Dianne Feinstein's husband, Richard Blum, has a long history with the city. The tidal power study was not subject to competitive bids and was awarded to URS because the company had undertaken significant computer models of the entire Bay Area for a past proposal to fill in part of the waterway to extend runways at San Francisco International Airport, Blumenfeld said. That plan was shot down, but the environmental impact report it spawned contains information relevant to studying tidal power.
Additionally, URS has an as-needed work agreement with San Francisco, Blumenfeld said, "and everything moves glacially" in regard to contracting with the city.
The kind of tidal power being considered called "in-stream" and analogous to a wind farm of water-pushed turbines is such a new technology that there is only one deployment in the world that's generating more than one megawatt of energy. One megawatt is enough to power about 1,000 average homes. The Electric Power Research Institute released a study in 2006 concluding that the Golden Gate has the potential to generate 237 megawatts but suggesting that only 15 percent of that about 35 megawatts would be available without negative environmental impact.
"I think that number's made up, personally," said Mike Hoover, a partner at Golden Gate Energy. "We know the energy that's coming in and out of the bay is more than that."
URS, which has conducted no other tidal power studies in the United States, may support those findings, but the outlook at this point doesn't bode well. "It appears EPRI used optimistic assumptions on water velocities," the SFPUC's Power Enterprise director, Barbara Hale, wrote to officials in the Mayor's Office and at the SFPUC and the SFE. "Our feasibility study estimates around 10 MW extractable power, peak, and five MW on average with a commercial plant." Additionally, Hale wrote, the cost per kilowatt-hour could be closer to 20 cents than the 5.5 cents the EPRI predicted.
Hale told us it's difficult to say how much power would make dropping a pilot project into the bay feasible, and the best-case scenario has a pilot project four or five years away. An actual grid connection of any significance would be several years in the future.
Then there's the huge issue of who would own the power. San Francisco Bay is considered a public trust and under any reasonable policy scenario, the power generated by its tides should belong to the public.
After hearing about the mayor's handshake with PG&E, Mirkarimi introduced legislation at the June 19 board meeting that would require any power harnessed in the bay to be publicly owned. He said tidal technology is still at an "embryonic stage," but the memorandum of understanding "that was unilaterally devised by the mayor and the PUC at the exclusion of the Board of Supervisors demonstrates an early intention to give the new technology to the profiteers, and that alarms me."*