Experimental investigation of the energy performance of a photovoltaic-thermal assisted ground source heat pump system for net plus energy houses

This study investigates the experimental analysis of the energy saving potential of integrating a photovoltaic-thermal (PVT) assisted ground source heat pump system under heating season operation. The demonstration building is an energy plus solar house located in Daejeon, South Korea. The coefficient of performance (COP) was measured during heating and domestic hot water operations to compare the energy supply efficiency of the proposed system and conventional systems. The results showed that the COP of the heat pump system was observed 4.5 for heating and 3.9 for domestic hot water. The ground source operation achieved COPs of 4.6 for heating and 4.4 for domestic hot water, while the PVT assisted ground source operation achieved COPs of 5.2 for heating and 4.4 for domestic hot water. The electrical and thermal utilization ratio of the PVT system were 7.5 %-21.2 % during the heating season. The seasonal performance factor and seasonal performance factor in grid of the proposed system showed 4.9 and 5.3, respectively. The experimental results confirmed that the PVT assisted ground source heat pump system is more energy-efficient with reducing carbon emissions compared to conventional systems.