Energy / Examples /
English Heritage Wind Energy and the Historic Environment. English Heritage WIND TURBINE TECHNOLOGY By converting wind energy into electricity, wind turbines reduce the environmental impact of power generation.Wind energy is currently the most developed of a number of renewable energy technologies, with more than 1,000 wind turbines already operating across the UK, producing around one quarter of one percent of the country’s energy. Wind turbines can be deployed individually, to power a single site or installation, but are most commonly grouped together as ‘wind farms’ to provide power to the national grid.The energy output from turbines has increased dramatically over the past decade from 200 KW to 3 MW and with 5 MW turbines now under evaluation.Their greater energy yield means that the number of turbines needed to produce a given amount of energy has been reduced by at least a factor of five. Over the same period, however, the tower height and rotor diameter of turbines has doubled. Large modern wind turbines have rotor diameters ranging up to 65 metres.Towers range from 25 to 80 metres in height and, when a blade is vertical, some of the larger modern wind turbines can reach a total height in excess of 100 metres. Larger-scale wind energy developments are also becoming increasingly common as turbine ratings increase. In 2003, around a third of completed developments were above the 50MW threshold, and wind farms may now include up to 24 turbines and cover a total area of around one square kilometre. As technical advances increase its cost effectiveness, offshore wind generation is beginning to play an increasingly important role in achieving renewable energy targets. By 2006, the installation rate for offshore generation is predicted to overtake that onshore. Currently, fifteen wind energy developments are planned in three strategic sea areas identified by government off the UK’s eastern and western coasts. Offshore wind farms are generally large installations. Current turbine hub heights range from 40 to 100 metres and rotor diameters from 44 to 110 metres, with turbines likely to increase further in size and capacity. Although this increase in scale could intensify the visual impact of offshore installations when seen from the land, parallel improvements in technology which allow them to be located further from the shore may tend to mitigate this effect.A major expansion of offshore capacity is, however, likely to require a significant strengthening of the national grid at the coast where it is currently poorly developed. http://www.helm.org.uk/server.php?show=nav.9257
Denmark Denmark is an excellent example of a European country, which has achieved a substantial growth in renewable energy infrastructure over the last decade. This should be seen in context of steady economic growth and relatively low unemployment, whilst maintaining stable energy consumption levels through energy efficiency measures and large-scale developments in cogeneration of heat and electricity. Denmark demonstrates the success of "soft" energy solutions, a success that has contributed to the economic development of the country in a dynamic and sustainable manner.
The development has not been achieved without setbacks: development of new sectors of the economy such as renewable energy cannot be done without failures and need for improvements in technology. Many of the plants now in operation have been upgraded over a number of years, and many lessons have been learned. Another recent problem is cut back in government support for renewable energy that has severely reduced new installations. This is purely a political decision by the present Danish government.
There are almost 5000 wind turbines in operation in Denmark, widely distributed throughout the country… wind turbines with capacities from 300 kW to 1300 kW. Smaller turbines (5-25 kW and 50 -300 kW) as well as larger turbines (up to 2 MW) are found on land.
Denmark.dk: Official website - Denmark - Energy: an Overview
Every year, renewable energy accounts for an increasing part of the total energy consumption. In 1980 it was 3%, in 1990 6% and in 2000 more than 11%. In 2000, biomass supplied 40% of the renewable energy production, waste 34% and wind power 18%.
One of the main political objectives in the energy area in the 1990s was to promote the use of renewable energy. Denmark has a long tradition of exploiting wind power. Research and development of new kinds of wind turbines from the late 1970s, combined with favourable government grants towards wind power production, have created a Danish success story. In 2001, about 18% of Danish electricity consumption was supplied by wind power as opposed to 2% in 1990. Concurrently, Danish wind turbines have become a major export commodity with currency earnings of approximately DKK 12 billion in 2001. www.denmark.dk
New Energy 2003 issue 2 describes how, “in what was once the cradle of wind power, the …government is endangering further growth with market-oriented energy policy ” Many of the earlier wind turbines were individual structures or in small groups of three or five turbines and were social enterprises, commissioned and owned by local people who agreed to purchase the electricity before planning and other consents were sought, thus ensuring community support rather than disagreement and resistance to change. The presence of new structures in the flat and open landscapes of Jutland and the Danish Islands was a source of pride, ownership and visual acceptance. The success of Danish turbine manufacturers and considerations of economies of scale and efficiency of turbines moved production towards larger turbines and larger arrays, or wind farms, developed on a commercial basis. In valued and sensitive coastal and inland areas the visual impact of large towers and extensive wind farms reached and exceeded limits of acceptance. Off shore wind farms were created as an alternative. Recently the small and community operators received a significantly reduced subsidy for energy produced and many of the older turbines have now reached the 25 years of their normal lifespan. There are now government incentives to replace them with turbines that are three times as powerful. However, very few operators took up the offer and Denmark’s pioneering lead in wind generation has been overtaken by other states, notably Germany, where 3250 MW were added in 2002, more than the Danes had added in the previous 20m years. In 2003, 90 per cent of the turbine manufacture of Denmark was exported “We were hoping for more from the new government.I can’t imagine that many new plants will go up on land this year,” says Eltved,who repre- sents some 3,500 members – about 88% of Denmark’s private converter operators….The Danish Energy Agency sees things differently,of course.“Wind power will continue to grow signifi- cantly,” ....“We’re working hard to find more attractive sites to develop wind power,on land and offshore.” …Preben Maegaard,president of the World Wind Energy Association (WWEA) and managing director of the Folkecenter for Renewable Energy,based in Hurup Thy in northern Jutland,repeatedly tried to dissuade the industry association from this mistaken path. For Maegaard,the latest figures showing that the well-known manufacturers have cut themselves off from the domes- tic market come as no surprise. “It was inevitable,” he says. It also angers Maegaard that the economics ministry is scrapping the some 1,000 old mills dismantled in the repowering programme instead of exporting them to developing countries.“The Danish government is foregoing a chance to help wind energy to its feet in eastern Europe, for example…” http://www.wwindea.org/pdf/articles/NewEnergy_Denmark_2-2003.pdf