Constellation Energy Corporation

Constellation Energy Corporation is the largest producer of carbon-free electricity in the United States, operating 21 nuclear reactors across 13 sites alongside a growing portfolio of natural gas, geothermal, hydro, wind, and solar assets following its acquisition of Calpine Corporation in January 2026, with combined generating capacity of approximately 55 gigawatts. The company also runs the nation's largest competitive retail energy platform, serving roughly 275 million megawatt-hours of electricity and 800 billion cubic feet of natural gas annually to customers across 40 states, including more than three-quarters of the Fortune 100.

This is a story about what happens when the country's largest fleet of firm, around-the-clock clean power collides with the most consequential demand shock the electric grid has seen in a generation. Constellation's nuclear plants, long valued as steady but unremarkable baseload utility assets, are being re-priced by the market as an irreplaceable resource at the center of the AI infrastructure buildout. The Calpine acquisition added natural gas and geothermal assets that fill the intermittency gap solar and wind cannot, and a retail book that gives Constellation a direct line to the commercial and industrial customers driving load growth. The file turns on a single question: whether the premium the market now assigns to clean, firm megawatt-hours is structural and durable, or whether it reflects a moment of AI enthusiasm that the supply response and regulatory process will eventually erode.