Constellation Energy has announced a significant acquisition, agreeing to purchase fellow power producer Calpine for nearly $27 billion. This merger combines two of the largest electricity providers in the United States at a time when the demand for power is expected to soar, fueled largely by advancements in artificial intelligence.
The deal is among the most substantial in the U.S. power industry and will serve around 2.5 million customers, as stated in a joint release by both companies on Friday. Constellation plans to acquire Calpine for $16.4 billion, which consists of $4.5 billion in cash and 50 million shares of its own stock. Additionally, Constellation will take on Calpine’s debt of $12.7 billion, leading to a total enterprise value of approximately $26.6 billion. Following the news, Constellation’s stock saw a jump of more than 25%, raising its market cap to around $95 billion.
Joe Dominguez, CEO of Constellation, expressed confidence in the merger, stating that it will allow the company to merge its strong expertise in zero-emission nuclear energy with Calpine’s top-tier low-carbon natural gas and geothermal energy resources. Together, they aim to offer a wider range of energy solutions in the industry.
As power demand hits new highs, largely driven by the rapid expansion of data centers that support various technologies, including AI and e-commerce, consulting firm ICF predicts that the country’s electricity consumption could increase nearly 20% by 2033. This growing demand has benefitted natural gas generation, a reliable energy source that is available 24/7, unlike solar or wind.
Constellation shares have more than doubled over the past year, reflecting positive expectations regarding future energy requirements. Similar trends in stock price increases have been observed among competitors like Vistra and NRG.
Constellation operates the largest fleet of conventional nuclear reactors in the U.S. It previously announced plans to revive the Three Mile Island nuclear plant, historically known for a severe accident, with funding from Microsoft.
Calpine’s operations include 78 gas plants and energy facilities nationwide, generating enough electricity to serve about 27 million homes, primarily in Texas and California. Constellation aims to expand its presence in these key markets.
The acquisition, which is expected to finalize within a year, promises a substantial return for private equity firms like Energy Capital Partners, CPP Investments, and Access Industries, which purchased Calpine for $17 billion in 2017. Analysts project that the move could lead to further consolidation within the power sector, as seen with a recent partnership agreement between private equity group KKR and Canadian pension fund PSP Investments, who targeted a significant stake in American Electric Power’s transmission operations.
Overall, this merger represents a notable shift in the U.S. energy landscape, aligning with the industry’s evolving dynamics and increasing energy requirements.

