Solar water heating systems use solar panels (‘collectors’) fitted to the roof. They collect heat from the sun and use it to warm water which is stored in a hot water cylinder.
There are two types of collectors; evacuated tubes and flat plate collectors. Flat plate collectors can be fixed either to roof tiles or integrated into the roof.
A boiler or immersion heater can be used as a back up to heat the water further to reach the temperature set by the cylinder thermostat when the solar does not reach the temperature.
Solar panels should be positioned in a southerly direction for maximum potential. They can be mounted directly onto a sloping roof or onto a frame for a flat roof and various fixings and brackets are available.
Solar panels utilise both direct and diffused sunlight, so they even work on a cloudy day. The UK receives about 65% of the amount of solar radiation received in the south of Spain. Direct radiation on a sunny day accounts for around 40% and diffused radiation on cloudy days accounts for around 60% of the total radiation in the UK.
A well sized typical solar panel installation will provide approximately 80-90% of the hot water requirement in summer, approximately 40-50% in spring and autumn and approximately 20-30% in winter, averaging out at over half of the typical annual domestic hot water requirement.
Planning permission is not required to install solar panels onto domestic properties.
