Feeling green?Fitting a domestic wind turbine could not only help save the environment but can also save you money.

And as the world's largest wind turbines have been turned on off the Merseyside coast, here’s what you need to know before you get one.

1. Advantages

The advantages of having a wind turbine are that any electricity generated by it is free (although you obviously have to pay for the turbine and installation) and your home's CO2 emissions are reduced.

Your turbine should also earn you money through the Government's Feed-in Tariffs scheme. This pays you not only for the electricity you generate and use, but also for any you export to the national grid.

[Read more: The world's largest wind turbines have been switched on in the UK]

2. Different types

There are two types of domestic wind turbine: pole or mast-mounted ones, which are freestanding and typically around 5kW-6kW in power, and building or roof-mounted ones, which are usually around 1kW-2kW.

Turbines store the electricity they generate in batteries, so it can be used on days when there's little or no wind, or are connected to the national grid.

Roof-mounted wind turbines are the cheapest option. The Energy Saving Trust says a roof-mounted 1kW micro system costs up to around £3,000, rising to £21,000-£30,000 for a 6kW pole-mounted system.

[Read more: Grand Designs’ Kevin McCloud’s 7 tips for transforming your home on a budget]

3. Think about location

Your home's location will determine how useful a wind turbine will be.

The key things are the speed and direction of the wind, and if there are obstructions, such as trees and buildings.

Because of this, wind turbines aren't suitable for many homes - to find out about yours, try using the Energy Saving Trust's Wind Speed Prediction Tool. This provides an estimated wind speed for your location.

4. Measure the wind speed

The next step is to use an anemometer (wind gauge) to measure how much wind your home actually gets.

Most turbines need a minimum wind speed before they can start generating electricity, so check with the manufacturer before investing in one.

The ideal location for a wind turbine is a smooth-topped hill that's exposed and free from obstructions and turbulence.

5. Get the right permission

Planning permission may be required for a domestic wind turbine - check with your local council's planning department.

If your home's leasehold, you may also need the permission of the freeholder, especially if you want to put the turbine on the roof, as the roof of the building is usually owned by the freeholder.

What are your thoughts on wind turbines? Tell us in the Comments box below.