GREEN CITY The push from city leaders to shut down Mirant's aging Potrero power plant advanced another step June 2 when the San Francisco supervisors approved an ordinance sponsored by Sophie Maxwell and Michela Alioto-Pier that urges closing the entire facility by the end of 2010 and directs the San Francisco Public Utilities Commission to update a plan charting the city's energy future.
But the current city proposal for closing the Mirant plant appears to rely entirely on replacing that power with the output of other private fossil fuel plants in someone else's backyard.
The city is following the same script as Pacific Gas and Electric Co., which wants to upgrade and expand the lines bringing its own private power into the city instead of San Francisco generating power of its own.
In fact, Mayor Gavin Newsom has introduced legislation to sell four city-owned combustion turbines that are currently collecting dust in storage in Houston. Obtained as part of a 2003 lawsuit settlement, the turbines were almost employed last year to build four small city-owned power plants to fully replace the Mirant facility but that plan was ultimately shot down.
The California Independent System Operator (Cal-ISO), a federally regulated body that oversees grid reliability, currently requires Mirant's dirty San Francisco facility to stay in service to provide in-city generation capacity in case of catastrophic power grid failure. But city officials now say a new underwater power cable from the East Bay could replace Mirant Unit 3, which spews fumes into the Bayview-Hunters Point neighborhood.
Last month, Newsom, Board of Supervisors President David Chiu, City Attorney Dennis Herrera, SF Public Utilities Commission General Manager Ed Harrington and Sups. Sophie Maxwell and Michela Alioto-Pier sent a letter to Cal-ISO making the case that with the installation of the TransBay Cable which would link the city with generating facilities in Pittsburg and other planned system upgrades, the entire Mirant facility could be retired by next year.
Maxwell's ordinance references that letter, and urges PG&E to "develop expeditiously" its transmission-upgrade projects to pave the way for the plant's closure. Cal-ISO spokesman Gregg Fishman says that so far, it hasn't reviewed PG&E's plans.
Joe Boss, a longtime member of the city's power plant task force, says he has little confidence that Mirant can be shut down without being replaced with new in-city electricity generation. He told us he believes it's a bad move to sell off the publicly owned combustion turbines.
The TransBay Cable is essentially a 10-inch thick extension cord that would connect a PG&E substation in Pittsburg with another PG&E substation in Potrero Hill. It's being bankrolled by the Australian investment firm Babcock & Brown, which ran into serious financial trouble during the economic downturn, and its San Francisco branch was bought out last month. Currently under construction, the cable project is being built in tandem with the Pittsburg power company, a municipal utility that would retain ownership of the cable and converter stations. PG&E customers will ultimately pay for power transmitted over the line.
The way the theory goes, once the cable goes live next March, Potrero's Unit 3 a natural-gas fired generator that runs about 20 hours a day could finally be shut down.