What we do in ocean energy

Vattenfall has selected Scotland to start its development of future commercial ocean energy electricity generation. Vattenfall is presently proceeding with, among other things, environmental studies and wave energy evaluations of an area off the Shetland Islands in order to secure authorisation for development from the Scottish authorities.

Scotland

Vattenfall has formed a joint venture company, Aegir Wave Power, together with the Scottish wave power technology company Pelamis Wave Power. Aegir successfully completed negotiations with The Crown Estate in May 2011 to reserve a site of the Southwest coast of Shetland to work toward wave farm development.

Aegir are now getting underway with practical investigation and planning work. A broad program of surveys will be initiated, including wave resource assessment, ecology, archaeology, and navigation risk assessments.

The next step is to invest in a full scale Pelamis machine by the end of 2012 that can be used to prove technical feasibility. If all goes well, Vattenfall and Aegir hope to have the first full-scale wave farm in Shetland cleared for construction by 2015.

Different wave power technologies

Pelamis

Pelamis was the world’s first commercial scale machine to generate electricity to the grid from offshore wave energy. It is a semi-submerged construction composed of cylindrical sections linked by hinged joints. The wave induced motions of these joints Is resisted by hydraulic rams which pump high pressure oil through hydraulic motors that drive electric generators to produce electricity. Pelamis new P2-version consists of four sections with a total length of about 180 m, 4 m in diameter and has a rated power of 750 kW.

Wavebob

Wavebob consists of two floating bodies. By adjusting the water ballast of the submerged tank the two bodies can be made to heave out of phase. The relative motion between the bodies is used to absorb wave energy in the connection point between the bodies. A full scale Wavebob will be around 20 m in diameter, with a 90 m vertical construction below surface and have a rated power of about 1,5 MW.