Wave Energy...Revisited

Over the last decade, wave energy has had its ups and downs…technically as well as financially. Many of the problems with earlier designs were related to the fact that they focused on areas where the seas were most energetic. Enduring these extreme conditions requires bulky platforms that are expensive to build and costly to deploy and maintain.

But a new type of system (rated at 150 kilowatts) was recently installed off the coast of Italy. It promises to make harvesting energy from the ocean swells less expensive and more robust by sitting below the surface, where it’s not subjected to extreme weather, but can still capture energy, albeit at lower amounts. Two buoyant sections are mounted at different depths, with one moored to the sea floor. The sections are connected by arms that move inside each other like a giant piston to generate power. The entire module can also adjust vertically to get out of the way of severe storms.

Another advantage of this design is that it produces a more consistent output, which is helpful to utility operators looking to integrate renewables into the power grid.