The 1st requirement for any solar thermal hot water installation is a large unshaded South facing roof area (preferably 45 deg) of at least 3m2.
A South facing vertical wall can also be utilised, but the solar panel must be of a direct flow type.
An A frame is available for flat roofs to enable the 45 deg angle.
There are two types of thermal hot water panels, flat plate and evacuated tubes.
Evacuated tubes are always more efficient than the flat panels, and are more suited to the U.K. climate.
The panel is simply fixed to the roof battens by removing the tiles, which are then replaced back to the original position with the solar panel mounted above.
The two copper pipes or stainless steel pipes from the panel are then fed through a special solar flashing tile to the cylinder.