Researchers Look Underwater for New Hydroelectric Source

San Francisco city officials have approved $2 million for a pilot project to test the feasibility of harnessing tidal ebb and flow for generating electricity. The technology being considered was developed by London-based HydroVenturi. It would involve installing a concrete passageway on the floor of San Francisco Bay, through which water would be funneled during tidal changes. The flow of the current would create suction in pipes connected to onshore turbines, causing the turbines to rotate and generate electricity.

The test site is only anticipated to produce 1 MW, but project proponents envision a future grid beneath the Golden Gate Bridge capable of generating up to 2,000 MW, more than twice what the city now requires. Cost for such a system is estimated at $600 million.