations: Quad Cities at 75 percent, Peach Bottom at 50 percent, Salem at 42.59 percent, NMP Unit 2 at 82 percent and STP at 44 percent. It operates all of them except Salem and STP, which are run by PSEG Nuclear and STPNOC.

The fleet ran at a capacity factor of 94.7 percent in 2025, and the company reports that its average refuelling outage lasted 22 days that year. In September 2024 it signed a 20-year power purchase agreement with Microsoft to support restarting Three Mile Island Unit 1, retired in 2019 for economic reasons and renamed the Crane Clean Energy Center, which the filing says will have approximately 835 MW of capacity once operational and is subject to regulatory approvals, construction and a renewed operating licence.

Gas, oil and renewables

Approximately 7 GW of natural gas and oil-fuelled plants provide a mix of baseload, intermediate and peak generation, and accounted for 6 percent of electric supply in 2025. Because these plants are generally not licensed, the filing says the decision on when to retire one is fundamentally a commercial one. The renewable portfolio is approximately 2.6 GW of hydroelectric, wind and solar, at 2 percent of supply. The federal energy regulator has the exclusive authority to license most non-federal hydropower projects, which here means the Conowingo project and the Muddy Run pumped storage facility, Muddy Run until December 2055, while Conowingo's new 50-year licence was issued in March 2021 and then vacated in December 2022, with a September 2025 settlement allowing the application to be resubmitted.

Who it sells to

The company serves approximately 2 million customer accounts, including three-fourths of the Fortune 100 companies and approximately 1.4 million residential customers, and states that it is the nation's largest energy supplier for commercial, industrial and residential power volumes based on data from EEI. It served approximately 204 TWh of electric power in 2025 through retail sales and wholesale load auctions. Retail load was approximately 147 TWh of electric power, primarily to commercial and industrial customers, plus approximately 800 Bcf of gas. The wholesale channel, which sells power between utilities and marketers before it reaches an end user, carried approximately 57 TWh across competitive utility load procurement and bilateral sales to municipalities and co-ops. Renewal rates in 2025 were 77 percent for commercial and industrial power customers and 84 percent for the equivalent gas customers.

Alongside plain supply it sells products that match carbon-free generation to a customer's load, including CORe+, which pairs contracted third-party new-build renewable generation with a customer's wish to add carbon-free generation in its own region, and an hourly carbon-free energy platform that matches generation to load every hour and retires the hourly attributes in the applicable registry.

Calpine

Constellation acquired all of Calpine's equity in a cash and stock transaction that closed on 7 January 2026, so the figures above exclude it. After divestitures required for regulatory approval, the filing says Calpine added approximately 23 GW across 72 generation and battery storage assets, 21 GW of it natural gas-fired and mostly combined cycle plants in Texas, California and the Northeast, along with solar and battery storage. It also added approximately 62 TWh of annual load to the retail business and approximately 2,500 employees.

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

Written from the 10-K filed 24 February 2026: read the full 10-K.