The way the Government subsidises small renewable electricity generators is changing. It has been handing out one-off grants up to £2,500 to help with installation costs.

Now the grants have stopped. Instead your electricity supplier will pay you at a fixed rate for every kilowatt hour of electricity you generate, even if you use it yourself.

For solar photovoltaics (solar panels), the rate is 41.3p per kilowatt hour for people who start this year. If you export electricity to the national grid, your supplier has to pay you an extra 3p per kilowatt hour – that’s 44.3p in all.

Typically you will be paying about 13p per kWh for your electricity. So you can sell electricity for over three times what it costs to buy.

These rates are set for the 25-year lifetime of the deal between you and your supplier, and will rise with inflation.

But the rate for new agreements is set to go down in future years. So it pays to sign up early.