Press Release

Mayor Newsom And California Independent System Operator Announce Effective End To Potrero Power Plant Operations By December 31

California ISO to Remove Plant’s “Must Run” Obligation Beginning January 1, 2011 and Does Not Plan to Require Plant Operation After December 31, 2010

12/21/10 - Mayor Gavin Newsom and the California Independent System Operator (California ISO), the nonprofit state organization that oversees the reliability of California’s electric grid, today announced that the GenOn Energy/Mirant-owned Potrero Power Plant in San Francisco will effectively cease operations by December 31. With the Trans Bay Cable successfully placed into commercial operation and the final segment of the San Francisco Recabling Project (Martin-Bayshore-Potrero) completed by PG&E, California ISO will release the Potrero Power Plant from its reliability must-run (RMR) contract obligation, allowing the plant to close entirely.

“Today is a historic day for so many who have worked for years to close this power plant,” said Mayor Newsom. “This is a monumental step towards cleaner air, environmental justice and our future of renewable energy and healthier communities. I want to express my sincere thanks to California ISO President & CEO Yakout Mansour for working closely with San Francisco to find a way to shutter the City’s last fossil fuel power plant while protecting the reliability of our electric grid. It has been a long and sometimes difficult road, but at last, we come together to celebrate this victory for the people of the Southeast sector and our entire City.”

“The California ISO’s job was to keep the lights on while the local infrastructure was developed to support removal of the Potrero Power Plant from the power grid,” said Yakout Mansour, California ISO President & CEO. “We thank Mayor Newsom for striking the right balance between the wishes of the community and the security of the electric supply to San Francisco.”

In a letter today, California ISO provided the RMR termination notice to GenOn Energy/Mirant effective January 1, 2011, which would technically terminate the RMR agreement by February 28, 2011. However, the California ISO will not plan to dispatch the Potrero power plant at all during this two month termination period, except in an extreme emergency, effectively ceasing operations after December 31, 2010.

“We are happy to be partners with the City and County of San Francisco,” said John Chillemi, President of GenOn West, formerly Mirant. “It has been a bit of a roller coaster to get here, but today we’re celebrating what was anticipated in our agreement with the City.”

“It’s a win-win for the residents of Potrero and Dogpatch neighborhoods and our entire City,” said Supervisor Sophie Maxwell. “The closure of the last fossil fuel plant in San Francisco furthers our clean energy goals and ensures a healthier environment for our City’s future.”