Navy Uses Waves to Power Sensors

An array of buoys that track vessel movement off the coast of New Jersey is being powered by ocean waves. Larry Greenemeier reports

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Like most renewable energy sources, ocean waves cannot compete with the low costs of fossil fuels. It’s expensive to get wave-generated electricity ashore and add it to a local grid. But what if wave-energy conversion could be used where it’s generated?

The U.S. Navy aims to find out. A few weeks ago it installed a system of what are called PowerBuoys, made by Ocean Power Technology. The buoys are bobbing in the Atlantic about 30 kilometers off the New Jersey coast. Each one contains hydraulic fluid and a generator.

Ocean waves move the hydraulic fluid, which spins the generator. Depending on wave height and speed, as well as wavelength and water density, each buoy can produce up to 40 kilowatts of electricity.

Rather than transmitting that electricity to shore over a submerged fiber-optic line, the juice will power the ocean-based sensors that detect and track vessels. The system is part of the Navy's near-coast anti-terrorism and maritime surveillance program.

The PowerBuoys will replace ecologically unfriendly diesel generators. If only they could replace the cast of Jersey Shore.

—Larry Greenemeier

[The above text is a transcript of this podcast.]

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