Wave energy company Oscilla Power has developed an energy generation system that uses the movement of the ocean’s waves to generate electricity, with the help of magnetic fields. The iMEC power generation system uses magnetostriction alloys to produce “significant quantities” of energy, the company claims.
Magnetostriction is a property of magnetic materials that causes the materials to change shape during the process of magnetization. Magnetostrictive materials are able to convert magnetic energy into kinetic energy, and it’s also what causes the electric hum emitted by transformers.
Oscilla Power’s iMEC technology uses magnetostrictive alloys to convert mechanical energy from the ocean’s waves into electrical energy via reverse magnetostriction — that is, changing the shape of the magnetostrictive materials in order to cause changes in their magnetic characteristics. That magnetic energy is then converted into electrical energy.
The system is comprised of a surface float and a submerged heave plate, connected together with flexible tethers. The wave energy is captured from the heave and pitch motion of the surface float acting against the submerged plate. There are a number of pairs of generators inside the float, up to six pairs in a full-sized deployment. Each pair is attached to one tether, and the generators use the change in tension in the tether as a catalyst of sorts to produce “flux density changes” within the generators. The energy is eventually converted into electrical energy within a coil in the generator.
The company claims its solution is “low-cost, scalable, flexible, predictable, robust and efficient.” The generators inside the float are able to produce hundreds of kilowatts of electricity when combined together, it said.
The biggest advantage to this approach is that the system is simple, easy to deploy and maintain. Wave energy system deployments are currently much more costly than other renewables because the conditions in the ocean are so harsh. The salt water is incredibly corrosive and installations typically have much shorter life spans; and they are also typically much more difficult to reach for maintenance and repair.
The company has already completed tests in the Atlantic Ocean of smaller versions of its system, and in March of this year, Oscilla Power was named one of nine finalists for the US Department of Energy (DOE) wave energy prize.
Watch a video on the Oscilla Power wave energy technology here: