Solar thermal

In contrast to photovoltaics (PV), solar thermal energy (ST) is used to generate thermal energy. The modules used for this purpose contain a special liquid, often called solar fluid. The mixture of water and antifreeze transports the heat via a circuit into the house and into a heat storage tank. This is then connected to the house's water network, for example. Once the fluid has cooled down again, it is fed back into the solar collectors.

There is also the option of converting the generated heat into electrical energy, although this is usually not worthwhile given the availability of photovoltaic systems.