Smart Takes

Aquamarine Power's Oyster 2: Can it help wave energy go commercial?

Aquamarine Power's Oyster 2: Can it help wave energy go commercial?

Posting in Design

Aquamarine Power last week unveiled the Oyster 2, a wave energy converter that brings the world's first commercial wave farm a step closer to reality.

Aquamarine Power last week unveiled the Oyster 2, a wave energy converter that brings the world's first commercial wave farm a step closer to reality.

The 800-kilowatt device is 250 percent more powerful than its predecessor, the Oyster 1, the company says.

The company plans to deploy three Oyster 2s at the European Marine Energy Centre in Orkney, Scotland in summer 2011, linking them to a single onshore 2.4-megawatt hydro-electric turbine.

A small farm of 20 Oyster 2s would provide enough energy for more than 12,000 homes, Aquamarine says.

"The design concept remains exactly the same, but we have improved every element of that design, from the size and shape of the Oyster flap, to the hydraulic power take off and pipeline system," CEO Martin McAdam said in a statement.

"Oyster 2 has very few moving parts, and the hydraulic elements are modular, meaning they can be swapped in and out as maintenance is required," McAdam said.

Here's how it works: The Oyster is anchored to the seafloor several hundred meters offshore, where "near-shore" waves trigger its hinge flap mechanism. That in turn engages two hydraulic pistons linked to hydroelectric plants onshore.

Functioning like a pump, the pistons push high-pressure water onshore to drive a conventional hydro-electric turbine.

Here's a video showing how it works:

You can also view an illustration of the system, as well as a full-scale photo (it's much bigger than you think it is.)

Central to the device's appeal are "near-shore" waves. Near-shore waves 0.5 to 2 kilometers (or approx. 0.3 to 1.25 mi.) from the coast carry 80 to 90 percent of the usable energy of waves further out, according to research by Matt Folley of Queen's University, Belfast, as published in the New Scientist.

The question is whether the device is efficient enough to justify its cost. If I understand it correctly, the Oyster keeps the cost onshore, making for a cheaper device -- or, at scale, 100-megawatt farms -- out at sea.

Development of the Oyster 2 was funded by the Marine Renewables Proving Fund via the Carbon Trust.

Share this

Andrew Nusca

Editor Emeritus

Andrew Nusca is editor of SmartPlanet and an associate editor for ZDNet. Previously, he worked at Money, Men's Vogue and Popular Mechanics magazines. He holds degrees from the Columbia University Graduate School of Journalism and New York University. He is based in New York but resides in Philadelphia. Follow him on Twitter. Disclosure