Experimental study on electricity generation performance of T‐type direct‐expansion solar PVT heat pump system

Abstract

Abstract Focusing on the electricity generation performance of a direct expansion solar PVT heat pump system, a novel T‐type optimized collector/evaporator was designed. The experiment used refrigerant R410a as the working medium and was conducted under the average winter ambient temperature of 16°C in Fuzhou. Through experimental comparison, the differences in panel temperature, electricity generation, and efficiency under different radiation intensities were tested against traditional PV panels and honeycomb PVT panels. The experimental results showed that the T‐type PVT system exhibited significant advantages under various weather conditions. The back panel temperature was reduced by 12.74, 8.52, and 13.06°C compared to traditional PV panels and honeycomb PVT panels, respectively, and it maintained a stable increase in electricity generation. The maximum instantaneous electricity output increased by 56.6% relatively, and the total electricity generation increased by 9.3% to 14.5% compared to traditional PV panels. The photoelectric efficiency reached 21.54% and 22.6%, surpassing traditional PV panels and honeycomb PVT panels, with measured values relatively increased by 1.7%, 2.38%, and 2.76%, respectively. Economic evaluation indicated that the T‐type PVT system could save on self‐generated electricity costs, achieving savings of up to 386.50 and 210.81 yuan/year compared to traditional PV panels and honeycomb PVT panels. The T‐type PVT system demonstrated clear advantages in self‐generated electricity costs, significantly reducing costs for application scenarios and providing strong support for the practical application of renewable energy technologies.

Keywords

• instantaneous electricity generation
• photoelectric efficiency
• solar radiation intensity
• T‐type direct‐expansion PVT heat pump system