Residents and advocates urge SFPUC to pause proposed Potrero combustion turbines as questions persist about Mirant closure and Cal ISO role

At a public workshop on the San Francisco electric reliability project, dozens of Bayview-Hunters Point and Potrero Hill residents and environmental advocates told the San Francisco Public Utilities Commission they oppose siting three new combustion turbines (CTs) near their neighborhoods and urged the commission to postpone final approval until the existing Mirant Potrero power plant is guaranteed to close.

Why it matters: Community speakers and advocacy groups argued the city should not add new fossil-fuel peaker units near homes, daycare centers and schools while uncertainty remains about whether the Mirant plant would be retired. They pressed commissioners to seek clear commitments from the plant owner and from the California Independent System Operator (Cal ISO) about the reliability and operational consequences of the newer transmission infrastructure known as the Transbay cable.

In remarks during public comment, Espinosa Jackson of Bayview-Hunters Point said she had been told by Cal ISO that if the Transbay cable is installed, the CTs would not be needed. "I was told by ISO, no," Jackson said, adding she was upset to receive a staff letter dated Sept. 25 that she read as implying the commission supported the CTs.

Advocates raised legal and public-health challenges. Joshua Arce, staff attorney with a civil-rights nonprofit, told the commission his organization filed a federal lawsuit on Sept. 24 and has asked the California Energy Commission to reconsider its certification of the project. Arce said his white paper – submitted to the commission – cites a September 2007 San Francisco Department of Public Health finding urging that final approval of CT siting should not proceed unless closure of the older plant is ensured.

Commissioners and staff acknowledged unresolved questions. Several commissioners said there has been internal disagreement at Cal ISO about the need for the CTs. Commissioners asked staff to provide as much of the negotiated J Power contract terms and supporting materials as possible for review before any vote; staff said it was finalizing terms and would return them several days prior to any decision. The deputy general manager also noted that the decision to close Mirant's plant is ultimately Mirant's and may be influenced by Cal ISO, FERC and the California Public Utilities Commission.

The commission agreed to invite Cal ISO to present at a future meeting so commissioners and the public can hear the operator's reliability analysis directly. President Brooks said the choices before the commission "aren't good ones," and asked that the next meeting include a presentation from Cal ISO and additional staff materials.

What was not decided: No formal vote on siting or certifying the combustion turbines occurred at the workshop. Staff and commissioners discussed scheduling a special or upcoming meeting to review the term sheet and related environmental documents before any action.

Next steps: Staff committed to provide the negotiated terms and related documents in advance of the next meeting; commissioners requested Cal ISO attend to explain RMR (reliability-must-run) designation implications and the Transbay cable's reliability contribution. Community groups asked for any draft terms to be made available for public review and comment.

Attribution: "The final approval of citing the new CTs should not be permitted unless the plant closure is guaranteed," Joshua Arce said in public comment. "I was told by ISO, no," Espinosa Jackson said of whether CTs would be needed if the Transbay cable is built.

Ending: The commission closed public comment and scheduled further review; no action was taken on resolution 70,137 at this meeting.