Alstom and SEE set to develop wave-energy site off Orkney

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Alstom and SSE Renewables have signed an agreement to develop the Costa Head Wave Project, an up-to-200MW wave-energy site located north of mainland Orkney.

According to a statement, the two companies intend to populate the site with AWS-III wave-energy converters, a technology currently under development by AWS Ocean Energy. 



The Costa Head site is located in water depths of 60–75m approximately 5km to the north of mainland Orkney.

SSE Renewables and Alstom propose to develop the site with an initial phase of around 10MW, before moving on to install the full site capacity. 


Established in 2004, AWS Ocean Energy is focused on the development and delivery of its AWS-III wave-energy converter, a floating device with a rated power output of 2.5MW. Alstom acquired a 40 per cent equity share in the company in June 2011.

Full-scale component testing will commence in 2012, with a full-scale prototype planned for deployment at the European Marine Energy Centre in 2014. 



In use, the AWS-III technology consists of a multi-cell array of flexible membrane absorbers that convert wave power to pneumatic power through the compression of air within cells that are interconnected.

Turbine generator sets are provided to convert the pneumatic power to electricity. 



A typical AWS-III device will comprise an array of 12 cells, each measuring around 16m in width by 8m in depth, arranged around a structure with an overall beam of up to 60m.

The AWS-III will be slack moored in water depths of 65–150m using standard mooring spreads. Devices will be arranged in arrays with a total rating of up to several hundred megawatts and each AWS-III will be connected to a central offshore substation via a high-voltage umbilical link.