Energy? The answer is blowing in the wind
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Dong Energy wind farm off Copenhagen harbour
Can the solution to climate change really lie in the hands of technology? We decided to find out during a boat ride to the Middlegrunden offshore wind farm near Copenhagen harbour, one of the largest such farms ever built.
Located near the bridge that connects Denmark to Sweden, these massive turbines are an impressive sight, with huge blades that have a 76 m rotor diameter set along a 3.4 km arc across the bay. They revolve slowly in the cold wind that blows in from the Baltic Sea, making a low whooshing sound.
There are twenty wind turbines in total in this particular wind farm set up by the Dong Energy group, each producing two megawatts of energy (enough to power 40,000 households). Turbine technology has been refined over the years and prices have also gone down – almost 85-90% since 1985, making wind energy comparable with other power sources in Denmark, or even cheaper.
The Danes are in fact one of the global leaders in this technology and Dong Energy is now building wind farms in Poland and the UK as well. Founded in 2006 as a conglomerate of six Danish energy companies, Dong has built almost half of all the offshore wind farms in operation in the world today.
More than 20 per cent of the total energy in Denmark comes from wind power – the rest is from gas- and coal-fired plants. Dong sees growth in the wind energy market in Europe, the US and Asia, and is eager to export its technology and willing to host programmes in capacity building and training.
“People are waiting for the price to come down; they are ready for energy security and want to tackle climate change”, said one of their representatives on the boat. “Can you hear the sound of the wind turbines? It is the sound of energy, of money!” The wind turbines have an efficiency of 93% so are able to produce energy even if the winds are weak.
Before the project was installed in 2000, Dong Energy says an extensive Environmental Impact Assessment was conducted whose results were shared with the public. The company says it ensured that there would be no heavy metal contamination from the turbines which were installed on the concrete foundation on the sea bed.
The turbines are equipped with modified corrosion protection, internal climate control, high-grade external paint and built-in service cranes. They also checked for noise disturbance (they are located 10 km from the shore) and researched to see whether the flora and fauna could be affected.
The EIA was published by the Copenhagen Energy group and the Middelgrunden Wind Turbine Co-operative in May 1999. The co-operative (which has 8,000 members) in fact owns 10 of the turbines. It has been awarded the European Solar Prize 2000, the Energy Globe Award 2001 and the Green Apple Award 2001.
These are not Dong’s biggest wind turbines, though – it is testing rotors 120 m in diameter, which are due to be installed in 2011 in offshore wind farms in Northern Europe, after extensive testing. With such large rotors, 3.6 megawatts of energy can be produced.
