Calpine is a Fortune 500 company based in Houston, Texas. It is the largest generator of electricity from natural gas and geothermal energy in the United States, with operations in competitive power markets.

Through wholesale power operations and its retail businesses, Calpine serves customers in 24 states, Canada, and Mexico.

Its fleet of 80 power plants in operation or under construction has nearly 26,035 megawatts of generation capacity.

In 2019, it reported generating 100.8 million megawatt hours of electricity.

Calpine is the largest generator of electricity from natural gas and geothermal resources in the United States.

In addition to its retail business, Calpine is a merchant power plant operator that sells power to utilities at market rates.

Champion Energy is a subsidiary of Calpine. It is a retail electricity provider based in Houston, Texas. Champion Energy currently serves residential, governmental, commercial and industrial customers in deregulated electric energy markets in Texas, Illinois, Ohio, Pennsylvania, New Jersey and New York; governmental, commercial and industrial customers in Delaware, Maryland and Washington, D.C.; and natural gas customers in Illinois.

York Energy Center is a 565-megawatt natural gas-fired power plant located in Peach Bottom Township, York County, Pennsylvania.