Installing a wind turbineWhich? wind turbine test

Which? tested a home wind turbine to see if it worked

The Windsave WS1000 was the first small wind turbine that uses wind power to generate a direct supply of electricity to be compatible with mains supplies. 

We bought one from B&Q and had it installed to see how much electricity wind power can provide to a typical, suburban home.

Update: since our test, wind turbine manufacturer Windsave went into administration in September 2009.

How does a home wind turbine work?

Electricity is generated when the blades are turned by the wind. The amount of electricity generated depends on the speed and consistency of the wind. The generated electricity is ‘plugged-in’ via a patented box (called an inverter) into your home’s standard mains supply.

The turbine doesn't operate as a stand-alone system, so you still need mains power – and it won't work if there's a power cut. Instead, the wind power supplements your normal electricity supply and potentially contributes towards reducing electricity bills.

Wind turbine planning permission

We recommend that you check with your local council about planning permission if you are considering installing a wind turbine.  Most councils encourage the installation of renewable energy products and systems, although there can be delays.

Our own planning permission took several months, although this lengthy delay can be attributed partly to the novelty of home wind turbines and council's inexperience in dealing with such applications.

Installing the Windsave WS1000 wind turbine

Our Windsave WS1000 turbine was installed by Windsave-approved installers to the side of our tester's house. 

Ideally, wind turbines should be positioned wherever there is maximum exposure to the wind, usually as high up as possible, facing the prevailing wind. Nearby trees and buildings can affect wind power performance. These rules to maximise performance were followed as far as possible with our wind turbine, mounted on our tester's suburban home.

Home wind turbines can usually only be installed by approved installers, who can provide further advice on the best position – find out more on installing a wind turbine.

Our wind turbine used more energy than it generated

How did the wind turbine perform?

In our case, not very well. A year after we bought the turbine, Windsave required us to sign a disclaimer saying that we understood that the wind turbine could only be recommended for areas with average annual wind speeds of five metres per second (m/s) or greater. Our tester's area has an average of 4.7 m/s – just below this.

During our 180 day trial, our wind turbine actually used more energy than it generated – a net loss of 9.4 kilowatt hours of power.

This was a big surprise – we suspected that performance would be poor when we saw the disclaimer, and we'd heard negative publicity concerning wind turbines, but we didn't expect that our turbine would actually cost money to run. This was the case because the inverter that converts energy from wind into a form that's usable by the mains constantly uses power, even when the turbine isn't turning.

A stronger wind would, of course, have generated more wind power and cancelled out the inverter's energy use but, according to Windsave's own estimates and other research, you need to be living in a very windy area to generate significant amounts of wind power. 

Visit the Carbon Trust's wind speed estimator tool to find out the average wind speed in your area before considering investing in a home wind power system. 

Wind turbine noise

Our wind turbine also made two distinct noises.

From the outside of the house it made a whooshing and whirring sound that wasn't excessive or annoying. From the inside however, the noise was more of a moaning, humming sound, changing in frequency as the wind rose and fell. This was a more disturbing noise that frightened our tester's children in the night.

As well as noise, our turbine suffered from some vibration at higher wind speeds, which was felt in the house. We suspect that the vibration was caused by imperfect mounting of the turbine blades, however.

Wind turbine cost

Our Windsave wind turbine cost £1,595 including installation. In our case, planning permission costs came to a further £200.

Do your research before you consider installing a home wind turbine

Home wind turbine test conclusion

The evidence is stacking up against home wind power in urban and suburban areas.

Our wind turbine experiment showed poor results for our suburban family home and other bodies such as the Carbon Trust suggest that in some cases carbon emissions saved by a turbine may not make up for emissions generated when it was made. 

Since our test, the Energy Saving Trust (EST) tested 38 building mounted turbines and found that no urban or suburban building mounted sites generated more than 200kWh of electricity – that's £26 of electricity – a year. 

In some cases, as with our own Windsave experiment, some wind turbines were found to be net consumers of electricity. This was because the majority of tested installations were positioned in locations with poor average wind speeds lower than the recommended 5-6 metres a second. 

Find out more about the EST's wind turbine field trial here.