Solar water heating

How does it work?

For domestic hot water there are three main components

• Solar panels or collectors - are fitted to your roof. They collect heat from the sun's radiation. There are 2 main types of collector:
  • Flat plate systems - which are comprised of an absorber plate with a transparent cover to collect the sun's heat, or
  • Evacuated tube systems - which are comprised of a row of glass tubes that each contain an absorber plate feeding into a mainfold which transports the heated fluid.
• A heat transfer system - uses the collected heat to heat water;
• Hot water cylinder - stores the hot water that is heated during the day and supplies it for use later.

The benefits

Solar water heating can provide you with about a third of your hot water needs. The average domestic system reduces C0 ₂ by around 325kg per year and about £65 a year of your hot water bills, when installed in a gas heated home.

All savings are approximate and are based on the hot water heating requirements of a 3 bed semi detached home.

Is it suitable for my home?

Solar water heating can be used in the home or for larger applications, such as swimming pools. For a domestic system you will need 3-4 square metres of southeast to southwest facing roof receiving direct sunlight for the main part of the day. You'll also need space to locate an additional water cylinder if required.

Choosing a system suitable to your needs requires consideration of a range of factors, including the area of south facing roof, the existing water heating system (e.g. some combi boilers aren't suitable) and your budget. A competent accredited installer will be able to assess your situation and discuss with you the best configuration to meet your needs.

In England, changes to permitted development rights for microgeneration technologies introduced on 6th April 2008 have lifted the requirements for planning permission for most solar water heating installations. Roof mounted and stand-alone systems can now be installed in most dwellings, as long as they respect certain size criteria. See our planning permission for renewable energy technologies for more information. Exceptions apply for Listed Buildings, and buildings in Conservation Areas and World Heritage Sites.

In Wales, Scotland and Northern Ireland, the devolved governments are currently all considering changes to their legislation on permitted developments, to facilitate installations of microgeneration technologies, including solar water heating. Legislation is expected in all three countries later this year. Until then, householders in Wales, Scotland and Northern Ireland must consult with their local authority regarding planning permission.

Solar water heating systems tend to require little maintenance

Installation and maintenance costs

The typical installation cost for a domestic system is £3,000 - £5,000. Evacuated tube systems are more advanced in design than flat plate, and so tend to be more expensive.

Solar water heating systems generally come with a 5-10 year warranty and require little maintenance. A yearly check by the householder and a more detailed check by a professional installer every 3-5 years should be sufficient (consult your system supplier for exact maintenance requirements).

Where can I find out more about installation?

The BERR funded low carbon buildings programme provides grants to help with the costs of installing solar water heating technologies.

To be eligible for a grant you will need to use a certified installer and products.

• Find certified installers
• Find certified products

Certification for products and installers within the low carbon buildings programme is now provided through the Microgeneration Certification Scheme managed by BRE Certification.

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