How do you generate electricity from waves?

21st October 2010
Waves

Asked by: ANON

As pressure to find sustainable, ‘clean’ methods of energy production mounts, engineers are seeking to harness the power of waves. Waves are more predictable than the wind and hold a huge store of untapped energy. Scottish company Pelamis Wave Power is among those tapping into that energy. Three of its 750kW wave-power machines were part of the world’s first commercial ‘wave farm’, which opened off the coast of Portugal in 2008. That project is now closed, but Pelamis’s P2 was recently named as one of the machines that will be used at three of the six UK offshore sites. The machines will be located 5-10km offshore, where the water is 50-150m deep. Each machine is made up of a series of cylindrical sections, up to 38m long and 4m in diameter, linked by hinged joints. It is ‘slack moored’ so it can swing freely, naturally aligning itself at right-angles to oncoming wave fronts. The UK has about 1000km of Atlantic coastline. The average potential energy of Atlantic waves is 40kW per day for every metre of coastline, which is enough to power around 20 domestic kettles. So, scaling up, 65 P2 machines could generate almost 50MW of power – enough to power up to 33,000 homes a year.


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