Renewables: Wind Turbines for Home Installation

With the potential of UK wind energy being the greatest in Europe, the Energy Saving Trust suggests that this figure is 40%, the increase in installed wind turbines has greatly increased in recent years. It is expected that installed wind energy potential will double every three years, and domestic wind energy is becoming increasingly more affordable. But at the moment wind power accounts for a fraction of our electricity needs.

If you do not wish to install a wind turbine you could support wind energy through your current electricity supplier some of which offer for free green energy tariffs.

The majority of wind turbines generate direct current, for systems on the grid this can easily be installed to the current electricity supply with an inverter and controller. For off-grid systems these also require a battery. Excess energy to requirements can be sold to your local electricity company, however rates vary (from 1p/kWh - 6p/kWh) and are normally dependant on time.

There are two types of wind turbines:

• Mast mounted - which are free standing and located near the building(s) that will be using the electricity.
• Roof mounted - which can be installed on house roofs and other buildings.

Wind energy is a renewable source of clean energy, a 2.5Kw system can save 1-2 tonnes of C02 and £150 - £250 per year. A 6kW system can save 2.5 - 5 tonnes C02 and £250 - £450 per year. Larger systems in the region of 2.5kW to 6kW would cost between £11,000 - £25,000 installed. These costs are inclusive of the turbine, mast, inverters, battery storage (if required) and installation; however it's important to remember that costs always vary depending on location and the size and type of system.

Turbines can have a life of up to 20 years but require service checks every few years to ensure they work efficiently. For battery storage systems, typical battery life is around 6-10 years, depending on the type, so batteries may have to be replaced at some point in the system's life.

Individual turbines vary in size and power output from a few hundred watts to two or three megawatts (as a guide, a typical domestic system would be 1 - 6 kilowatts). Uses range from very small turbines supplying energy for battery charging systems (e.g. on boats or in homes), to turbines on wind farms supplying electricity to the grid.

You should consider the following issues if you're thinking about small scale wind. An accredited installer will be able to provide more detailed advice.

• Wind speed increases with height so it's best to have the turbine high on a mast or tower.
• Generally speaking the ideal site is a smooth top hill with a flat, clear exposure, free from excessive turbulence and obstructions such as large trees, houses or other buildings.
• Small scale wind power is particularly suitable for remote off grid locations where conventional methods of supply are expensive or impractical.

Small-scale building-integrated wind turbines suitable for urban locations are also available to install in homes and other buildings.

Please note that the electricity generated at any one time by a wind turbine is highly dependent on the speed and direction of the wind. The windspeed itself is dependent on a number of factors, such as location within the UK, height of the turbine above ground level and nearby obstructions. Ideally, you should undertake a professional assessment of the local windspeed for a full year at the exact location where you plan to install a turbine before proceeding. In practice, this may be difficult, expensive and time consuming to undertake. Therefore we recommend that, if you are considering a domestic building mounted installation and electricity generation is your main motivation, then you only consider a wind turbine under the following circumstances:

• The local annual average windspeed is 6 m/s or more. An approximate figure for your location can be checked on the DTI website
• There are no significant nearby obstacles such as buildings, trees or hills that are likely to reduce the windspeed or increase turbulence

If you are in any doubt, please consult a suitably qualified professional.
Planning issues such as visual impact, noise and conservation issues also have to be considered. System installation normally requires permission from the local authority, so it's important to always check with your local authority about planning issues before you have a system installed.

If you are interested in installing a wind turbine, typical installation cost for a domestic system is £2,000 - £4,000 per kW, however grants are available from the low carbon buildings programme (funded by the Department of Trade and Industry, DTI). To be eligible for a grant you will need to use a certified installer and products. The low carbon buildings programme offers a maximum of £2 500 or 50% of the relevant eligible costs, whichever is the lower for solar PV systems.

Related Links

Low Carbon Buildings Programme
Department of Trade and Industry
Certified Installers
Certified Products