Generating domestic hot water (DHW) from solar panels has moved into
the mainstream. We can supply systems to heat most of your DHW for
approximately 4 months of the year, in the remaining 8 months the
incoming water will be heated to varying degrees by the system, so
that even in winter the incoming 10degree water will be preheated
to perhaps 30degrees before its topped off by the boiler/immersion.
These savings make a significant improvement to your fuel bills. Importantly
modern systems do not need direct sunlight, they will still be heating
water on cloudy days.
Power costs have been increasing at about 10% annually, with our reliance
on imported Gas from Russia and the Middle east, this is unlikely
to change. Once funded a solar system runs on a 40watt pump. If we
assume that the solar system provides about 65% of a households water
and an equivalent cost of 15p/kWh. The annual Hot Water cost is £635
for a house with 150 Litre tank (at 65% solar produced that is a saving
of £412/annum). So with a 10% increase / annum we are looking at 6-7
year payback. This is set to be further improved by the Government
backed Renewable Heat Incentive due to be introduced in 2011. This
pays a fixed income likely to be 18p for every kilowatt hour of heat
There are a number of systems available, either Heat Tube collectors
or Flatplate collectors. They are either installed over the top of
the slates/tiles or the flatplate collectors can be mounted into the
roof itself. This eliminates the need for slates/tiles on a new build
or refurbished roof etc.