Offshore Energy: Germany Plans Wind Parks on the Open Sea
- 00:05:01
- DW-World
Offshore Energy: Germany Plans Wind Parks on the Open Sea
As more and more windy areas on land fill with rotors to convert wind power to electricity, manufacturers are pushing to move their facilities offshore, where the wind is stronger and steadier. Germany has plans to generate 25,000 megawatts of power from offshore wind energy by 2030. That corresponds to 15 percent of electricity use. The Federal Maritime and Hydrographic Agency has given the green light for six wind turbines for commercial use to be built 45 kilometers off the North Sea island of Borkum. The operator will be Alpha Ventus. Ironically, the wind has delayed construction until 2009. But a model plant is being built off the mainland town of Hooksiel. Three pipes, three meters in diameter are being rammed 45 meters deep into the Wadden Sea. Then come the tower, the gondola and the 60 meter long rotor blades. Made in Germany was there to see the giant wind energy plant put together. ______________________________ It is a five-hundred meter trip out into the North Sea to "Giant 4". The heavy-duty steel pontoon was specially hired for this job from a company in Rotterdam. For several weeks, a team of specialists have been working here building Germany's first offshore wind farm. These 55-meter-long foundations piles weigh 200 tons each. Moving them requires very big machines. Even with the help of technology, this is back-breaking work. ... It takes a full day to put each pile in place. Andree Krüger form the firm BARD-Engineering says: "This evening we're going to get the third foundation pile into the winch, position it and lower it about 20 meters. Then in the morning we can start ramming it down into the seabed." But there are still many more hours of hard work until then. The positioning winch consists of a gigantic steel frame. It is designed to keep the foundation pile completely vertical. This is important because once the pile has lodged into the sea floor, it is there to stay. Each windmill will be supported by three such foundation pillars. Andree Krüger explaines: "We're using a special device - a large vibrating machine. Yesterday, we used this device to pre-install the pillar to a depth of 21 meters. Today, we'll pound it in the rest of the way." Then the hammer is installed. The one hundred tonne colossus pounds each pile 40 meters into the sea floor --penetrating silt and rock-hard sand. Meanwhile, at Cuxhaven harbor, they are preparing to transport the platform that will be put on top of the foundation piles as the base of the windmill tower itself. The platform weighs 490 tonnes -- about as much as two Airbus A 380s! It takes a day to load it onto a ship. It's not until after nightfall that the vessel sets off for the offshore construction site. It arrives the next morning. In the meantime, the foundation piles have been driven deep into the sea floor. Now the big moment -- mounting the platform onto the foundation piles... Towards evening, the platform is finally suspended above the piles. Bingo! ... a few more tense minutes until the platform is connected to the foundations. At last, it's time to celebrate --for tonight, at least. As soon as the sun rises in the morning, it's back to work. There isn't much time to play with. The windmill is due to be hooked up to the grid within a few days.
DW-World | September 23, 2008
