Lieutenant Governor Gavin Newsom says wave power eight miles off the coast of San Francisco is economically feasible and can be done at a cost less than solar power. He originally favored tidal power but "The tidal was bad news. ... The more we learned, the worse it was." Tidal power works by installing giant turbines on the sea bed and using the flow of the tides to generate power. Such power is variable but predictable. No power can be generated when the tides are at ebb. However, the amount of power generated is completely predictable based on the tides. But, the ocean is an unforgiving place, and tidal turbines take enormous punishment from the currents. Hence, development of successful tidal turbines has not been particularly successful.
Wave power, by contrast, is steady power and is created by the motion of waves. While technical challenges still remain, wave power appears to be more promising. A 30 MW test site offshore of San Francisco looks feasible, and Newsom is confident private investors can be found to fund much if not all of it. While no decision has been made on which technology to use, two of the leading companies are Aquamarine Power and Pelamis Wave. Aquamarine Power makes a 160 foot tall oyster-like generator that rests on the ocean floor with the top of the machine just above the waves. The power of the waves drives huge pistons. Pelamis has a 500 foot long device that resembles a snake that sits on the sea surface. It is tethered to the ocean floor and power is created by hydraulic rams.
The wave study for San Francisco suggests that upwards of 100 GW hours of power could be produced at a cost less than solar. This is costlier than traditional power, but as the technology progresses, the cost will drop. Imagine the benefits if California could produce enormous amounts of clean, renewable energy in its own offshore areas without having to transport fuel to create the power from coal mines or oil from overseas. Newsom plans to continue pushing wave power for California. Let's hope his plan succeeds.