Using infra red power to heat your hot water
Many people install solar panels onto their roofs to generate their own renewable electricity and reduce their bills.
But did you know that you can also use solar energy to heat your water for showers, baths and taps?
You can do this with something called a solar thermal system.
How it works
Instead of solar PV panels – which work by directly converting the sun’s energy into electricity – a solar thermal system uses solar collectors.
There are two types.
Two types – Evacuated tubes are a set of glass tubes, while flat plate collectors are box-like structures.
Both attach to your roof. Filled with a mix of water and antifreeze, these collectors convert the infra-red part of light into heat.
Once the fluid inside them is heated, it’s pumped round a cir- cuit, which passes through a hot water cylinder.
The heat is transferred by a copper coil, so the water coming out of your taps isn’t the water from inside the collectors.
Benefits
You will have your own supply of hot water from a renewable source.
It will also save you money on your bills – £55 a year when replacing gas heating or £80 a year when replacing an electric immersion heater.
The system’s also cheap to maintain, with a small number of inexpensive parts.
Capacity
Because sunshine varies, a solar water heating system won’t provide 100 per cent of your hot water.
According to the Energy Saving Trust, it will provide you with 90 per cent of the hot water you need in the summer and 25 per cent in the winter.
A conventional boiler or immersion heater normally makes up the difference. Installation requirements
It’s best if your home faces south.
You’ll need between two and five m2 of space on your roof, with no shade from other buildings, or from chimneys or from trees.
Many combi boilers don’t accept pre-heated water.
If you have one, it most likely won’t link up.
However, if you already have a hot water cylinder, then you may be able to connect the hot water cylinder to the collectors – as long as it has a twin coil inside.
Furthermore, this system is only for hot water – so won’t heat your home.
Installation costs
Costs vary, depending on the number of collectors, the size of your home and the specific system you choose.
But expect to pay somewhere between £2,000 and £6,000.
To find a good installer, search on the Microgeneration Certification Scheme’s website.