Solar thermal systems use panels or tubes, collectors, to capture thermal energy from the sun which is often used for domestic hot water but also has a range of other applications. There are primarily two types of solar thermal panels available on the UK market: flat-plate collectors and concentrating collectors. Flat-plate. The evacuated tube solar thermal system is one of the most popular solar thermal systems in operation. An evacuated solar system is the most efficientand a common means of solar thermal energy generation. Flat plate solar thermal systemsare another common type of solar collector which have been in use since the 1950s. The main components of a flat plate panel are a dark coloured flat. Solar air heaters are mostly used for space heating and can be both glazed and un-glazed. They are among the most efficient and economicalsolar thermal technologies available and. Thermodynamic solar panelsare a new development in solar thermal technology. They are closely related to air source heat pumps in their design but are deployed on the roof or walls like.