Marine Energy - Wave Power

Wavegens Limpet device on the Islay shoreline

Argyll and the Islands has nearly every type of renewable energy production going on within its borders and wave power is no exception. The first commercial wave generator in the world is situated near the small hamlet of Portnahaven on the Isle of Islay. Limpet is the brainchild of a innovative Scottish company, Wavegen, based in the Highland capital of Inverness.
The machine is an Oscillating Water Column (OWC) device were the wave action produces a column of water inside the device which in turn produces pneumatic pressure in an air chamber above the column. It is the air which turns the two counter rotating turbines linked to the generators, each of which can produce 250kWs of electrical power giving a total installed capacity of 500kW.

The OPD Pelamis Wave Energy Converter

Wavegen are now looking to test new nearshore OWC devices and their breakwater turbine either on Islay or at the Network funded European Marine Energy Centre (EMEC) on Orkney. EMEC is also the test bed for Ocean Power Delivery's Pelamis wave machine, another Scottish company leading the field in the marine energy sector. OPD have concluded sea trials of their P-750 device and it was moved to its new test bed at EMEC in August 2004 to coincide with the official opening of the EMEC facility. Since then they have become the first company in the world to receive an order for a fully commercial wave farm consisting of 3 P-750 wave energy converters in May 2005 . The devices have been ordered by a Portuguese consortium led by Enersis and represent the first phase of a wave farm to be located 5km off the Portuguese coast at Povoa de Varim. The initial installed capacity of 2.25MW will gradually be increased to 20MW by the addition of 27 more P-750s. The OPD Pelamis device has attracted interest from all over the world and future deployments are being considered for the state of Maine in the US and in Scotland itself. The Portuguese deal represents a major breakthrough for Scottish company Ocean Power Delivery and a significant leap forward for the worldwide wave power industry in general.      
The latest developer to sign up with EMEC is the Finnish company, AW Energy Ltd from Helsinki, who will be testing their unique underwater WaveRoller device. This is a near shore machine which operates on utilising the ‘bottom wave’ phenomenon. Basically an underwater wing which is attached to a hydraulic arm and uses the backwards and forwards underwater pressures produced by surface waves as they enter shallower waters.
The company was formed by a team of Finnish divers who were aware of this phenomenon and thought that it could be utilised to produce renewable energy generation.

Diagram of WaveRoller array on seabed. Courtesy of AW Energy Ltd, Helsinki. AW Energy

Other companies involved in the international wave energy market are AquaEnergy Group from the USA and Denmark's Wave Dragon ApS with their Aquaboy and Wave Dragon devices respectively.

The potential for Scotland to retain the manufacturing capability and the intellectual property for the Scottish based devices should not be underestimated and Argyll with its considerable shoreline and wave regime could see future benefits from the deployment of these technologies.