Calpine Calif. Pastoria natgas unit back

NEW YORK, June 2 (Reuters) - Calpine Corp's (CPN.N) 724-megawatt Pastoria natural gas-fired power station in California returned to full service by Monday afternoon, the California Independent System Operator said in a report.

The unit was curtailed by 515 MW Sunday afternoon. It had been de-rated for planned and unplanned reasons since about May 25.

The 724 MW Pastoria combined cycle station is located in Lebec in Kern County about 30 miles south of Bakersfield, California, on property leased from Tejon Ranch Corp.

There are three 156 MW combustion turbines at the station and two heat recovery steam turbines rated at 169 MW and 87 MW.

Calpine also plans to add a 160 MW simple-cycle, gas-fired combustion turbine at Pastoria at a cost of between $100 million and $200 million. If built the new unit could enter service in 2011.

One MW powers about 700 homes in California.

Calpine, of San Jose, California, owns and operates nearly 24,000 MW of generating capacity in operation and under construction and markets energy commodities in North America. (Reporting by Scott DiSavino; Editing by John Picinich)