Wind power goes underwater

Warwickshire wind power technology company FutureEnergy has adapted one of its generator units to help harness tidal power.

The company's five-blade glass-filled nylon rotor and permanent magnetic generator have now been fitted to a 1/10th-scale prototype of the award-winning Evopod tidal energy device which will soon be undergoing extensive testing in the North Sea. The technology was originally designed to maximise the efficiency of its 1KW low-cost high-power wind turbine,

The brainchild of marine engineers Overberg and developed by Ocean Flow Energy, and winner of the North East 'Innovative Product of the Year' award 2006, Evopod is an innovative design of free-floating tidal generator that converts the motion of tidal streams and ocean currents into electricity for direct feed into the on-shore power grid.

One of Evopod’s advantages over standard tidal generators is its widespread use of existing marine technology and off-the-shelf components which significantly reduces its cost. Evopod is particularly suitable for use in exposed deep-water sites subject to severe wind and wave conditions. Here its free-floating semi-submerged nacelle housing the gearbox and generator, its simple mooring system and single slow moving rotor together limit its impact on sensitive seabed eco-systems and danger to marine life.

Costing just £5,000 to build, the 1/10th-scale Evopod features a 1.5m diameter turbine and has a maximum power output of 1KW, while the full-size version will feature a 15m turbine with a rated output of up to 1500KW, dependent upon tidal stream conditions. FutureEnergy says it would have a fully installed cost of under £1500 per kilowatt.

FutureEnergy estimates that a 1km² area of seabed, in an area such as the Pentland Firth, fitted with 39 1500-kilowatt Evopods would generate sufficient clean energy to meet the electricity needs of 40,000 homes.