Wave energy company Ocean Power Technologies has announced four new contracts that will contribute to the construction of a pilot project off the coast of Oregon, near Reedsport. The contracts involve various parts of OPT's PB150 PowerBuoy.
The first buoy should be in the water by later this year, after which the company plans to build the installation up to be the "first commercial-scale wave power station" in the country. Eventually, there may be as many as ten of the PB150s in the water. This would yield an installed capacity of 1.5 megawatts, at 150 kW per buoy. According to OPT, further additions could someday bring as much as 50 MW. The buoys will be grid-connected once the first batch are installed, and even a 10-MW installation would require only 30 acres of ocean space.
The buoys, which drop more 100 feet below the water's surface and are anchored to the ocean floor, work using a sort of piston mechanism. The top of the buoy rises and falls with the wave motion -- they work at wave heights of 4.9 to 22.9 feet -- which spins a generator. An undersea controller then sends the collected energy along cables to shore.
This is far from the only wave power device in development, but it seems to have the most momentum. One other company, Pelamis Wave Power, does have several projects in development. Their technology is described as follows:
The Pelamis Wave Energy Converter is a semi-submerged, articulated structure composed of cylindrical sections linked by hinged joints. The wave-induced motion of these joints is resisted by hydraulic rams, which pump high-pressure fluid through hydraulic motors via smoothing accumulators. The hydraulic motors drive electrical generators to produce electricity. Power from all the joints is fed down a single umbilical cable to a junction on the sea bed.
And off the coast of Cornwall in the UK, an interesting project seems to be acting almost like a miniature, wave research-oriented version of the promised Atlantic Wind Connection: the Wave Hub, a grid-connected offshore facility, lets companies test their wave power devices without having to develop the infrastructure to send the power back to shore.
Waves, of course, are an infinitely renewable resource, so this is certainly a worthy avenue to pursue. And some estimates [PDF] put the full potential of wave power as high as 2,100 terawatt-hours per year in the US alone.
(Image via Ocean Power Technologies)