Calpine Corp. and a Bechtel Group unit have formed a joint venture to invest around $1bn in the development of power plants in northern California. The deal involves three or four plants in the San Francisco bay area. Calpine has also announced a joint venture with Sonat Energy Services to develop a 680 MW natural gas fired peaking power plant in Georgia. Separately, Calpine has awarded Westinghouse the contract for a 700 MW power plant plus long-term maintenance agreement.