The long-awaited closure of one of California’s dirtiest power plants, located in southeastern San Francisco, could be soon at hand, according to a letter today from state energy regulators.

The letter from Yakout Mansour, president and CEO of the California Independent System Operator, to Mayor Gavin Newsom said the agency had recently received new information that would no longer require the Mirant power plant in the Potrero District to continue to operate.

Cal-ISO is tasked with maintaining the reliability of the state’s electrical grid. The agency has previously said that until other sources of power come on line, the Potrero plant had to continue to operate.

“After years of work, we have finally obtained the long-sought commitment from state energy regulators that will allow us to close the old, polluting Potrero power plant this year,” Newsom said.

He called it “a major step for environmental justice for the southeast and Potrero Hill communities.”

The aging plant is blamed for heavy pollution in one of the most economically disadvantaged parts of the city. Residents have complained about higher rates of asthma and other health problems.

In 2006, the city successfully shuttered a similar plant in the neighboring Hunters Point.

Mansour said Cal-ISO had new information about the capacity of underground transmission cables from the Peninsula to the city that are being upgraded by PG&E, which would allow three of the plant’s generators to be closed.

“Our conclusion regarding the closure of these three units is in addition to the ISO’s earlier determination that Potrero Unit 3, the largest of the four operating Potrero generators, can retire once the Trans Bay Cable project demonstrates its reliability,” Mansour wrote.

The Trans Bay Cable is expected to deliver 400 megawatts of power to the city via a cable from Pittsburg that stretches under the San Francisco Bay.

Newsom spokesman Tony Winnicker said today that the cable is expected to be completed as soon as next month and will then be subject to a few months of testing.

With Mirant Corp.’s commitment to shut down the plant once given approval by Cal-ISO, “We’re hoping for (closure in) the fall,” Winnicker said. “As soon as possible, obviously.”
Winnicker said both Mirant and PG&E, the plant’s former owner, are responsible for cleanup of the plant site, and that the mayor’s office has been discussing plans for redevelopment of the site.

“This has been a long time coming,” said Supervisor Sophie Maxwell, whose district includes the Potrero and Bayview communities and who has been on the front lines of crusading for the closure of both power plants.

Maxwell organized community groups to work with parties on all sides in examining the best ways to close the plants without jeopardizing the city’s power supply.

“I just really applaud the community,” she said. “This is a victory for all of those folks.”
Joshua Arce, executive director of the Brightline Defense Project, a civil rights and environmental advocacy group that has also been calling for the Potrero plant’s closure, struck a more cautionary tone today.

“It’s definitely a step forward, but it doesn’t mean that the community doesn’t have to organize,” Arce said. He called on concerned groups to attend Cal-ISO’s next meeting in February “and make the case that the whole power plant must shut down after they know the Trans Bay Cable is working.”

Please make sure your comment adheres to our comment policy. If it doesn't, it may be deleted. Repeat violations may cause us to revoke your commenting privileges. No one wants that!