By the end of the year, twin underwater turbines should be generating 1.2 megawatts of electricity off the coast of Northern Ireland in a landmark demonstration of tidal power technology.
, a company based in Bristol, UK, had hoped to begin installing the turbines at () on Monday, but the construction barge scheduled to deliver the turbines was delayed. A company spokesman says the installation will now take place later in 2007. It will be the world鈥檚 largest tidal power project.
The underwater turbines look and work very much like wind power turbines. Each blade is 15 to 20 metres across and is mounted on an axis that attaches to a 3-metre-wide pile driven into the seabed.
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Tide-driven currents will move the rotors at speeds of between 10 and 20 revolutions per minute, which the company claims is too slow to affect marine life. The turbines will drive a gearbox that will, in turn, drive an electric generator and the resulting electricity will be transmitted to the shore via an underwater cable.
The Strangford Lough tidal generator is intended purely as a demonstration project. Eventually, MCT intends to build farms of turbines consisting of 10 to 20 pairs each.
Each turbine requires a piece of equipment called a jack-up barge for installation. The barge anchors itself to the sea floor and drills a hole that sets the turbines in place.
鈥淥f the 60-odd [tidal power] projects I鈥檝e seen, this seems like the best,鈥� says , a professor in technology policy at the Open University in Milton Keynes, UK.
鈥淚t鈥檚 an interesting period,鈥� Elliott adds. 鈥淵ou have lots of approaches and lots of innovative projects. The straightforward underwater propeller seems like the winner.鈥�
Elliott says that tidal and wave power could eventually provide between 15% and 20% of the UK鈥檚 electricity needs. But he believes that operators need to develop experience with the technology before the price of energy generated in this way falls to levels comparable to wind power.
