Oscillating water column
The OWC operates by changing water levels and pressure in an open chamber with the fluctuations of water from the waves. The change in pressure forces air through a bi-directional Wells turbine creating pneumatic power. This is converted into electrical power using a generator with required control and protection equipment to achieve a grid acceptable output. The figure of the LIMPET OWC (to the right) and the video on the Home page helps visualise the concept of operation.
History
The first trials of OWC technology dates back to 1983 in Japan (Sanze) and 1985 in Norway (Toftestalan). In 1988 Japan Marine Science & Technology successfully tested a floating OWC The Mighty Whale for two years.
OWCs are relatively new in the European commercial power generation sector with Voith Hydro Wavegen installing and developing ‘shore-mounted’ or breakwater OWCs such as LIMPET (2001) and Mutriku (2011); these are grid connected. Floating OWCs have yet to reach commercial scale and prototypes have recently been developed by Ocean Energy and Oceanlinx. Potential
The Carbon Trust have assessed the UK’s coastline wave power resources highlighting North West Scotland, the North coast of the South West of England and the Shetlands and Orkney Islands as having potential for development, as shown in the figure on the right; a “potential of 8km of shoreline OWCs” in the UK (The Carbon Trust, 2005). This high potential is due to the Atlantic Ocean having a long fetch (the length of which the wind blows over the sea surface) to produce an energetic wave climate.
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