Ref: Renewable.Energy.Focus.com, 2009/11/19

The facility, alpha ventus, was built by EWE, E.ON and Vattenfall in the consortium DOTI (Deutsche Offshore-Testfeld- und Infrastruktur Gesellschaft GmbH) at a cost of €250 million(~120億NTD). All 12 wind turbine units were installed in less than 7 months, and 6 of the wind turbines are already being test-run and have generated 13 million kWh of wind power.

The wind farm, sited 45 km north of Borkum island in the North Sea, is the world's first offshore wind park that uses a dozen 5 MW wind turbines. At full operation, alpha ventus will generate sufficient electricity for 50,000 homes.

“With the building of alpha ventus, our three companies have shown that offshore wind energy is technically feasible in Germany, even under considerably difficult conditions,” says project director Wilfried Hube of EWE. “The construction of 12 5 MW wind turbines 45 km from the shore in waters 30 m deep, is a true piece of pioneering achievement and is the first of its kind worldwide.”

The offshore wind farm project relied on the experience of other offshore installations, but the harsh conditions of the North Sea provided a true test for the feasibility of offshore wind power in Germany and is a remarkable logistical achievement, the consortium notes. Initial difficulties with construction vessels in 2008 prompted them to select more suitable equipment this year.

“We learned that the construction process and the employed logistics must be very well attuned with one another in order to be build effectively,” adds Oliver Funk of Vattenfall. “In this regard, we faced a very steep learning curve.”

During peak construction this summer, 350 people and 25 ships were simultaneously at work on the offshore wind farm site. The vessels included three new jack-up barges that arrived at alpha ventus almost directly from their shipyard, as well as Thialf, the largest crane ship in the world that installed the jacket foundations for the REpower wind turbines in 6 days.

The construction of alpha ventus was more complex than other offshore wind farms, which have been built outside Germany. Two types of German-manufactured wind turbines were built on two different types of foundations using various construction concepts and “construction has provided us with valuable information for future offshore projects,” says Ralf Lamsbach of E.ON.

The six Areva Multibrid M5000 wind turbines stand on tripods, and feature a rotor diameter of 116 m and hub height of 90 m. They are 178 m total height above the seabed, and weigh 309 t with rotor and hub. So-called ‘jacket’ foundations are used for the REpower wind turbines, which have a rotor diameter of 126 m, hub height of 92 m, 185 m total height above seabed and weigh 410 t.

The second lot of 6 wind turbines will come online by the end of the year. One hundred technicians passed ’helicopter abseil-training’ in Cuxhaven recently, so they can reach the wind turbines from the air if the sea route becomes inaccessible due to inclement weather or high swells.

An internet webcam has been stationed on the FINO1 construction platform showing the progress on the building site, and DOTI is ready to transmit the power to shore. An underwater cable, installed last year by transpower GmbH (formerly E.ON Netz), connects the offshore transformer station to the German power grid.

For a short time last Sunday (8 November), blustery winds in Spain allowed wind turbines to supply 53.7% of total power demand across the country. The output was equivalent to 11 nuclear reactors, and was 10.7% higher than the previous record of wind power output set last year.

The peak occurred between 03:00 and 08:30 a.m. (local time) on Sunday, when national demand ranges from 21,700 to 19,700 MW. On that afternoon at 14:30 p.m., the maximum of simultaneous wind energy production of 11,546 MW was set, 343 MW more than the 11,202 MW achieved on 5 March when wind turbines accounted for 29% of national demand.

In the first 9 days of this month, wind generated 1,770,486 MWh in Spain, ahead of the 1,369,955 MWh from combined cycle facilities and the 1,223,350 MWh from nuclear.

By 2020, Spain is expected to double its wind capacity from the current 16,000 MW to 45,000 MW. The World Wind Energy Association says Spain’s installed wind power capacity in January was 16,740 MW, in third place behind the USA (25,170 MW) and Germany (23,903 MW).

The global wind capacity was 121,188 MW earlier this year, of which 27,261 MW were added in 2008 and generate 260 TWh per year. The wind energy sector has created 440,000 jobs, the claims WWEA, and represents annual revenue of €40 billion.

Last year, Spain's wind farms covered 11.5% of power demand, avoided the emission of 20 Mt of carbon and the need to import €1,200 million of fossil fuels.