With the phenomenal success of the Solar photovoltaic market in Britain, it's easy to forget about Solar Thermal, which uses energy from the sun to heat water rather than generate electricity. With typical British summers characterised by soggy barbecues, it's a technology often overlooked, the assumption being that there aren't enough sunny days to justify the investment. Yet it can make a surprising contribution to household hot water and heating requirements, meeting up to 55 percent of demand. In fact, the systems have to be carefully designed to prevent water boiling inside the thermal panels. Furthermore, hot water is provided not just during the summer but long after, up to eight months of the year.
How does solar thermal work?
A typical system will involve two to three panels installed on a south facing roof at 20-50 degrees, although they're still effective on east west-facing roofs. The solar collectors are either flat panel which resemble skylights, or evacuated tubes which are vertical rows of glass tubes. Hot water produced during the day needs storing for evening use and, because solar radiation in the UK is variable, there is usually the requirement to combine the solar thermal system with a supplementary system, such as a heat pump or traditional boiler.
How much does it cost?
A complete two-panel system including storage tank for a three bedroom house will typically cost from £5,000 fully installed with a guarantee of up to 25 years. A £300 Government cash-back scheme on new installations is available, and the forthcoming Renewable Heat Incentive scheme will pay homeowners for the heat they generate.
Jonathan Guppy, regional director,
Ecoliving (West Midlands and Central Wales).
Tel: 07715 109099.