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How to Buy Solar Panels

Solar Water Heating Installation

By Beth Askham

Article 11 of 12

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Solar Water Heating Installation

Our experts reveal all you need to know about solar thermal panels – from whether you need planning permission to tricks to maximise their efficiency. 

Thinking of installing solar water heating? We tell you what you need to know before you buy solar water heating panels.

Installing solar thermal panels will generate free hot water. Find out how to make solar thermal panel installation hassle-free.

The best location for solar panels

For maximum efficiency, you need to put your solar panels on a south-facing roof at a 30-degree angle to the horizontal (up to 65 degrees will still work in the UK), and keep the panels away from shadows (trees, buildings, chimneys, etc)

Some panels require regular checks of the unit and connections, or a wipe of the panel glass with mild detergent. Bear in mind how difficult this can be when panels are up on your roof.

Planning permission for solar panels

You won't need planning permission for most domestic solar panels, as long as they respect certain size criteria. But exceptions apply for listed buildings, buildings in conservation areas and World Heritage Sites. 

Contact your council to see whether you need to apply for planning permission for your solar panel. You'll also find more information about planning permission on the Energy Saving Trust's website.

Installing solar panel systems

A solar water-heating system involves pipe work, a thermostat and a hot water cylinder. 

You can add solar water heating panels to most existing hot water systems. Although you'll usually need to add an additional cylinder for pre-heated water, or change your existing cylinder for one with a twin coil.

It's difficult to use a solar water-heating system with a combi boiler because these are designed to take cold, mains-pressure water, and solar water-heating systems supply warm, low-pressure water. Some new combi boilers accept pre-heated water, so check with the manufacturer.

To find out which boilers are the most reliable, take a look at our boiler reviews

Maximising solar water-heating efficiency

In October 2011, the Energy Saving Trust released the results of its field trials of 88 solar hot-water systems. It found that proper installation, householders' behaviour, and insulation of the pipes and water tank are all key in improving the performance of a solar hot-water system, so you can save the most on your heating bills. 

System performances can be improved if the pumps and timers are set correctly. It also found that, in some houses, a lack of insulation on the hot water tank and pipes led to poorer performance.

Generally, however, solar thermal systems worked well, and 84% of the people who took part in the trial were either fairly or very happy with their system.

Interested in using solar panels to generate free electricity? See our buying advice for solar PV.

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