Techno-economic and environmental assessment of source-side and load-side PV/T-assisted ground source heat pump systems

Abstract

Building heating consumes substantial energy and contributes significantly to global carbon emissions. Integrating photovoltaic/thermal (PV/T) modules with ground source heat pumps (GSHP) offers a promising sustainable solution, effectively addressing the soil thermal imbalance and low energy efficiency inherent in conventional GSHP systems. This study proposes and mathematically models two hybrid configurations: PV/T modules integrated on the source side and the load side, respectively. Component models were validated against experimental data (maximum error < 6%) to conduct a comprehensive 20-year comparative assessment across energy, economic, environmental, and soil thermal balance dimensions. Simulation results indicate that both configurations successfully mitigate soil temperature decline, achieving long-term soil thermal balance and effective seasonal solar thermal storage. However, the source-side PV/T-GSHP system exhibits superior overall performance. It delivers a higher Primary Energy Ratio (PER) and Energy Efficiency Ratio (EER), a lower Levelized Cost of Energy (LCOE) of 0.36 RMB/kWh, an 11.14% higher annual total cost-saving rate, and an 8.47% improvement in CO₂ emission reductions compared to the load-side system. These findings provide optimized configuration strategies and reliable performance data for PV/T-GSHP systems, significantly promoting the efficient utilization of solar-geothermal hybrid energy in low-carbon building applications.