Wind Turbines
Your Questions About Wind Turbines
- Is my site windy enough?
Wind speed varies with time, from nothing on calm days to occasional violent gusts. If the wind speed at a site is recorded over a year, it will be seen to vary about a mean wind speed value. This is the annual mean wind speed (AMWS) and is an indication of how much wind energy is available. In the UK, AMWS could be as low as 4 m/s (9.0 mph) for an inland site to around 8 m/s (13 mph) or higher on the most exposed sites.
In general, you need an AMWS of at least 4 m/s to be able to generate a reasonable amount of energy, and ideally more than 4.5 m/s.
You can get a reasonable estimate of the ‘windiness’ of a site from its location. The UK Government funded a database (NOABL) which gives an estimate of Annual Mean Wind Speeds (AMWS) in meters per second (m/s) for each 1km square all over the British Isles for a height of 10m.
You can also use our wind speed checker.
- How high should the wind turbine tower be?
Our standard towers are 9, 12, 13, 15 and 18m metres high. In general, the higher the tower, the higher the average wind speed that the turbine will experience, but it may not always be the case in normal UK conditions, that a taller tower will generate sufficient extra energy to justify it's additional cost, unless there are local obstacles to be avoided. Our initial site survey will give you estimates of the expected energy output from the turbines at various tower heights, and allow you to make an informed decision.
- How much space do I need for a wind turbine?
Ideally, the turbine should be sited as far away as possible from buildings or trees, which may block the wind and cause turbulence. As a guide, the wind generator should be about twice the height of obstructions in front of it (for at least the prevailing wind direction).
- Is a wind turbine noisy?
The wind generator will also create a small amount of noise, so planning authorities will not let you site one too close to your neighbours. The actual distance however will depend upon a number of factors, including the local terrain, trees and the background noise in the area. As a guideline however, the larger turbines should be sited at least 75m - 100m from your nearest neighbour and 50m from your own house. Smaller turbines may be sited as near as 50m to a neighbours, but consideration will always need to be given to the potential visual impact on neighbours.
- Can I mount my turbine on the roof of one of my buildings?
If you are going to mount a turbine on a roof then you have to consider that there will be increased turbulence resulting in higher stresses on the turbine and lower energy capture for any given wind speed. There will be more people living and working near the turbine so increased margins of safety need to be applied, and lower noise generated. And the average wind speed in a town or city environment will be a lot less than the national wind speed database (NOABL) indicates, and this will significantly reduce the annual energy capture. We do not recommend a small wind generator in an urban environment
- Do I need planning permission?
It is essential in England and Wales to get planning permission to install a small wind turbine, we will help you with this process and provide you with all the supporting information you need.