Constellation Energy Corporation is a major U.S. energy company and the nation's largest producer of electricity following its 2026 acquisition of Calpine. The company operates a large nuclear generation fleet alongside natural gas and geothermal assets and is increasingly focused on meeting rising electricity demand from data centers and AI infrastructure. Constellation has signed major agreements with technology and data center companies, including Microsoft and CyrusOne. Its Crane Clean Energy Center project in Pennsylvania is expected to restore 835 MW of carbon free generation for the grid under a 20 year agreement with Microsoft. In Texas, Constellation and CyrusOne are developing data center infrastructure adjacent to the Freestone Energy Center, with 380 MW initially contracted and another 380 MW planned.