Patent ID: 8096293

Claim:
A liquid-heating system comprising: a solar energy collector exposed to solar radiation; a geothermal heat exchanger buried in the ground at a depth between 0.5 m and 5 m; a heater through which a liquid to be heated passes; a heat pump having a sink side connected to the heater and a source side connected to the geothermal heat exchanger or to the collector; and first valve means connected to the collector, the exchanger, and the heater for in one position connecting the collector to the heater such that heat collected by the collector is applied to the heater, and in another position connecting the collector to the geothermal heat exchanger such that heat collected by the collector is applied to the ground surrounding the geothermal heat exchanger; second valve means connected to the collector, to the geothermal heat exchanger, and to the source side of the heat pump for in one position connecting the collector to the heat pump such that heat collected by the collector is applied to the heat pump, and in another position connecting the geothermal heat exchanger to the heat pump such that heat is extracted from the ground surrounding the geothermal heat exchanger and applied to the heat pump; a distributor in the collector for storing the heat-exchange medium of the collector; a first set of tubes connectable to the collector; and a second set of tubes connectable to the source side of the heat pump, both sets of tubes surrounding and extending radially and horizontally from the distributor.