This design is particularly suited to the UK environment to heat water as they respond fast to changing temperatures and are efficient at a wide range of sun angles, thus being more efficient on semi-overcast days and at the UK latitude.
A typical collector contains approximately twenty tubes, the sun’s heat passes through the external tubes and heats up the inner tubes, which in turn heat up the water in the internal pipe which is then transferred to your hot water storage tank, usually indirectly via a coil.
This system is most commonly used in conjunction with a conventional boiler topping up the temperature on colder, cloudy days.
An efficient system can produce up to 70% of all of your hot water needs all year round. A keenly priced source, a well-sited position and a well-installed system can be a good investment with a relatively short pay-back period. There’s nothing to beat standing under a hot shower that you know was entirely heated by sunlight.
And additionally – the introduction of the Renewable Heat Incentive –
see www.guardian.co.uk/environment/2011/mar/10/renewable-heat-incentive will mean that you will be paid approximately £300 grant to have a system installed and then approximately 8.3 pence per kilowatt hour for the energy you produce (assuming you have a south facing roof with little overshading) – making Solar Thermal an even better investment.