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Solar water heating

How Does Solar Water Heating Work?

By Sarah Ingrams

Article 1 of 4

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How Does Solar Water Heating Work?

A solar water heating system (or solar thermal system) heats water with panels fitted to your roof. Find out if it's right for your home.

Wondering if you should install solar water heating? We tell you all you need to know about solar water heating.

Solar water heating works differently to solar photovoltaic (PV) panels, as it provides hot water rather than electricity. You could have both if you have space on your roof – a solar hot water system shouldn't take up too much room. 

If you want to find out more about generating your own electricity using solar panels, see our guide to solar PV panels. Otherwise, keep reading to find out how solar water-heating works.

How solar water heating works

The illustration below shows how solar water-heating systems work.

Solar Thermal Panels

Types of solar water heating systems

There are two main types of solar water heating panels – flat plate and evacuated tubes (referring to the way the water interacts with the panel). Evacuated tubes are more efficient than flat-plate versions, so are often smaller but still generate equal amounts of hot water.

There are also drainback systems, which drain water from inside the solar panel when the pump is switched off. This prevents water from freezing or boiling inside the solar panel.

Solar water-heating installation 

You'll need to hire a professional to install your solar water-heating system. There are plenty of solar panel installers out there, so we recommend that you always collect a range of quotes to compare. 

You should only use installers and products that are certified by the Microgeneration Certification Scheme (MCS), then compare the estimates of costs and savings you're given by salespeople against other sources of advice.

We strongly recommend that you do your own research first, so read our guide to installing a solar water-heating system