TransAlta Corporation is a power generating company. The Company owns, operates and manages a portfolio of assets representing approximately 8,128 megawatts (MW) of capacity and uses a range of fuels comprised of water, wind and solar, natural gas, and thermal coal. Its segments include Generation Segments and Energy Marketing Segment. Generation Segments include six segments: Hydro, Wind and Solar, North American Gas, Australian Gas, Alberta Thermal, and Centralia. Its Energy Marketing segment is engaged in the wholesale trading of electricity and other energy-related commodities and derivatives. Energy Marketing manages available generating capacity as well as the fuel and transmission needs of the generation segments by utilizing contracts of various durations for the forward sales of electricity and for the purchase of natural gas and transmission capacity.