Seattle-based Oscilla Power is developing utility-scale wave energy harvester prototypes, each capable of powering hundreds of homes.

"The west coast is really where the goldmine is in the U.S.—where you've got great, high-energy waves and growing demand for electricity," says CEO Rahul Shendure.

The company's prototype, the Triton, uses an electromagnetic process called magnetostriction. A floating platform houses generators made of a custom metal alloy. Tethers connect that to a heavy ring called a heave plate.

At full scale, each Triton system will be 30 yards wide and able to power more than 650 homes. Image credit: Oscilla Power."The heave plate actually wants to sit still," says Shendure. "And what results are changes in tether tension that happen continuously as waves interact with the device. And it's that tethered tension change that we tap into to create electricity."

The company has several rounds of tests under their belt, both in indoor tanks and in open water. And while the Triton is a sturdy system with few moving parts—rugged enough to stand up to harsh seas with little need for maintenance—the technical challenges are daunting, as pounding surf and corrosive salt water are tough on machines.

"It's a very multi-disciplinary engineering problem," says Tim Mundon, director of marine operations. "You have hydrodynamics, mechanical engineering, civil structures, electrical engineering, composites, materials science—all sorts of different areas that have to come into play in order to make something that works.

Moreover, the technology has to do more than just work; it has to do so at the right price. "For wave energy to do what it's capable of doing, costs need to come down on the order of 10-15 cents a kilowatt hour or lower," says Shendure.

The team plans more tests with increasingly larger and more sophisticated prototypes. At full scale, each Triton system will be 30 yards wide and able to power more than 650 homes.