Thermal Panels

The term 'solar panel' in common usage is equally likely to be applied to Solar Thermal Collectors.

While Photovoltaic Solar Panels convert Photon particles from the sun directly into electricity, Solar Thermal Collectors generally heat water or other such liquid. Solar Thermal Collectors generally do not generate the electricity required in a household to provide lighting, charge electrical equipment or to power appliances. However, they can provide a good supply of hot water for heating or washing, greatly reducing a household's gas or electricity requirements.

Solar Thermal Collectors are a weatherproofed, insulated box containing a black metal absorber sheet with built in pipes is placed in the path of sunlight. Solar energy heats up water in the pipes causing it to circulate through the system by natural convection (thermosyphon). The water is usually passed to a storage tank located above the collector. Most Solar Thermal Collectors are cheaper and easier to construct than Photovoltaic panels, and many high street stores such as B&Q stock Solar Thermal Panel kits.

Solar water heating systems can usually be integrated into your existing hot water system. System choices and installation times depend on your existing heating system, the amount of storage space you have and the orientation of your roof.

The energy saving trust supplies the following advice for installing solar water heating systems

Technologies

Flat plate and evacuated tube collectors (panels on the roof).

Standards

Collectors tested to BS EN 12975 or BS EN 12976.

Installed cost

Typically £4,000 to £6,000.

Grants available

Call the Energy Saving Trust on 0800 512 012 for details of any local support available.

Other financial

The Renewable Heat Incentive (RHI) is due to be introduced in 2011 and will support give on-going support to eligible renewable heating installations. For the latest information on RHI visit energysavingtrust.org.uk

Running costs

Virtually none, a small electric pump is usually required.

Savings

A typical solar water heating system will provide over 1,000 kWh of hot water per year, saving around £50 per year in a home with gas water heating. RHI not included.

Maintenance

Minimal annual checks with a service every three to five years.

Space issues

Cylinders are larger than normal and may not fit in some airing cupboards.

Energy availability

Throughout the year but mostly in summer months. Boiler is still required as a top up to meet all your hot water demands.

Planning issues

Generally don’t require permission however there are exceptions and limitations.

Installer issues

Choose an installer certified under the Microgeneration Certification Scheme (MCS) - see microgenerationcertification.org Check the installer is a member of the REAL Assurance Scheme visit realassurance.org.uk for more information.

CO2 emissions

Virtually none during operation. Can reduce household emissions by 260kg CO2 per year when replacing gas heating.

Other issues

Best results from roofs facing south. Panels need to be tilted 30-45° from the horizontal. Will not work with some combination boilers – seek advice from your boiler manufacturer.