The Thermal storage tanks are available in different types, there are thermal storage tanks for underground horizontal installation, but they are also available as above-ground models. The aim is the storage of heat for example with thermal solar energy, heat pumps, etc. There are also concrete tanks available that are equipped with a heat exchanger for heat pump systems and heat recovery; - Tanks for thermal storage, lying underground - Tanks for thermal storage lying aboveground - Tanks for thermal storage standing aboveground - Tanks for thermal storage standing underground - Concrete tanks for thermal storage underground.