Techno economic analysis of integrating photovoltaic-thermal systems in ground-source heat pumps for heating-dominated regions

Ground-source heat pumps are known for their energy efficiency and potential to reduce carbon emissions. However, the inconsistency of heat exchange between borehole heat exchanger and soil in winter and summer in heating-dominated regions results in soil thermal imbalance. To address this challenge, this study investigates the integration of photovoltaic-thermal panels as auxiliary heat sources with ground-source heat pumps and assesses their viability across different heating-dominated regions. A system simulation model, which interfaces MATLAB and TRNSYS, was employed to evaluate the system performance under different heat source combinations. This study delves into the application prospects of these systems, considering various configurations and cooling/heating load ratios, while assessing their energy efficiency, economic viability, and environmental benefits. The results show that the use of photovoltaic-thermal enhances the heat pump coefficient of performance by 6.5 %, while maintaining the soil thermal balance. Larger systems with more panels yield better return in regions with relatively high cooling/heating load ratio. Lower panel capital costs and higher grid electricity prices improve the economic attractiveness of the combined system in regions with relatively low cooling/heating load ratio, with life cycle cost reductions of up to 40 % compared to traditional systems. The use of these panels can reduce the life cycle cost of conventional ground-source heat pumps by more than 30 % and their CO2 emissions by more than 50 % with moderate capital costs. This study provides data support and recommendations for the application of these integrated systems in heating-dominated regions.