From big rubber electric eels to 17 terawatt super dams, wave/tidal power may be the most creative pool in renewables. The newest depth charge in the water wars is the PowerBuoy from Ocean Power Technologies. Their simple device uses the natural bobbing motion of these most favorite of seagull rest stops to drive a piston and generator setup.

The company deployed two of their buoys for the U.S. Navy in the past couple weeks, located off the coasts of Hawaii and New Jersey. In fact, the Navy seems to be OPT's biggest customer by far, especially now that they've just landed a $3 million contract with them.

Besides being the waterbound branch of our military, why is the Navy so swayed by the technology? Essentially, they plan to use the beacons as self-powered, floating surveillance stations. The Deep Water Active Detection System (DWADS) program seeks to establish sophisticated data gathering and communications for homeland security applications such as "vessel tracking". Who knew wave power was so Hunt for Red October?

OPT says their technology compares well to other renewables, since ocean currents are highly predictable and the PowerBuoy can produce electricity at an estimated 5-10 cents per kWh. The buoys may also prove to be less controversial than, say, a wind farm due to its low profile. Other benefits include their high scalability and ability to be located well offshore (the one in NJ is in 3,300 ft deep water).

Currently, a single PowerBuoy, measuring 12 feet in diameter and 55 feet long, can produce up to 40 kW, but the company is working on a 150kw version. Other OPT projects underway are a $2 million Department of Energy contract and a 1.4 megawatt installation in Spain.

My take is that buoy-power could find a nice niche in the wave energy ecosystem, but will most likely be used for small installations and the kinds of remote applications being pursued by the Navy.