Denmark leads the world in the use of wind energy to generate electricity, particularly in offshore wind farms, and has the world's leading wind turbine manufacturing industry. In 2007 wind generated nearly 20% of Denmark's electricity use, by far the largest share among all nations. Denmark's pioneering efforts result from a combination of favorable offshore wind conditions, government subsidies, strong public support, and technological improvements that have lowered the cost of wind-generated electricity.

The wind resource

Denmark has relatively modest onshore average wind speeds in the range of 4.9 to 5.6 meters per second measured at 10 meters height. Onshore wind resources are highest in the Western part of the country, and on the Eastern islands with coastlines facing South or West. The country has very large offshore wind resources, and large areas of sea territory with a shallow water depth of 5 to 15 meters where siting is most feasible. These sites offer higher wind speeds, in the range of roughly 8.5 to 9 meters per second at 50 meters height. Government support of wind development since 2001 has focused primarily on the offshore region.

Installed capacity

Denmark had 3,125 MW of wind power installed in 2007, placing it behind Germany, the U.S., Spain, India, and China—a large absolute quantity given its small size. Denmark was the pioneer in this field as it built the first offshore wind farm in the world in Vindeby in 1991. It has now eight operating wind farms, including the biggest offshore farm one in the world, located at Horns Rev in the North sea, composed of eighty 2 MW turbines that generate enough power to meet the demand of 150, 000 Danish homes. Wind conditions are exceptional in this area: rated production is between 40 and 50% of the year. Horns Rev is sited 14-20 km into the North Sea, west of Blåvands Huk, and was the initial phase of a large-scale Danish effort to produce electricity from offshore wind turbines.  The water depth is in the range of 6 to 14 meters. The Horns Rev offshore wind Farm is 60 percent owned by the Vattenfall Group and 40 percent owned by DONG Energy.

The wind turbines are interconnected in a 33 kilovolt cable system. The power generated passes to a transformer platform on the fringe of the offshore wind farm. Here the voltage is transformed up to 150 kV before the electricity is taken to the shore through a 21 km long submarine cable to Hvidbjerg Strand. The submarine cable, manufactured in Norway, is the first plastic-insulated 150 kV cable in the world. With a diameter of 19.2 cm, it is also the thickest submarine cable ever made.

Two upcoming farms of a capacity of 200 MW each, Horns Rev II and Rødsand, expected to be commissioned 2009/2010, will generate enough energy to power from 350,000 to 400,000 Danish homes.

The government also requires that distribution companies provide for the flow of wind energy into the grid.  According to the Executive Order on Grid Connection of Wind Turbines of 1996, local power distribution companies are obliged to provide grid connection facilities at any site which in municipal planning has been set aside for the development of at least 1.5 MW of wind power.

Government support

The rapid deployment of wind energy has been made possible by generous financial incentives provided by the federal government that encourage renewable energy (this is true for all nations with strong wind energy programs). Subsidies for wind turbines depend on, (1) when the turbine is connected to the grid, and (2) its age. Basically, wind plant owners are guaranteed a price for the electricity they generate that will encourage development of more wind power. This subsidy is essentially a fixed price system, with an environmental premium per kWh in addition to the market electricity price. The premium is financed as an addition to the electricity price per kWh, shared equally among all electricity consumers in relation to their electricity use.

For example, wind turbines connected to the grid after January 2005 are eligible for a premium of 10 øre/kWh until the turbine is 20 years old (the øre is the one-hundredth subdivision of the  Danish krone). By way of comparison the average price paid by consumers in 2006 was 24.4 ør/kwh. 

Wind turbine manufacturing

Danish manufacturers are leaders in the global wind industry. Denmark hosts five of the world's ten largest wind turbine suppliers: NEG-Micon, Vestas Wind Systems, Bonus Energy, Nordex, and Wind World. The first three companies account for more than 50 per cent of world production of wind turbines measured in MW.

With a 23 per cent market share in 2007, and 35,500 wind turbines installed, Vestas is the world's leading supplier of wind power technology.  From a staff of approximately 60 in 1987, Vestas now employs 15,000 people worldwide and has installed turbines in 63 countries.

Ownership

Another force behind Denmarks' remarkable embrace of wind energy is its system of ownership.  Danish utilities are mostly nonprofit cooperatives owned by the electricity consumers in each area, although some municipalities in the larger cities are the owners of distribution companies. Ownership of distribution companies cannot be traded, but is implicitly held by the property owners who consume electricity. Governing boards are elected locally. The distribution companies jointly own transmission and generating companies. The many local power companies operate an internal sharing arrangement for their wind energy deployment, which means that they effectively pool their wind energy investments to ensure that wind energy is deployed primarily in good, windy areas.

Public support

Wind energy has flourished in Denmakr in large part because it has strong public support. The wind energy market grew out of a popular interest in alternative energy technologies, partly in opposition to the use of nuclear power, partly as a result of the energy supply crisis in the late 1970s, when oil prices skyrocketed due to OPEC action and political and military unrest in the Middle East. More recently, public concern about climate change has lead to the adoption of policies and technolgies that reduce emissions of carbon dioxide, especially wind energy.

 Sources

• Wind Energy Department, Risø National Laboratory for Sustainable Energy, Technical University of Denmark, Accessed 15 September 2008.
• Danish Wind Energy Authority, Accessed 15 September 2008.
• Danish Energy Authority, Accessed 15 September 2008.