Update on effort to close Potrero power plant


By Rebecca Bowe

The California Independent System Operator (ISO), a quasi-governmental body that oversees the state’s electric grid, held a hearing about San Francisco’s Mirant Potrero Power Plant on Friday to decide whether the polluting facility should be required to stay in operation through next year.

The hearing came about a month after City Attorney Dennis Herrera struck a deal with Mirant to shutter the entire plant by the end of 2010. That agreement will only stick if the ISO is willing to release the plant from a Reliability Must Run (RMR) contract, which has kept it in operation for decades despite opposition from San Francisco elected officials.

In short, the ISO indicated that it would be willing to release Unit 3 -- which represents the lion’s share of the power plant’s emissions -- from the RMR contract by spring of 2010, but it still hasn’t budged on the smaller, diesel-fired units known as 4, 5, and 6.

We received this detailed update from Joshua Arce, executive director of the Brightline Defense Project, who attended the hearing.

I would summarize by saying that environmental and community groups saw movement from ISO, but we think they can do better.

The best news out of the hearing is that ISO staff confirmed they are drafting contractual language that will end the must-run contract on the Potrero Unit 3 smokestack (representing about 60% of the whole facility, most of the plant's emissions, and all of the superheated bay water discharge) upon spring 2010 completion of the Trans Bay Cable, but staff was non-committal on the timeline for removing must-run designation on Units 4, 5, and 6.

There were 10 of us from the community and environmental organizations (Brightline, Green Party, Greenaction, SF Community Power, Huntersview Mothers Committee) present, and 6 speakers unanimously called for the ISO to adopt the position articulated in the City's May 8, 2009 letter to ISO's Yakout Mansour: "let us shut Unit 3 on January 1, 2010." We added a second request, which was "remove must-run designation from the remaining Potrero Units upon completion of Trans Bay Cable, effectively allowing us to shut the entire Potrero facility in the 1st quarter 2010."

Two of four ISO Governors asked Transmission Director Gary DeShazo whether shutting Unit 3 at the end of this year was feasible, and he responded "not until Trans Bay Cable comes online." With respect to the remaining Units, Mr. DeShazo did not waver in stating that in his view, even after one of the city's power lines is done being re-cabled in October 2010, there is still a 25 megawatt gap.

The ISO Board voted to accept ISO staff's recommendation to renew the "must-run" contract for Potrero, with the condition described for Unit 3. However, the Board told the public that new information had recently been received from the City and that this issue would be evolving...ISO will make a final decision in late October...

The battle to shut down the plant will continue on a different front this coming Wednesday, when the State Water Resources Control Board holds a public hearing on setting new standards for the ecologically harmful cooling system used at the Mirant facility. City representatives will be there to push for denial of the water permit for Mirant’s Unit 3 boiler, according to activist Eric Brooks. Details about the hearing can be found here.