Installing a wind turbine

Home wind turbines

We reveal what you need to know about installing a home wind turbine. From what you can expect to pay, how wind turbines work, whether you can earn money by generating your own renewable energy, and which types of wind turbines are available to buy.

Read on to find out more about home wind turbines, and whether a wind turbine is suitable for your home. You can also find out what happened when we installed our own wind turbine.

If you already know that you want to install a wind turbine, scroll down to see our checklist of the essential steps you need to take.

Choosing a home wind turbine

There are two types of home wind turbine: roof-mounted and freestanding mast or pole-mounted wind turbines. Home wind turbines can either be connected to the National Grid or stand alone, storing the energy they produce in a battery.

Home wind turbines come in a range of sizes, prices and powers, generating from under 100W to around 50kW. Smaller micro-turbines are often used to charge batteries, while those of 0.6kW upwards can also be used to generate electricity for houses and businesses.

Rooftop models vary from 0.5kW to 2.5kW in size while pole-mounted domestic turbines are often about 5kW to 6kW.

Wind turbine price

As an indication, the Energy Saving Trust (EST) estimates that domestic wind turbines (including installation and VAT) cost about (for UK):

• up to £3,000 for a roof-mounted 1 kW micro wind turbine
• between £9,900 and £19,000 for a 2.5 kW pole-mounted wind turbine
• between £21,000 and £30,000 for a 6kW pole-mounted wind turbine

Although micro roof-mounted wind turbines are cheaper, they are also less efficient and will produce a lot less electricity than pole-mounted ones.

Earn cash from wind power

Renewable energy has become more attractive since April 2010, when the government launched its Feed-in Tariff (FIT) scheme. Under this scheme, energy suppliers must pay you if you generate your own electricity through renewable energy – whether you use it to power your home or export it to the grid.

The scheme guarantees a minimum payment for all electricity generated, plus a separate extra payment for electricity you export to the grid. You'll also be saving money on your energy bills by importing less from the grid.

Terms and conditions apply to the scheme. For example, the wind turbine must have been installed after 1 April 2010 by a certified Microgeneration Certification Scheme (MCS) approved installer – so it's definitely worth looking into this before you get a wind turbine installed. To find out more and to see the FIT rates for wind turbines.

How does a domestic wind turbine work?

Electricity is generated when the blades are turned by the wind, a bit like a windmill. The amount of electricity generated depends on the speed and consistency of the wind. The generated electricity is ‘plugged-in’ via a 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.

Which? wind turbine test

The Windsave WS1000 was the first small wind turbine to generate a direct supply of electricity that was compatible with mains supplies. In 2008, we bought one from B&Q and had it installed to see how much electricity wind power could provide to a typical, suburban home.

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 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.

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 had an average of 4.7 m/s – just below this.

Wind turbine noise

Our wind turbine 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 making noise, our turbine vibrated 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.

Is wind energy right for you?

The amount of electricity generated by a small-scale wind turbine depends on the speed and direction of the wind in your area and other nearby obstructions, such as buildings, trees or hills, that could reduce wind speed or increase turbulence.

The EST's wind turbine study in 2009 concluded that fewer sites than previously predicted were suitable for the technology, and homeowners should first install an anemometer (wind gauge) for at least three months to determine the average wind speed for the location before investing in a wind turbine.

Many wind turbine manufacturers, and the EST, recommend installing at sites with a local average wind speed of 5m/s or more. The vast majority of UK households have an average wind speed of less than this.

Energy production increases with wind speed, up to a maximum level, and a minimum wind speed is usually necessary for turbines to start generating electricity. You should ask manufacturers for the specifications of their products when choosing a turbine, including the rated wind speed and energy generated.

Although small roof-mounted wind turbines are cheaper, they generate a lot less electricity than pole-mounted ones. So if you live in an area where wind speed is less than 5m/s, a roof-mounted turbine might not be a good investment.

Find out more about the pros and cons of wind turbines in our guide to the advantages and disadvantages of wind turbines.

Where to install your home wind turbine

Small-scale wind power is more suitable for remote off-grid locations where conventional methods of supply are expensive or impractical. Wind speed increases with height, so it’s best to have the turbine high on a mast or tower.

The best place for a wind turbine is a smooth-topped hill with clear exposure. As it will be free from excessive turbulence and obstructions such as trees, houses or other buildings. However, other areas may have a sufficient wind resource to make a wind turbine worthwhile. Building-integrated wind turbines can be suitable for urban locations. But findings from the EST's field trial of 38 building-mounted turbines showed that performance was generally lower than expected, usually because of low wind speeds and poor positioning.

The trial also looked at 19 freestanding turbines. It found that freestanding or pole-mounted turbines, when properly installed, performed well.

Planning permission for home wind turbines

As long as some limits and conditions are respected, most domestic wind turbines should not require planning permission under new permitted development rights. Contact your local authority to find out if you need planning permission..

If planning permission is required, your neighbours will be consulted to voice any objections they have to the wind turbine. For this reason it's good practice to speak to your neighbours before investing time and money in the planning process.

Source: which.co.uk/

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Installing a wind turbine