Tidal

Since 2003, the Seaflow 300kW experimental tidal flow turbine has been in operation 3km offshore from Lynmouth – a world record. No other marine renewable energy has worked in an offshore environment for this length of time before.

Marine Current Turbines’ Bristol head office has monitored the turbine, which has worked reliably and automatically. The Seaflow turbine has gathered important data that will help in the design of the 1MW commercial prototype, Seagen, which will succeed it.

www.marineturbines.com/news.htm

Seaflow project Photo courtesy of Marine Current Turbines Ltd

Stingray
Sullom Voe, Shetland

Stingray is a totally submerged, offshore device that consists of a hydroplane (an underwater wing) fixed to a system of levers that operate a pump. The angle of attack of the hydroplane is altered by a simple device and as the tidal flow passes over the hydroplane it moves up and down and operates the pump to produce high pressure oil. This oil is then used to drive a hydraulic generator. Stingray is still a prototype but when fully developed would operate in farms of many such devices in suitable areas of the ocean floor.

You can see the power of the tides around the UK here www.britishwindenergy.co.uk (click on the spring tidal power map). This map shows the energy in kW/m of spring tides in UK waters. The most powerful tides are off headlands – look at the figures for narrow channels. But we also find powerful tides in shallower waters – off East Anglia and in the English Channel.

Spring tides are the highest and most powerful tides and happen once a month (they have nothing to do with spring as a season, but are caused by the moon's rotation around the Earth). The opposite of a spring tide – when tidal energy is at its lowest – is a neap tide.

www.bwea.com/marine

New and Renewable Energy Centre
Blyth