Numerical and experimental investigation on solar photovoltaic-thermal assisted heat pump systems using different kinds of solar cells

Mono-crystalline silicon (c-Si) solar cells dominate 95 % of the market but face temperature-related challenges that impact their efficiency and lifespan. This study introduces a photovoltaic-thermal (PVT) heat pump system to mitigate cell temperature, improve efficiency, and utilize waste heat. A comparative analysis across c-Si solar cell types is presented, supported by an energy loss model for photovoltaic modules and a mathematical model of the PVT heat pump system. The energy distribution for PERC (Passivated Emitter and Rear Cell), TOPCon (Tunnel Oxide Passivated Contact), and HJT (Heterojunction with Intrinsic Thin-film) modules is analyzed, and their temperature coefficients are calculated. The internal heat source encompasses 66–70 % of total incident solar energy, primarily from thermalization (29–30 %) and sub-bandgap (18–19 %) losses. The HJT module demonstrates the lowest temperature sensitivity. Simulations align with experiments, indicating significant influences of ambient temperature and solar irradiance on thermal efficiency and coefficient of performance (COP). Over typical days, the HJT-PVT exhibites a 13–15 % increase in electricity output over the PERC-PVT. However, differences in thermal efficiency and COP among three systems remain within a 2 % range. The system's COP reaches 7.24–7.34 in summer, compared to 4.80–4.83 in winter. Consequently, employing high-efficiency photovoltaic cells is advantageous for optimizing the system performance.