Solar Hot Water
There are a lot of solar systems now available for heating domestic hot water (DHW), and most households are eligable for a government grant if you use an accredited installer.
This is perhaps the place to start if you want to save energy (after you've conserved as much as you can, of course!).
Most properly designed systems will save up to 70% of the cost of heating your domestic hot water, and it is worth choosing quality components that are more likely to be reliable over the long term. Solar collectors have come a long way since the early experiments with radiators working in reverse, painted black!
Nowadays the panels contain sophisticated materials that absorb and retain more heat, but essentially the principle is the same: heat from the sun (even on a cloudy day) is absorbed and transferred to a working fluid, usually a water/glycol mix. This fluid is then piped to a coil in your hot water tank to heat your domestic hot water.
Collectors come in two types - flat plate and evacuated tube:
- Flat plate collectors can be integrated into the roof in a similar way to a 'velux' window or sit slightly proud
- evacuated tube collectors are more efficient and so take up less roof space.
A typical system comprises collectors, usually sited on a south-facing roof, a twin coil cylinder (one coil for the solar system and one for a conventional boiler) and a control station. The cylinder will usually fit inside an airing cupboard and can be unvented (supplies mains-pressure hot water) or vented.
Integrating solar with combi boilers is possible, but usually requires the use of a cylinder. Energy-saving installations attract a reduced rate of VAT at 5%.
