World's first floating wind turbine to be built in North Sea

Wednesday, June 27, 2007

The world’s first floating wind turbine could be up and running in under two years after the German engineering giant Siemens teamed up with a Norwegian energy group yesterday to try to generate electricity in the middle of the North Sea.

If successful, it could prove the perfect solution for environmental campaigners, confronted with a public that like the idea of wind power but think wind turbines are an eyesore.

And it is something the engineers behind the ground-breaking project are also keen to stress.

“It’s attractive to have windmills out at sea. We can produce a lot of energy, out of sight,” said Alexandra Bech Gjoerv, the head of the energy division at Norsk Hydro, the Norwegian firm spearheading the project.

Wind turbines at sea are nothing new, but until now they have had to be sited in shallow waters so the bases could be fixed to the seabed. This not only means complicated and costly construction but also visual pollution, as the rotating blades can be seen from the shore.

The demonstration turbine, set to cost 200m Norwegian kroner (£17m), will be eventually floating near the island of Karmoy, southwest of Norway. “It’s a logical step,” Walt Patterson, an energy expert at the Chatham House think-tank in London, said. “Floating turbines will be easier to make because you can do most of the fabrication on land and then float it out to sea.

“The turbine will be much better placed. Further out to sea you have a much stronger and more reliable wind supply as you don’t have trees, hills and buildings sticking up and getting in the way, although you do need to worry about stability and making sure the thing stays standing.”

Hydro’s design is a concrete base acting as ballast for 200-metre steel tube, of which about half will poke out of the water.

Keeping it secure in the North Sea, where waves can reach 30m in height, are three cables that loosely anchor the base to the seabed. The technology is much the same as that used for offshore oil platforms, only with much greener credentials.

Engineers expect that the floating turbine could work in waters up to 700m deep. The prototype will initially generate about five megawatts of electricity, enough to supply at least 1,000 homes.

“Five megawatts is huge. That would be bigger than anything on land or offshore in operation at the moment,” Professor Ian Fells, the founding chairman of the New and Renewable Energy Centre, said. “It sounds like a great experiment. We need as much renewable energy as we can lay our hands on.

“I only hope they realise that the North Sea is a very hostile environment. It’s extremely corrosive with all that salt, and if anything goes wrong, they will have a devil of a job getting on the machine to repair it.”

If all goes to plan, though, a small offshore windpark with about 200 turbines could be built by 2014, supplying electricity to coastal cities, reducing dependency on fossil fuels and helping to cut greenhouse gas emissions.

Wind power has proved a contentious issue around the world. A proposed wind-farm at Whinash near Kendal was eventually scrapped in the face of public opposition, while on the Greek island of Skyros, residents are fighting to block 100 turbines being built on a nature reserve.

With the floating Norwegian turbine, however, the only people likely to see it and be irked by visual and noise pollution are the seamen on board the tankers that ply the North Sea.