Energy Facts

Solar Thermal

Solar water heating systems gather energy radiated by the sun and convert it into useful energy in the form of hot water. Solar water heating systems work alongside your conventional water heater to provide hot water.

A Solar Thermal system can provide almost all of a home's hot water during the summer months and about 50% of a home's hot water year round. In overcast conditions or when the temperature of the hot water is lower than required it is topped up by the main heating system in the house.

Such systems reduce carbon emissions by between 225-450kg CO₂. Typically the average domestic system can reduce carbon dioxide emissions by between 400 kilos and 750 kilos a year, depending on the fuel replaced.

A Solar Thermal system uses panels or collectors that would typically be fitted to a building's roof, but can also be fitted to the side of a building or laid out in a garden or flat area. These panels or collectors have liquid running under or through them in pipes, and which is heated by the sun's radiation.

There are two main types of panel or collector. The flat plate system uses an absorber plate with a transparent cover to collect the sun's heat. A tube system uses rows of glass tubes that each contains an absorber plate. These are connected to a manifold which transports the heated fluid.

The heat transfer system pumps the liquid heated by the sun through a closed loop or network of pipes. The heated liquid passes via the pipework from the solar panels and through the hot water cylinder. The heat in the pipework is transferred to heat the water in the cylinder, which is then available for domestic use.