The principal components comprise the

• solar water heater panel
• dual coil hot water cylinder
• water pump
• temperature controller to ensure that the hot water is available at the appropriate temperature

The principal installation costs are

• mounting the collector on the roof
• replacing the hot water cylinder containing a single coil with one containing a double coil
• modifying the plumbing

When sizing the system, it is most cosy effective to size according to summer needs; for a four person household, two panels 2m by 1 m would be typically required.

Costs

A typical installation would cost between £3,000 and £5,000 provided that the solar panels can be easily installed.

The amount of energy saved would typically be 1,500 kWh/year; this would cost about £150/year by electricity and about £75/year if supplied by gas.

Grants

To be eligible to receive a low carbon buildings grant you must undertake a number of energy efficiency measures and you must use an accredited installer and an accredited product. The overall maximum grant for a solar hot water system is £400 or 30% of the relevant eligible costs, whichever is the lower.

Details are given at the low carbon programme website see:
http://www.lowcarbonbuildings.org.uk/

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