Wind Turbines

What is a wind turbine?

A wind turbine is a rotating machine which converts the kinetic energy of wind into mechanical energy. The wind catches the large blades of the wind turbine, forcing them to turn, thus driving a turbine which generates electricity. The stronger the wind, the more electricity produced.

If the mechanical energy is used directly by machinery, such as a pump or grinding stones, the machine is usually called a windmill.

If the mechanical energy is instead converted to electricity, the machine is called a wind generator, wind turbine, wind power unit (WPU), wind energy converter (WEC), or aerogenerator.

In recent years, large scale wind farms have become a common site on the horizon. They now contribute almost 2% of all our electricity (and rising). However, the construction of wind farms is not universally welcomed due to their visual impact and other effects on the environment. Loathed by many they are said to cause illnesses in those subjected to their noise.

Wind energy provides an extremely green form of electricity. Unlike fossil fuels it is plentiful, renewable, widely distributed, clean, and produces no greenhouse gas emissions.

In domestic situations, it is often the option of choice in areas where there is no connection to the national grid.

Small systems are known as "microwind" turbines. A typical domestic system would be 2.5 - 6 kilowatts, depending on the location and size of the home.

The turbines are often mast mounted, free standing systems which are erected in a suitably exposed position. Smaller turbines (1kW to 2kW) can be roof mounted.

In non-grid locations, the electricity produced requires battery storage and an inverter to convert the DC electricity generated to AC. As wind speed cannot be guaranteed, it is better that the wind turbine is used in conjunction with another energy source, generally a diesel generator, to provide electricity when there is little wind.

In locations where there is a grid connection, the electricity does not need to be stored in batteries. Instead, anything that is not used immediately is sent to the grid and bought by the local utility company leaving the users account in credit. Any electricity used from the grid is then free until that credit is gone.

Wind power is proportional to the cube of the wind's speed, so small increases in speed result in large increases in the energy that can be obtained. Generally a wind turbine is not recommended unless the average wind speed in your area is over 5m/s. It is worthwhile getting a full site assessment as if the wind speed isn't going to be good enough you'll be wasting your money.

Wind speed increases with height so the higher the turbine is placed the better. The ideal location would be high on a mast or tower on top of a hill without obstructions such as large trees, houses or other buildings in the way.

Once only of interest to a small minority, green is the new black as far as self-building is concerned.

With the effects of global warming becoming increasingly apparent, more and more people are seeking greener ways to provide the energy needed to run a home.

Whether it's solar panels, heat pumps, high specification glazing or eco-friendly wool insulation in the loft space, there is little doubt that it is self-builders who are setting the standards for a greener future for the building industry and the way we live our lives.

Underfloor heating for example, has been available for years but, by and large, the self build market has been the industry's bread and butter - with large scale property developers still opting for standard, less efficient radiators.

But it's not all about saving the planet. Incorporating green ideas into a home can lead to reduced running costs and save you money in the medium to long term too. And when you come to sell your home in the future, you can guarantee that the greener it is the more attractive it will be to prospective buyers.

There is a greater sense of purpose from the government to promote green alternatives too with a stick and carrot approach in place.

Building regulations now demand far better energy efficiency while government grants are available for loft insulation right through to solar panels, heat pumps, wind turbines and other microgeneration technologies.

Self-builders are leading the way as far as greener homes are concerned and greenselfbuild.co.uk will be with you every step of the way towards a greener future for you, your family and the wider community.