Constellation Energy Corporation operates as the largest pure-play producer of carbon-free electricity in the United States13. Spun off from Exelon Corporation in 2022, the company commands approximately 55 gigawatts (GW) of generation capacity, encompassing nuclear, natural gas, geothermal, hydroelectric, wind, and solar facilities2. The company operates a vast competitive retail supplier network, serving roughly 2.5 million customer accounts, including a significant majority of the Fortune 100

The structural integration of Calpine Corporation in early 2026 transformed Constellation's asset base. The $21.835 billion acquisition added approximately 23 GW of primarily natural gas and geothermal generation capacity, bridging the gap between Constellation's rigid baseload nuclear operations and the flexible, dispatchable power required to stab ...