Abstracted from Renewable Energy World, Vol. 4, Jan-Feb 2001, pp18
The Scottish island of Islay is the site of LIMPET, the world's first commercial wave power station, which began to feed electricity in to the UK national grid last autumn. LIMPET - Land Installed Marine Powered Energy Transformer - has been jointly developed by Queen's University Belfast and company Wavegen, after a small experimental station had been established on the island 10 years ago by Queen's. The system in use at the plant is an oscillating water column (OWC), sited on the shoreline in a specially excavated hole behind a natural rock bund - an unusual but successful variation on conventional OWC installation. Inside the OWC, waves create air movements that drive a pair of self-rectifying, contra-rotating Wells turbines, which in turn provide power to the grid. The simplicity of the turbines and the installation process leads to high reliability, with an estimated 60- year service life. Installed in rubble mounds or breakwaters, the unit could also find use as a form of coastal protection. Although relatively small in scale, with a capacity of 500 kW, LIMPET represents the first application for an emerging technology with a great deal of potential. Already, the project has a contract to supply Public Electricity Suppliers for 15 years.