An offshore wind farm.
Offshore wind farms are power plants built on bodies of water. These farms can be built on lakes, coastal waterways and oceans. The cost of construction increases the further the wind turbines are located from the coast. This increase in expenses is based on the distance the electricity needs to travel back to earth and the cost of building the base on which the wind turbines will be located.
As of 2009, the Horns Rev 2 wind farm in Denmark is the largest offshore farm in the world. It is located in Horns Reef, which is a shallow area of the North Sea. The combined power output of the two offshore wind farms located at Horns Rev 2 is around 369 megawatts (MW) per year. That’s enough energy to power 350,000 homes in Denmark. The UK generates the most wind power, with Denmark falling in second place.
Currently, offshore wind farms are mostly built in shallow water. Deeper waters are often characterized by high wave heights, which incurs additional construction costs. Models are being developed to lower the cost of offshore placement of these power stations even further offshore, where wind speed and consistency can increase production. These models include floating offshore wind farms.
As of January 2009, there were 28 offshore wind farms currently supplying electricity to eight countries. Seventeen more offshore wind farms were under construction, with completion dates scheduled between 2009 and 2012. In addition, there are 35 proposed wind farms to be built in the United States, Germany and China. The UK is responsible for 15 of the wind farms under construction or being proposed.
While Denmark’s Horns Rev 2 wind farm is the largest, with an output of 369 MW, a proposed wind farm in the Great Lakes area between the US and Canada would provide more than 10 times that amount. The first estimates put the potential electricity production for the Wasatch Wind Farm, a combined effort between the two countries, at 4400 MW. The company set to build the Wasatch Wind Farm, Trillium Power Wind Corporation, is currently working on three projects – the Superior Array, Great Lakes Array and Trillium Power Wind 2 offshore wind farms – among others.
Offshore wind farms take approximately six months to build and can last up to 20 years before being decommissioned. The time spent in the construction and decommissioning steps can pose a threat to the surrounding marine life. Marine conservation groups and wind energy companies are researching these effects and any potential changes that could lessen the environmental impact on marine life.