San Francisco will have to rely on its aging Hunters Point and Potrero power plants for at least two and a half more years because four new efficient peaking turbines will not come on line until summer 2007, city officials projected. ?It?s taken us a lot longer to get these units permitted and built because we?ve been trying to solve a reliability problem and local power need rather than just planting them somewhere,? said Ralph Hollenbacher, an official with the San Francisco Public Utilities Commission. The four 50 MW gas-fired turbines remain in a Houston warehouse while San Francisco officials negotiate their way through state and local permitting processes to bring the new generators on line, he said. San Francisco will receive the turbines free of charge from Williams Energy Marketing & Trading as part of a $417 million settlement reached with the California attorney general in late 2002 following two lawsuits claiming the generator gouged the state during the energy crisis. However, San Francisco PUC officials estimate that the city will have to issue $150 million in bonds to construct the infrastructure to house three of the turbines, which will be located on city-owned land near the Potrero plant and the San Francisco shipyards. The fourth turbine will be located at San Francisco International Airport, which currently receives electricity from the dam at Hetch Hetchy. The 43-year-old Hunters Point and 38-year-old Potrero power plants could be shut down after the four turbines come on line, if the California Independent System Operator approves. Local residents charge that toxic emissions from the plants are a public health menace, causing cancers and respiratory illnesses. While Pacific Gas & Electric divested its other gas-fired power plants in 1997, it retained ownership of Hunters Point with the caveat that the polluting plant would be closed once San Francisco had adequate generation to ensure system reliability. The Potrero plant, now owned by Mirant Energy, is undergoing retrofits for emissions reductions and is scheduled to come back on line within a few months, Hollenbacher said. The retrofit recommenced several weeks ago, after Communities for a Better Environment, which had sued to stop the retrofit project, dropped its suit. Transmission construction projects by PG&E, the turbines, and closure of the Hunters Point and Potrero power plants and two 52 MW diesel fuel oil?fired backup generators are part of a revised San Francisco Action Plan approved by the California Independent System Operator last November. The upgrades will enable CAISO to remove its reliability-must-run contracts for the Hunters Point and Potrero plants, Hollenbacher said. While the turbines will be owned by the city, their output for the first 10 years will be contracted with the California Department of Water Resources and dispatched by PG&E. A permit application for the three turbines is under review at the California Energy Commission. Assuming the certification is granted, the San Francisco Board of Supervisors will have to approve it and issue the construction and financing bonds.