Solar hot water heating is one of the cheapest technologies to install and has a shorter payback time than most other forms of alternative energy. The real payback time will be determined by fuel price changes over the next 25 years.

It should also be remembered that a solar system could also add value to the property.

• Energy savings

Producing 50-70% of the buildings hot water requirement from renewable energy can help protect against future energy price increases, specifically gas prices.

• Carbon savings

Installing a solar hot water system can help alleviate global warming and reduce the buildings impact on the environment. The average domestic system can reduce carbon dioxide emissions by 0.4-0.75 tonnes (or 400-750kg) per year, depending on the fuel replaced.