In the UK we have 40% of Europe's total wind energy. But it's still largely untapped and only 0.5% of our electricity requirements are currently generated by wind power. Wind power is a reasonably simple technology that can make a difference to their home's energy consumption, particularly where there is a suitable location for a free-standing mast.
Wind turbines use the wind to rotate aerodynamic blades that turn a rotor which creates electricity. This may supply energy for a battery, or supply electricity to the grid. Wind turbines can be free standing, mounted on a mast and located near the building(s) that will be using the electricity, or roof mounted micro-turbines, installed on the house roof.
What are the costs and savings?
Roof mounted micro-turbines cost from £1500, and the savings they can be expected to generate have not yet been monitored or verified. The Energy Saving Trust is currently collecting data to calculate typical energy and carbon savings. Larger mast-mounted systems in the region of 2.5kW to 6kW would cost between £15,000 and £25,000 installed, depending on location and the size and type of system.
Important points
The electricity generated depends on the wind speed and direction. It will probably not be effective to install a domestic wind turbine unless the local annual average windspeed is at least 6 metre per second, and there are no significant nearby obstacles such as buildings, trees or hills that are likely to reduce the windspeed or increase turbulence
- Consult an installer accredited with the Microgeneration Certification Scheme to provide more detailed advice about your individual circumstances.
- Turbines can have a life of up to 20 years but require service checks every few years to ensure they work efficiently.
- Consult the local authority about planning permission
- Small scale wind power is particularly suitable for remote off grid locations where conventional methods of supply are expensive or impractical and the wind speed and direction are suitable.
- Micro-wind turbines mounted on roofs in urban locations do not provide much power and are probably the least effective renewable energy measure.
Location, Location, Location - a field trial
The Energy Saving Trust undertook a field trial of domestic wind turbines in 2007, monitoring the performance of 57 turbines installed at various UK locations. Called Location, Location, Location, its key findings were:
- Most building-mounted turbines in urban or semi-urban locations had inadequate wind speeds and performed poorly.
- Free-standing turbines in suitable sites performed well.
- Scotland contained the best locations due to higher wind speeds.
- Potential customers should ensure that products conform to the standards developed by the Microgeneration Certification Scheme.
- The government's windspeed database - called the Numerical Objective Analysis Boundary Layer (NOABL) - which was used to estimate local windspeeds, was found to significantly overestimate wind speeds. MCS accredited suppliers should use an adjustment, to give a more accurate value. The Wind Yield Estimation Tool provided by the Carbon Trust was found to be a more accurate prediction method.
The report is available to download from the EST website, by clicking here. A windspeed prediction tool is also available from the same website.