Wavegen Limpet Oscillating Water Column Device.
The Limpet (Land Installed Marine Power Energy Transformer) is operating on Islay, an island located off the Scottish Coast. It provides the islanders with a combined output of 500kW.
It is an Oscillating Water Column device which uses the power of the waves to produce compressed air in a chamber. The air drives a couple of Wells turbines which incorporate power generators, developed by Professor Wells of Queens, Belfast.
The Wells turbine is designed to turn in the same direction whether it is being rotated by drawing incoming air, or being driven by air produced by the waves.
The Limpet was constructed from concrete in a natural gully on the Islay coast. This location was chosen for its proven ability to operate constantly through supplying large quantities of wave energy regardless of the status of the tide.
As the waves advance into the chamber they push the air through wells turbines, and as the waves recede they draw ambient air through the wells turbine rotating the integrated generators.
If you have ever stood on top of a cliff on the coast with a blow-hole connected to the tide, you will have heard the whoosh of air being expelled as the water level rises and falls due to the wave’s energy. This is the simple innovative operating principle of this Oscillating Water Column Device produced by Voith Hydro Wavegen of Inverness.
They have installed another Limpet in the Faroe Islands and are in the process of developing a larger version of this onshore OWC which will be capable of delivering 100MW of power. The company have their own test centre in Inverness which they use as well as the Orkney Limpet to test various components used in floating offshore OWC devices such as The Osprey. This device consists of a vertical caisson in which the water rises and falls, driving larger Wells Turbine generator units.