Constellation Energy (Nasdaq: CEG) completed its acquisition of Calpine on Jan. 7, creating the nation’s largest electricity producer with approximately 60 gigawatts of combined generating capacity.
The cash-and-stock transaction, first announced in January 2025, valued Calpine at roughly $16.4 billion in equity—comprising 50 million Constellation shares and $4.5 billion in cash—plus the assumption of $12.7 billion in net debt, bringing the total net purchase price to $26.6 billion. It ranks among the largest power-sector deals in U.S. history.
The deal unites Constellation’s nuclear fleet, the country’s largest, with Calpine’s 26 gigawatts of natural gas capacity and its Geysers geothermal complex in California, the world’s biggest. The combined company now serves roughly 2.5 million customers across 22 states.
Management expects the acquisition to boost adjusted earnings per share by more than 20 percent in 2026 and add over $2 billion in annual free cash flow. Constellation has already moved to capitalize on the expanded portfolio, signing a 380-megawatt data-center power agreement with CyrusOne in Texas shortly after closing.
Constellation will remain headquartered in Baltimore, maintaining a significant presence in Houston. Calpine CEO Andrew Novotny will continue leading the Calpine business unit. Calpine’s former owners, led by Energy Capital Partners, have agreed to an 18-month lock-up on shares received as deal consideration.