A ridge that rises high above the Bay floor east of the Golden Gate Bridge has been identified as the likely site for a pilot project that could power homes and businesses by capturing the power of the tides.
San Francisco has spent around $80,000 of city funds since June to investigate whether renewable energy could be generated from the powerful moon-pulled tides that race twice a day through the Golden Gate, according to San Francisco Public Utilities Commission spokesman Tony Winnicker.
The study, expected to be released later this month, found that an underwater turbine placed on the 150-foot high ridge could generate enough clean energy to power 1,000 to 2,000 homes during peak tide currents, according to figures provided by Winnicker.
But the cost of the energy would be more than six times the price of traditional fossil fuel-generated electricity currently sold by Pacific Gas and Electric, according to figures provided by Winnicker.
Further, a recent study conducted for Tacoma, Wash., concluded that that city should wait another five to 10 years before developing tidal power because of high costs and limited development of current technology.
Scientist Jen Kovecses, of the environmental group Baykeeper, said the area beneath the Golden Gate Bridge is a popular migration route for fish and other creatures and that a poorly designed turbine could kill the animals or disturb them with never-ending noise.
Compounding those setbacks, San Francisco Environment Director Jared Blumenfeld said The City previously thought the Bay would be one of the world’s 10 best sites for generating tidal power, but it now appears that it is one of the world’s hundred best sites.
Despite the setbacks, Blumenfeld said he expects The City to forge ahead with a pilot study using animal-friendly turbines placed on the ridge near the Golden Gate Bridge.
“If we want to be a hub of innovation when it comes to renewable energy, we really have to put our money where our mouth is and develop at least a demonstration site,” Blumenfeld said. “Even if we don’t fund a penny of it, we’ve spoken to a lot of investors that are really interested.”
Mayor Gavin Newsom, who announced his support for tidal power in June, on Tuesday said he remained supportive of the technology and would “fight for it.”
The City has also started a project to investigate whether it can create electricity from wave power at Ocean Beach and applied for state grants to investigate whether it can create geothermal energy from heat trapped beneath the surface of the Earth, Blumenfeld said.
Proposed tidal pilot study
» 60-foot wide turbine placed 2,000 feet east of Golden Gate Bridge
» Currents at site range up to 8 feet a second
» Could create 1.2 million kilowatt hours per year.
» Installation cost: $12 million to $15 million
» Annual operating costs: $250,000 to $750,000
» Electricity price: $0.85 to $1.40 per kilowatt-hour
Source: San Francisco Public Utilities Commission