Recently Edinburgh-based company Aquamarine Power unveiled plans to install a new type of wave power system in place in the seabed off the Orkney Islands coast.
Aquamarine Power’s Oyster wave power technology captures energy in nearshore waves and converts it into clean sustainable electricity. Essentially Oyster is a wave-powered pump which pushes high pressure water to drive an onshore hydro-electric turbine.
Wave power is generated by wind blowing over the surface of the ocean far out at sea. The action of the wind transmits energy into waves. These waves can travel vast distances with little energy loss before breaking on the shore. Our Oyster device is designed to harness this energy and convert it into electricity.
Mechanical offshore device
The Oyster wave power device is a buoyant, hinged flap which is attached to the seabed at depths of between 10 and 15 metres, around half a kilometre from the shore. This location is often referred to as the nearshore.
Onshore electricity generation
Oyster’s hinged flap, which is almost entirely underwater, pitches backwards and forwards in the nearshore waves. The movement of the flap drives two hydraulic pistons which push high pressure water onshore via a subsea pipeline to drive a conventional hydro-electric turbine.
In the future, subsea pipelines will connect multiple Oyster wave energy devices to a single onshore plant. Ultimately Oyster will be installed in wave farms of several hundred connected devices generating hundreds of megawatts of electricity.
By locating Oyster in the nearshore, we are able to capture a high proportion of the energy available in the ocean whilst avoiding the severe storms which occur further out to sea.
Proving Oyster works
We have conducted over five years of rigorous testing of the Oyster concept at 25th and 40th scale in the wave tank at Queen’s University, Belfast. In 2009, we commenced sea trials of our first full-scale Oyster prototype – known as Oyster 1. With the operation of Oyster 1, we have demonstrated the feasibility of the Oyster concept. Oyster 1 has gone on to deliver over 6000 operating hours.
Installation of Oyster 2
We have now commenced our second Oyster wave power project – known as Oyster 2. Oyster 2 will consist of three Oyster wave energy devices installed at sea in a configuration known as an array. We will install one Oyster wave energy device at Billia Croo in Orkney this summer. We plan to install two further Oyster devices in the same location in 2012. Our Oyster 2 wave power project will demonstrate the feasibility of installing multiple Oysters in small arrays and ultimately in larger wave farms.