CalWave’s Underwater ‘Carpets’ Harness Wave Power

A Berkeley Lab project goes power surfing
Source: CalWave

Innovator: Marcus Lehmann
Age: 28
Leads the year-old CalWave project at Lawrence Berkeley National Laboratory in California

Form and function
CalWave, an underwater mechanism of springy fiberglass “carpets,” generates electricity from ocean waves more efficiently and less obtrusively than wave-energy systems at the surface now in use in Hawaii and other places.

Building on a concept from one of his professors at Berkeley, Lehmann assembled his first prototype in 2012, while earning his master’s in mechanical engineering. He bought parts from and a local hardware store.

Lehmann and project partner Maha Haji have raised almost $530,000 in seed money from Berkeley, crowdfunding, and competition prizes.

Illustration: 731

1. Flow: The CalWave carpets, 30 feet to 60 feet underwater, undulate as waves pass over them, driving pistons anchored below.

Illustration: 731

2. Dual use: CalWave is developing two versions of its system: one that powers a hydraulic motor to generate electricity and another in which the pistons drive seawater through the membranes of a desalination plant.

The U.S. Department of Energy estimates that recovering 5 percent of the energy from ocean waves could power 5 million homes.

Ramping up
In 2013, CalWave’s second prototype topped 50 percent efficiency in converting wave energy to power.

Next Steps
CalWave plans to switch on an 8-foot-by-30-foot prototype plant off the San Diego coast late this year. Lehmann says it will cost about $80,000 to build and generate 80 kilowatts of power, enough to run 180 homes. For commercial operations, multiple units will link together to form wider carpets. Lehmann and Haji are talking with IDE Technologies, which is building a $1 billion desalination plant in Carlsbad, Calif., about using CalWave as a power source.

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