Performance Analysis of Nanofluid-Assisted Photovoltaic Thermal (PV/T) Coupled Ground Source Heat Pump System

Ground source heat pump (GSHP) systems offer a low-carbon heating and cooling solution for decarbonizing buildings. However, they suffer from performance degradation due to ground thermal instability in heating-dominated regions. On the other hand, Photovoltaic/thermal (PV/T) systems suffer from high temperatures that significantly reduce efficiency. PV/T systems can be combined with GSHP systems to act as a secondary source to the heat pump, thus reducing the load on the ground. The combination of GSHP and PV/T systems is a promising approach to improve the performance/efficiency of both technologies. The GSHP provides a cooling effect to the PV/T, while the PV/T helps to replace the heat extracted from the ground to reduce the thermal imbalance of the GSHP system. This study created a hybrid system by incorporating a PV/T system into a GSHP system installed at Sivas Cumhuriyet University. In this hybrid system, the performance of 1% concentration nanofluid was investigated. It is observed that the system supplemented with NF reduces the fluid temperature at the PV/T outlet by about 15.50% and increases the outlet temperature of the ground heat exchanger by about 6.2% compared to the system without NF. Furthermore, based on the reduction in PV/T outlet fluid temperature and the temperature coefficient of power, the relative electrical efficiency enhancement was theoretically estimated to be approximately 1.1%. It is also observed that NF increases the temperature of the fluid inside the heat exchange tank by about 4.05%.