Cool PV

The project investigated solutions for increasing the efficiency of system combinations consisting of hybrid collectors and heat pump systems. Because the electrical yield of PV modules increases with decreasing cell temperature, the PV modules are cooled by heat exchangers when hybrid collectors are used. Direct utilisation of this waste heat for water heating is not possible due to the low temperature level. New potential uses were therefore analysed through the use of heat pump systems.

Specifically, an attempt was made to use the available waste heat to increase the evaporation temperature of the heat pump and thus increase the annual coefficient of performance. The active utilisation of the ground collector as a heat store for load balancing between the availability and demand for waste heat was the focus of the analysis. Various control and hydraulic concepts were developed for this purpose and their overall energy efficiency was verified using dynamic system and building simulations.