Wind, Wave, Tidal: Renewables Triple Play at Sea
Off-shore wind, wave and tide power are potentially a vast electricity resource for the UK.
According to this article in UK national paper, The Guardian, while wind is now accepted as a "mature technology" that is economically viable, the others are at the expensive development stage - though between them they could produce more energy than wind.
Both wave power machines and tidal power undersea turbines are currently being tested off the coasts of Britain.
A separate article in the Scotsman quotes Peter Simpson, a consultant with the wind energy consultancy Garrad Hassan & Partners, who argues that the days when people could dismiss offshore wind projects as far too expensive in comparison to onshore projects are over. Simpson led an assessment into offshore wind for the government more than ten years ago. "At the time, we came up with costs that were 60 per cent higher than the costs for similar land-based projects. Today, the offshore costs are still above onshore costs, but the gap is no longer a significant one," he says.
Simpson points out that one 600kW wind turbine at a reasonable site would produce enough electricity to meet the annual needs of 375 UK households, and a 500MW offshore windfarm would produce enough electricity to meet the annual needs of more than 300,000 UK households.
Twenty-five years ago the biggest bored pile was one metre in diameter. Now bore piles can be five metres in diameter, making off-shore turbines of five megawatts and up possible.
If off-shore wind power, wave power and tidal turbine technologies work, and can be harnessed together out at sea, it will produce significant economies of scale as the same transmission cables can bring the electricity ashore. This combination of three alternative energy power sources could potentially supply all of the UK's electricity needs and also be used in many other countries.