Solar Thermal - FAQ


No – there are two types of solar panels and they are based on completely different technologies. Solar Thermal, also known as Solar Water Heating systems, supply only hot water. Solar PV or Solar Photovoltaic systems generate only electricity.

During the summer months, a solar water heating system can generate up to 90% of the hot water required for an average household; even on duller days some hot water can be produced, with the remainder being provided either by a conventional boiler or electric immersion heater. On average, a well-designed solar heating system will generate around 55% of the annual domestic hot water demand while also substantially reducing carbon emissions.

You need to select the type of solar collector which will suit your application. There is little difference in the performance between tubes or flat plate collectors. Flat plate collectors are generally used on pitched roofs, either on or in the roof, and they can also be used on flat roofs using A-frames. For façade or flat on the roof applications, evacuated tubes should be used. Individual tubes can be rotated to face the sun if the array is not quite facing south, to maximise the amount of energy available.

You will need to have an unshaded, sunny area to install the solar collectors, either on a pitched roof, flat roof or, for evacuated tubes, a wall with a Southerly aspect. If installing the collectors on the roof, it will need to be structurally sound. You will also need space for a solar hot water cylinder, which could be large than a standard cylinder. If you have a combi boiler, you may need to change your boiler to a system or heat only boiler to be compatible with solar thermal. We will be able to advise whether your property is suitable for a solar thermal system.

South facing is the perfect aspect for solar thermal; however an east/west array is available for roofs that do not face south and can collect solar energy throughout the day

Although you probably don't need Planning Permission for a solar thermal installation, it is advisable to check with your local planning officer, especially if your home is listed or in a conservation area.

Installation should take one to two days.

You should have your solar thermal system installed by an MCS certified installer. This is a requirement when claiming a Government incentive such as RHI.

Solar thermal installation is eligible under Green Deal and RHI.

Solar thermal systems require very little maintenance. The concentration of antifreeze in the system needs to be checked annually to ensure correct concentration. This can be done at the same time as your annual boiler service.

You need a hot water storage cylinder to store the hot water generated by the solar thermal system, so a heat only or system boiler is more suitable than a combi.


Membership logos