Despite several public pledges and an ongoing civic discussion about harnessing the Golden Gate's enormous tidal differential as a provider of power for the city of San Francisco, we have yet to see any such system operational in the San Francisco Bay, even on a test or demonstration basis.
Now it seems we've dragged our feet too long and lost this particular renewable race: the first large scale wave energy farm has its first three generators up and running. Located off the northern coast of Portugal, the Agucadoura generator is a public-private joint venture between a consortium of developers and manufacturers and the Portuguese Energy utility. The three generators (a single generator is shown above) produce ~0.84MW each (for comparison, the average wind turbine currently operational in California produces ~0.03MW). Once the farm is complete, it will produce 22.5MW of energy.
O great Golden Gate, you too will power the citizens that love you...some day.