Renewable Energy in Scotland - Wave Power

Wave Power

Various systems are under development at present aimed at harnessing the enormous potential available for wave power off Scotland's coasts. Pelamis Wave Power (previously Ocean Power Delivery) are an Edinburgh-based company whose Pelamis system has been tested off Orkney and Portugal. Their second generation P2 Pelamis machines are 180 metres (591 ft) long and 4 metres (13.1 ft) diameter. Five tubes joined together by hinged joints float semi-submerged on the surface of the ocean and move relative to each other as waves pass down the length of the machine. This motion is resisted by hydrulic cylinders which drive generators inside the machine to produce electricity. Future wave farm projects could involve an arrangement of interlinked 750 kW machines connected to shore by a subsea transmission cable.

Another approach is used by the LIMPET 500 (Land Installed Marine Power Energy Transformer) energy converter installed on the island of Islay by Wavegen Ltd. It is a shore-based unit and generates power when waves run up the beach, creating pressure inside an inclined oscillating water column. This in turn creates pneumatic power which drives twin 250 kW the generators. Islay LIMPET was opened in 2001 and is the world's first commercial scale wave-energy device. The manufacturers are now developing a larger system in the Faroe Islands.

Funding for the UK's first wave farm was announced by the then Scottish Executive on 22 February 2007. It will be the world's largest, with a capacity of 3 MW generated by four Pelamis machines at a cost of over 4 million pounds. The funding is part of a new £13 million funding package for marine power projects in Scotland that will also support developments to Aquamarine's Oyster and Ocean Power Technologies' PowerBuoy wave systems, AWS Ocean Energy's sub-sea wave devices, ScotRenewables' 1.2 MW floating rotor device, Cleantechcom's tidal surge plans for the Churchill barriers between various Orkney islands, the Open Hydro tidal ring turbines, and further developments to the Wavegen system proposed for Lewis as well as a further £2.5 million for the European Marine Energy Centre (EMEC) based in Orkney. This is a Scottish Executive-backed research facility that has installed a wave testing system at Billia Croo on the Orkney mainland and a tidal power testing station on the nearby island of Eday. At the official opening of the Eday project the site was described as "the first of its kind in the world set up to provide developers of wave and tidal energy devices with a purpose-built performance testing facility."

The Siadar Wave Energy Project was announced in 2009. This 4 MW system was planned by npower Renewables and Wavegen for a site 400 metres off the shore of Siadar Bay, in Lewis. However in July 2011 holding company RWE announced they were withdrawing from the scheme, and Wavegen are seeking new partners. In early 2010 two areas were identified for substantial offshore wind development, in the Moray Firth basin and outer Firth of Forth. Shortly afterwards the Government earmarked eleven sites they expected to benefit from the construction of up to 8,000 offshore turbines by 2020. These included Campbeltown and Hunterston, four sites previously used for offshore oil fabrication at Ardersier, Nigg Bay, Arnish and Kishorn and five east coast locations from Peterhead to Leith. In May 2010 the "Vagr Atferd P2" Pelamis 750 kW system was launched for testing by EMEC. The device weighs 1500 tonnes and is 180 metres long.