Patent attributes
The invention provides a system for collection of thermal energy. The system comprises an energy collector, an energy reservoir, an energy collection medium enclosed in a loop allowing fluid flow of the energy collection medium between the energy collector and the energy reservoir in a forward flow from the energy collector and in a backward flow to the energy collector for transferring energy between the energy collector and the energy reservoir, a collector pump adapted to control a flow rate of the energy collection medium, and a reservoir temperature measuring device being adapted to measure a reservoir temperature of the energy reservoir. Furthermore, the system comprises at least one heat pump comprising a cold side, a warm side, and exchange means for exchange of thermal energy from the cold side to the warm side, the cold and warm sides being arranged to decrease the temperature of the energy collection medium in the backward flow by operation of the heat pump, and a control unit adapted to control the operation of the heat pump and thereby an exchange rate by which thermal energy is exchanged between the energy reservoir and the energy collection medium. The control unit is adapted to control the operation of the heat pump dependent on the measured reservoir temperature.