TransAlta Corporation (TSX: TA NYSE: TAC) (formerly:Calgary Power) is a Canaian energy company based in Calgary, Alberta. It operates 51 power plants in Canada, the United States, Mexico, and Australia. These plants have a total net ownership electricity generation capacity of 8,473 MW (as of December 2005). TransAlta owns 50% of CE Generation, and in 2002 purchased Vision Quest Windelectric Inc..