What is Solar Hot Water (SHW) technology?
Active solar Heating technology means using
radiation for heating hot water. In this way, the abundant free
energy from the sun can be harnessed to meet a large part of
the domestic hot water demand, and reduce the consumption of
conventional fuels. The use of these fuels is now widely recognised
as causing climate change, and pollution.
The UK receives a vast amount of solar energy
which on average equals 60-65% of the annual amount received
on the equator. The available range of high quality products
enables householders to make effective use of the sun. Thus,
even in spring and autumn, and on clear, but cold winter days,
the solar hot water system can prove useful.
The principle system omponents are solar collectors,
a pre-heat cylinder (optional) pump, controls, connecting pipes,
the normal hot water cylinder (or a replacement dual coil cylinder)
and a conventional heat source.
How does a typical system work?
The principle is straight forward. When the
sun is shining, water is pumped through the solar array, and
is heated by solar energy. This heated water then flows through
a heat exchanger, or cylinder coil, warming the water stored
within the hot water cylinder. If necessary, a boiler or other
external heating source provides top up heating. In addition,
standard type immersion heaters may be employed.
An electronic controller constantly compares
the temperature of the solar collectors with the temperature
at the lower end of the hot water cylinder. Whenever the array
is hotter than the cylinder (by about 3 deg.C) the controller
will switch on the circulating pump/ A mixture of water/antifreeze
solution is then circulated through the array and the cylinders
heat exchange, heating the cylinder in the same way as a central
What are the benefits of an individual
domestic hot water system?
- Provides you with your own clean source
of hot water that also helps reduce global warming.
- Reduces energy bills, since sunshine
is free. Can, in certain circumatances, increase the value
of a property
- Extremely low maintenance, with a long
service lifetime of 20-30 years.
- Silent in operation, and visually unobtrusive.
- Increase awareness of energy use, and
encourages more energy efficient behaviour