Solar water heating systems use solar panels, called collectors, fitted to your roof. These collect heat from the sun and use it to warm water which is stored in a hot water cylinder.
There are two types of solar water heating panels, they are evacuated tubes and flat plate collectors. Flat plates collectors can be fixed on the roof tiles or integrated into the roof. A traditional boiler or immersion heater can be used as a back up to heat the water further to reach the temperature set by the cylinders thermostat when the solar water heating system does not reach that temperature. Larger solar panels can also provide energy to heat your building as well – though usually only in the summer months when home heating is unnecessary.
For more information from the Energy Saving Trust on solar thermal systems please visit their website.