Renewable Energy Solar Panels and Wind Turbines
MEETING YOUR NEEDS WITH RENEWABLE ENERGY
Advice on Turbine Siting
The location of a wind turbine is fundamental to its performance, but there are other factors that should be taken into account when deciding the best position for a wind turbine.
The comfort and safety of the customer and those who come into contact with the installed turbine, is of great importance and must be considered.
There is currently no accepted industry guidance or recommended practice on siting a wind turbine. Photon Energy has been actively encouraging the industry to develop these guidelines, but we have developed our own guidance in the interim. We will of course adhere to any industry accepted guidance as soon as this is available.
Location
The ideal location for a wind turbine is on the top of a smooth, rounded and exposed hill with no obstructions to cause disruption to the wind flow. However, in reality such a site is rarely the case.
In practice the most important factor to consider is the wind speed of the site. With the power being proportional to the wind speed cubed, a small increase in wind speed can have a large effect on the power output. The wind speed can be maximised by using higher towers and by siting the turbine away from obstructions.
Spacing Requirements
Small turbines are usually winched into position using a tirfor winch. The turbine is bolted to the foundations and laid down. The winch is connected to the winch point, as shown in the diagram below. This means that a turbine on a 15m mast usually needs 30 metres of space to allow it to be lowered for servicing. Some turbines can be raised and lowered with a hydraulic RAM so a winch point is not needed.
Larger wind turbines can be lifted into position using a crane but there needs to be sufficient access for the crane, and also for a scissor lift for future maintenance.
Multiple Turbine Installations
When more than one turbine is installed, they should be spaced a minimum of 3 rotor diameters apart.
Noise
Wind turbines are not silent and can often be heard above the background noise. We recommend smaller turbines should be at least 50 metres from any dwelling or offices, and larger turbines at least 500m.
Shadow Flicker
Shadow flicker may occur under when the sun passes behind the rotors of a wind turbine and casts a shadow over neighbouring properties. As the blades rotate, the shadow flicks on and off, an effect known as shadow flicker. The effect occurs inside buildings, where the flicker appears through a window opening. The likelihood and duration of the effect depends upon:
- Direction of the property relative to the turbine
- Distance from turbine
- Turbine height and rotor diameter
- Time of year and day
- Weather conditions (i.e. cloudy days reduce the likelihood of effects occurring)
In the UK, properties only within 130 degrees either side of north, relative to the turbines, can be affected, as turbines do not cast long shadows on their southern side.
The further the distance from the wind turbine, the less pronounced the effect becomes. Flicker effects only occur within ten rotor diameters of a turbine.
Safety Zones
Although many precautions can be taken to ensure the safety of the customer (using approved products, high quality installation by an approved installer and regular maintenance of the turbine) there is a possibility, however small, that mechanical failure can lead to part of the turbine falling to the floor. For this reason we recommend three levels of safety zone.
|
Zone |
Zone dimensions |
Guidance |
1 |
Mast height |
Exclusion zone, marked and protected using low fence where appropriate in public places |
2 |
Mast height plus blade length |
Low occupancy zone, maximum 4 person hours per day, no benches or shelters to encourage congregation. |
| 3 | 50 metres |
Average occupancy zone, typical occupation of 240 person hours per day |
