Wind turbines (UK domestic)
Encyclopedia
Small wind turbines intended for installation on an individual home have been on the market in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 for many years, but their popularity and public awareness is now increasing substantially.

Claims about their efficiency and productivity are under some debate due to the disparity of manufacturer's forecasts with case study results. The prime problem is that they are routinely being installed in areas with wind speed
Wind speed
Wind speed, or wind velocity, is a fundamental atmospheric rate.Wind speed affects weather forecasting, aircraft and maritime operations, construction projects, growth and metabolism rate of many plant species, and countless other implications....

s much too low to realise a useful level of energy
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...

 return. Wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...

-powered electricity generation
Electricity generation
Electricity generation is the process of generating electric energy from other forms of energy.The fundamental principles of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday...

 requires wind speeds above those found in the great majority of inhabited areas.

Planning permission

The regulations are expected to change in 2007 with wind turbines coming under the same permitted development
Permitted development
Permitted development is an aspect of town and country planning in the United Kingdom which allows people to undertake minor development under a deemed grant of planning permission, therefore removing the need to submit a planning application...

 rights as satellite dishes. A consultation period on the proposed changes ended on June 27, 2007.

Wind-speed

Many of the manufacturer's examples rely on assumptions about average wind speed which, in practice, is very variable. This is particularly important because power available from the wind is proportional to the cube of the wind-speed (the kinetic energy of a moving mass, air in this case, is proportional to the square of the speed, the power is the rate of delivery of this energy which is also dependant on the speed the wind is passing the turbine, hence the cubic relation). Consequently halving the wind speed reduces input power by a factor of eight, not by a half.

The change in output power is greater than this factor of 8, since even the best wind generators only begin to generate at a 4 meters per second. They are also restricted by high winds, wind at more than 25 metres per second will stop the turbine Thus wind speed in the locality is a critical factor.

It is therefore important that local average wind-speed is determined, and that buildings or other natural features that may disrupt the smooth flow of the wind are taken into account before purchasing. Most built up areas in Britain do not have sufficient wind speed for productive generation. The presence of trees and buildings in built-up areas make wind speeds even lower and create turbulence. Often, only more exposed rural locations may be suitable. Vertical axis wind turbines are less prone to turbulence and start producing at lower wind speeds.

In unsuitable areas, one alternative suggested may be to form a cooperative, such as the Baywind Energy Co-operative
Baywind Energy Co-operative
Baywind Energy Co-operative was the first co-operative to own wind turbines in the United Kingdom.Baywind was modelled on the similar wind turbine cooperatives and other renewable energy co-operatives that are common in Scandinavia, and was founded as an Industrial and Provident Society in 1996. It...

, to provide a larger-scale turbine to serve the local community. While there are few of these in the UK, they are common in other countries, notably Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

, where around 5% of the population are involved in such schemes. However it is generally better to place turbines in more suitable high wind speed areas, which are not generally centres of population.

Example costs

The following example costs are taken from manufacturer's literature. See the section above regarding the importance of wind-speed in these examples.

Refer to bettergeneration.co.uk for an index of domestic turbines.

Windsave turbine WS1000 (1 kW)
Claimed average output: 500 kWh per year
Note: 2 years warranty, expected working life of 10 years. Windsave went out of business on 4th September 2009
Materials: £1,600
Installation: Included
Tax: Included
30% Clear Skies Grant: £500
Total Costs: £1,100


Swift turbine (1.5 kW)
Claimed average output: 2000 kWh per year
Materials: £3,500
Installation: £1,950
Tax: £272
30% Clear Skies Grant: £1,700
Total Costs: £4,022


Stealthgen by Eclectic Energy (0.4 kW)
Claimed output: 660 kWh per year
Materials: £875
Installation: not included, estimate £800
Tax: Included
Grant: not currently available
Total costs: £1,675

See also

  • Wind turbine
    Wind turbine
    A wind turbine is a device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator or wind charger. If the mechanical energy is used to drive machinery, such as for grinding grain or...

  • Wind power in the United Kingdom
    Wind power in the United Kingdom
    By mid-2011, the installed capacity of wind power in the United Kingdom was over 5.7 gigawatts and the UK is ranked as the world’s eighth largest producer of wind power. Wind power is expected to continue growing in the UK for the foreseeable future, RenewableUK estimates that more than...

  • Energy policy of the United Kingdom
    Energy policy of the United Kingdom
    The current energy policy of the United Kingdom is set out in the Energy White Paper of May 2007 and Low Carbon Transition Plan of July 2009, building on previous work including the 2003 Energy White Paper and the Energy Review Report in 2006...

  • Energy use and conservation in the United Kingdom
    Energy use and conservation in the United Kingdom
    Energy use in the United Kingdom stood at 3,894.6 kilogrammes of oil equivalent per capita in 2005 compared to a world average of 1,778.0. In 2008, total energy consumed was 9.85 exajoules - around 2% of the estimated 474 EJ worldwide total...

  • Microgeneration
    Microgeneration
    Microgeneration is the small-scale generation of heat and power by individuals, small businesses and communities to meet their own needs, as alternatives or supplements to traditional centralized grid-connected power...

  • Low Carbon Buildings Programme
  • Domestic Wind Turbine installation videos
  • Domestic Wind Turbines - a blog created to inform potential buyers of small turbines
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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