Constellation Energy

Constellation Energy’s generation business traces back to Exelon. In October 2000, Unicom and PECO merged to create Exelon Corp. In December 2003, Exelon Generation acquired British Energy’s 50% stake in the nuclear joint venture AmerGen, and in January 2009 it folded AmerGen’s nuclear assets into Exelon Nuclear and dissolved AmerGen.⁠[1]

On March 12, 2012, Exelon and Constellation Energy Group completed their merger, creating what the companies called the nation’s No. 1 competitive energy provider, with approximately 35,000 megawatts of owned generation. Christopher M. Crane became president and CEO of the combined company and Mayo A. Shattuck III executive chairman. The Constellation business unit supplied energy products and services to business, public sector and residential customers.⁠[2]

On February 21, 2021, Exelon’s board “authorized management to pursue a plan to separate its competitive generation and customer-facing energy businesses” into an independent, publicly traded company. Constellation Energy Corporation, a Pennsylvania corporation, was newly formed as a wholly owned Exelon subsidiary for the separation. Its operating subsidiary Constellation Energy Generation, LLC was formerly Exelon Generation Company, LLC.⁠[3]

On January 26, 2022, S&P Dow Jones IndicesS&P Dow Jones IndicesS&P Dow Jones Indices (S&P DJI) is a global index provider that compiles and licenses benchmark indices including the S&P 500 and the Dow Jones Industrial Average. It was formed in 2012 by combining McGraw-Hill’s S&P index business with the Dow Jones Indexes business held by a joint venture of CME Group and Dow Jones, and it is now the index business division of S&P Global, which holds about 73% of the interest.Open the full entry announced that Constellation Energy would join the S&P 500S&P 500The S&P 500 is a U.S. large-cap equity index compiled by S&P Dow Jones Indices. It includes 500 leading companies, covers about 80% of available market capitalization and is described by S&P DJI as “widely regarded as the best single gauge of large-cap U.S. equities.”Open the full entry, replacing The Gap, once Exelon completed the spin-off, with the company classified in the Utilities sector. The announcement’s table lists the addition as effective February 2, 2022.⁠[4]

With a record date of January 20, 2022, Exelon completed the distribution at 12:01 a.m. Eastern Time on February 1, 2022, giving shareholders one share of Constellation common stock for every three Exelon shares and retaining no ownership interest. Joseph Dominguez became president and chief executive officer, and Robert Lawless chair of the board.⁠[5]

On February 2, 2022, Constellation stock began regular-way trading on the Nasdaq Global Select Market under the symbol CEG. The company then described itself as “the nation’s largest producer of carbon-free energy,” with more than 32,400 megawatts of capacity serving about 2 million residential, public sector and business customers, and set a goal of 100 percent carbon-free electricity by 2040.⁠[6]

After the U.S. Nuclear Regulatory Commission announced its approval on October 31, 2023, Constellation completed its USD 1.75 billion acquisition of NRG Energy’s 44% stake in the two-unit South Texas Project nuclear plant.⁠[7]

On September 20, 2024, Constellation announced a 20-year power purchase agreement with MicrosoftMicrosoftMicrosoft is a technology company founded by Bill Gates and Paul Allen in 1975 and headquartered in Redmond, Washington, with businesses spanning Windows, Microsoft 365, Azure, enterprise software, artificial intelligence, gaming and devices.Open the full entry that would pave the way for the restart of Three Mile Island Unit 1, which was retired in 2019 due to economic conditions. The unit was to be renamed the Crane Clean Energy Center and was expected to be ready for service in 2028.⁠[8]

On January 10, 2025, Constellation announced the purchase of Calpine, a Houston-based natural gas and geothermal power provider, for 50 million Constellation shares and USD 4.5 billion in cash plus the assumption of about USD 12.7 billion of Calpine debt, a deal valued at USD 26.6 billion including debt. It required several regulatory approvals.⁠[9]

On June 3, 2025, Constellation and Meta signed a 20-year agreement under which MetaMetaMeta (Meta Platforms, Inc.) is a publicly listed American technology company, renamed from Facebook in 2021, that operates social communication, digital advertising, virtual reality, smart glasses and artificial intelligence businesses.Open the full entry would buy 1,121 megawatts of nuclear energy from the Clinton Clean Energy Center in Illinois from June 2027, with uprates adding 30 megawatts. Dominguez said, “Sometimes the most important part of our journey forward is to stop taking steps backwards.”⁠[10]

In November 2025, the U.S. Department of Energy issued a guarantee for up to USD 1 billion of an unsecured loan supporting the financing of the Crane Clean Energy Center restart.⁠[11]

On December 5, 2025, the U.S. Justice Department and the Texas attorney general required Constellation to divest six power plants, four in PJM and two in ERCOT including the Jack A. Fusco Energy Center, to proceed with the Calpine acquisition. The department filed a civil antitrust lawsuit together with a proposed settlement subject to court approval.⁠[12]

As of December 31, 2025, Constellation had 15,339 employees. Its nuclear fleet, the nation’s largest, had about 22 GW of capacity and produced 183 TWh in 2025.⁠[13]

Constellation’s fiscal 2025 operating revenues were USD 25.533 billion (2024: USD 23.568 billion), and GAAP net income attributable to common shareholders was USD 2.319 billion, or USD 7.40 per diluted share.⁠[11]

On January 7, 2026, Constellation completed its acquisition of Calpine, giving the combined company 55 gigawatts of capacity. Dominguez said, “This isn’t just about two great companies coming together — it’s about strengthening America’s future.”⁠[14]

The combined company became the nation’s largest producer of electricity, adding Calpine’s natural gas-fired and geothermal generation to its nuclear business.⁠[15]

On June 9, 2026, the U.S. Nuclear Regulatory Commission found that restarting the Crane Clean Energy Center in Middletown, Pennsylvania, would have no significant environmental impact, and released a draft environmental assessment for comment until July 8. The agency continued its safety reviews and on-site inspections, with a final restart decision expected in 2027.⁠[16]

In the second quarter of 2026, Constellation had operating revenues of USD 7.504 billion and GAAP net income attributable to common shareholders of USD 513 million. It agreed to sell the 606 MW Brazos Valley Energy Center, formerly Jack A. Fusco, to LS Power for USD 860 million before closing adjustments, the last asset sale required under its Calpine acquisition commitments, subject to Justice Department approval.⁠[17]