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Blog Post 11 February 2021

Could solar water heating work for you?

Solar water heating, often referred to as solar thermal, is a low carbon, renewable technology that uses energy from the sun to warm domestic hot water. It’s a sustainable alternative to heating systems that rely on fossil fuels, such as oil and gas-fired boilers.

Solar water heating systems use solar panels, called collectors, fitted to your roof. These collect heat from the sun and use it to heat up water that is stored in a hot water cylinder. A boiler or immersion heater can be used as a back up to heat the water further to reach the temperature you want.

The system works all year round, though you’ll need to boost the temperature of the water using a boiler or immersion heater during the colder winter months. Find out whether the technology could work for you.

How to make the most of solar water heating

If you do install solar water heating, make sure that as much of your hot water as possible is taken from the solar supply, rather than heated electrically in an appliance. This can include fitting a mixer shower rather than an electric shower (check with your plumber that the water pressure is sufficient).

You may get more out of your system if you use more of your hot water in the evening, after the solar has had time to heat it up. However, it’s more important to make sure that your back-up heating system is set up to come on at the right time.

Before you installed the solar panels, your boiler or immersion heater was probably set to give you a full tank of hot water in the morning. If you leave it like this, your system will always start the day with a hot tank and there will be nothing for the solar panels to heat during the day.

Your installer should advise you on how to set your hot water controls to get the most out of your new system, whatever time of day you use hot water.

Find out more about solar water heating, including costs, savings and maintenance.