The British government announced yesterday that it’s scrapping a huge and controversial tidal power project that would have cost up to $48 billion to build, and could have provided clean energy for up to 5 percent of the United Kingdom. It was just too expensive, the government said.
“Other low-carbon options represent a better deal for taxpayers and consumers,” Chris Huhne, secretary of state for energy, said today in a written statement to Parliament in London. The decision, along with separate moves to spur nuclear power, mark out the government’s strategy to replace a quarter of the nation’s electric power stations by 2020. [BusinessWeek]
The project called for harnessing the tidal energy of the Severn, Britain’s longest river, where the river meets the ocean. The Severn estuary has the second largest tidal range in the world (after Canada’s Bay of Fundy), making it seem a natural fit for tidal power. But the project stalled as objections were raised to the five leading proposals. Three options called for enormous dams, or barrages, to be built across the waterway, which environmental groups objected to. Those environmental groups, including Friends of the Earth and a birding group, greeted the news of the project’s cancellation with delight.
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Scotland is getting ready to capitalize on something the country has plenty of: fierce, stormy waves.
About 750,000 Scottish homes expect to be powered by ocean technology by 2020, as the Scottish Government announced that 10 wave and tide power schemes capable of generating up to 1.2GW in total would be built around the Orkney islands and on the Pentland Firth on the northern coast of the Scottish mainland [Guardian]. The 10 projects will comprise the world’s first commercial-scale wave and tidal power scheme. With this project, Scotland plans to produce the same amount of clean energy as a small nuclear power station, and hopes to start on a path to becoming the “Saudi Arabia of marine energy.”
Some of the strongest tidal currents in the world race around UK shores and there’s some of the highest energy in the waves that roll in from the Atlantic. And while wave power is, to an extent, dependent on the weather, tidal power has the tremendous advantage of being totally predictable [Channel 4].
It will cost about $7.6 billion in total to install and maintain the structures used to generate power from the strong waves and tides, and to transmit the energy back to land. The bulk of the work will be done by three major power firms: E.ON, Scottish and Southern Energy (SSE) Renewables, which already operates the UK’s largest hydro schemes, and Scottish Power Renewables, a heavy investor in windfarms, in joint ventures with four of the UK’s leading marine energy firms [Guardian].
Click through the photo gallery to see the wave and tidal devices that will soon get their try-outs in the cold, turbulent waters off the Scottish coast.
Image: flickr / jack_spellingbacon
A marine engineer and naval architect has designed a new way of drawing energy out of slow-moving rivers and gentle tides. The researcher says the unobtrusive device, which was inspired by the way fish move through the water, could be set down on riverbeds or suspended in the ocean just about anywhere. Existing technologies which use water power, relying on the action of waves, tides or faster currents created by dams, are far more limited in where they can be used, and also cause greater obstructions when they are built in rivers or the sea. Turbines and water mills need an average current of five or six knots to operate efficiently, while most of the earth’s currents are slower than three knots [Telegraph].
Engineer Michael Bernitsas’s device is called VIVACE, which stands for Vortex Induced Vibrations for Aquatic Clean Energy. How does the technology work? A cylinder-shaped object in the water current causes alternating vortices to form above and below the cylinder. The vortices push and pull the passive cylinder up and down on its springs, creating mechanical energy. Then, the machine converts the mechanical energy into electricity [Greenbang]. Bernitsas explains that fish also create vortices as they swim, and in a large school each fish curves around the vortices left by the fish in front, using the tiny whirlpools to propel themselves forward.
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The first commercial energy station powered by ocean waves started up yesterday three miles off the Portuguese coast. The machine, which resembles a giant red sea snake, generates electricity that’s transmitted via an underwater cable to the nation’s power grid. Two more machines are expected to be added in the coming weeks, allowing the “wave farm” to generate a total of 2.25 megawatts, enough to supply 1,500 households with electricity [Reuters]. If successful, a second phase will see energy generation rise to 21 megawatts from a further 25 machines providing electricity for 15,000 Portuguese homes [CNN].
Environmentalists love the idea of generating power from the natural motion of waves and tides, as the ocean’s energy is bountiful, reliable, and creates no greenhouse gases. But the technology has been slow to mature. Last year, a wave-power machine sank off the Oregon coast. Blades have broken off experimental tidal turbines in New York’s turbulent East River [The New York Times]. A problem with offshore moorings also delayed the Portuguese project for about a year. But wave power proponents say that some problems are inevitable with a new technology, and that most of the kinks have now been ironed out.
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