Research out of the SP Technical Research Institute of Sweden has provided proof of concept for a novel hybrid renewable energy system featuring combined hybrid solar PV and geothermal power according to Renewable Energy.
The new concept is based around a system, hybrid solar PV, ground-source heat pump GSHP and borehole thermal energy storage ground source. The result is a system where the outputs of each technology complement each other and carry the potential to increase energy efficiency and cost effectiveness of individual components.
One important feature of the system is the role hybrid solar PV plays. Unlike normal solar PV, hybrid solar PV is a popular and well-established method of cooling solar PV cells. These hybrid solar PV modules consist of conventional PV cells with embedded systems containing some form of cooling agent, either water or air, which is circulated through the panels. The goal is to decrease PV cell temperatures, because overheating through solar radiation or ambient heat reduces PV cell efficiency significantly.
Ms. Gervind explains the cooling process – water is heated to around 10 degrees C, then it is directed into the cold side GSHP system and used as a heat source. The surplus heat is then directed to the boreholes. Here, the thermal energy of water is absorbed by the surrounding ground as a result of a temperature differential that arises from the ambient temperature of the ground being between 2-3 degrees C. The cooled water is then cycled back into the system and re-used in the cooling of PV panels in a closed-loop system.
The project is supported by the Swedish Energy Agency together with Energiförbättring Väst. The system was piloted in 2015 on the west coast of Sweden over 70 terraced houses.
Monitoring system performance allowed researchers to make mid-study adjustments. They have already begun conducting a follow-up study to investigate key performance issues.
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