The invention relates to a thermal solar system comprising a collector that is connected to a heat sink, in particular a heat storage medium, by way of a solar circuit containing a heat exchange medium. In order to reduce the danger of overheating of the system during idling and to improve the efficiency of the solar system, it is proposed that the solar circuit be connected temporarily to at least one heat exchanger by way of a valve control unit, said heat exchanger being disposed at a hot side of a thermogenerator receiving an inflowing heat flow and that a thermal insulation reduces the exchange of thermal energy between the collector of the thermal solar system and the heat exchanger.