TransAlta Corp. is a wholesale power generator and marketer. It focuses on generating electricity in Canada, the United States and Australia through diversified portfolio of facilities fuelled by coal, natural gas, hydroelectric, wind and geothermal resources. The company operates through three business segments: Generation, Energy Trading and Corporate. The Generation segment is responsible for constructing, operating and maintaining electricity generation facilities. The Energy Trading segment is responsible for the wholesale trading of electricity and other energy-related commodities and derivatives and these segments are supported by corporate group. TransAlta was founded in 1909 and is headquartered in Calgary, Canada.