Solar water heating panels, usually fitted on a south (ish) facing roof, can provide up to 50% of a household’s hot water requirements. The panels work on dull days, as well as sunny, winter as well as summer. In the summer, they may be able to heat the water to a useful temperature without further heating being required, whereas in winter, they will at least heat the cold incoming water a certain degree, reducing the amount of fuel your boiler needs to burn to get the temperature up to that which you need.

Installation costs will be between £2,500 and £4,000, and you should expect to save £40-£60 a year. That’s a long payback period. What’s more, government grants tend to be for professional installation only. The VAT rate for materials installed professionally is 5%, but for DIYers it is the full 17.5%.