Irish Company OceanEnergy’s OE35 is the World’s Largest Floating Wave Energy Device
Floating on the ocean’s surface, the device incorporates a trapped air volume, with the lower part open to the sea. Wave pressures at the submerged opening cause the water to oscillate and drive the trapped air through a turbine to generate electricity. This energy can be exported to the grid.
What is Different About the OE35 Wave Energy Converter?
A number of existing wave energy devices have encountered barriers to commercialisation. Prominent among these are:
- The difficulty of scaling up devices to generate large amounts of power, and therefore to drive down the cost of the electricity they produce.
- Being robust enough to withstand the huge forces that waves can exert, together with the corrosive effect of saltwater on moving parts.
The OceanEnergy OE35 wave energy converter overcomes these issues:
- It can be built at scale. The latest version is more than five stories high and weighs over 800 tonnes.
- The only moving parts in the device sit well above the waves, making them much less prone to damage and corrosion.
- The dynamic response of the device in large waves results in reduced mooring forces thus increasing the inherent survivability.
How Does the OE35 Work?
The technology (which is known as OE Buoy) is based on an oscillating water column device. The lower part of the device is open to the sea, which traps a large volume of air inside the device. As the waves oscillate, this forces air pressure inside the device, which is used to drive a built-in turbine to generate electricity. Furthermore, the OE35 can generate electricity not only when waves crash into it, but also when they recede, thanks to a component known as a Wells turbine.
When the water recedes, it creates a vacuum and air rushes in to fill it, keeping the turbine spinning in the same direction, and the cycle repeats. The only moving part is the turbine rotor, which is above the waves.
For the WEDUSEA project, the OE35 will be adapted to work in the Atlantic ocean conditions at the European Marine Energy Centre Billia Croo test site in Orkney. This will involve some innovative modifications, including to the hull design.
A brief animation sequence, which brings to life how the OE35 works.
A previous version of the OE35 under construction, showing the size and scale of the device.
