This is an excerpt from EERE Network News, a weekly electronic newsletter.
Prototype Tidal Power Plant Installed Off U.K. Coast
A 150-kilowatt generator powered by tidal streams was installed in about 120 feet of water in Yell Sound in Scotland's Shetland Islands on September 13th. The $2.8 million project marks the world's first offshore installation of a full-scale tidal stream power plant. According to The Engineering Business Limited, which designed and built the generator, tests of the generator over the weekend produced "significant power output."
The tidal power generator, called the Stingray project, features a 15-meter-wide (49-foot) hydroplane mounted on a supporting arm that pivots on a large support structure. To draw power from passing tidal streams, a device constantly changes the tilt of the hydroplane, causing its supporting arm to oscillate. Each oscillation extends and contracts hydraulic cylinders in the supporting arm, pumping oil to drive an electric generator.
Yell Sound, a north-facing inlet at the extreme northern tip of the United Kingdom, is expected to be an excellent site for tidal flow energy, with spring tide velocities in excess of 5 knots. The demonstration project is receiving support from the U.K. Department of Trade and Industry and is expected to operate for one year.