Full-spectrum radiative cooling for enhanced thermal and electrical performance of bifacial solar photovoltaic modules: A nationwide quantitative analysis

Bifacial photovoltaic (bPV) technologies have been garnering increasing attention in recent years due to their ability to generate more power than conventional PV systems. Passive radiative cooling through spectrally selective absorption/emission is considered one of the most practical and cost-effective solutions for the thermal management of bPV modules. In this study, a full-spectrum radiative cooling (FRC) strategy was proposed to maximize the thermal and electrical performance of bPV modules by enhancing above-bandgap absorption, sub-bandgap reflection, and thermal radiation. A multi-physics model was established to characterize bPV performance, enabling analysis of the module's spectral and thermal responses to full-spectrum light under dynamic weather conditions. The proposed model was validated through outdoor experiments with a commercial bPV module, demonstrating good prediction accuracy. To quantify the radiative cooling effect of the ideal FRC strategy and compare it with the ideal traditional radiative cooling (TRC) strategy, a nationwide simulation analysis was conducted across 32 cities in China. The results indicate that the ideal FRC strategy can achieve an annual average temperature reduction of 2.3–4.4 °C and an additional power gain of 7.3%–8.4% for commercial bPV modules. In comparison, the ideal TRC strategy can only achieve an annual average temperature reduction of 1.1–2.2 °C and an additional power gain of 0.38%–0.89%. Results from correlation analysis and sensitivity analysis show that among environmental parameters, wind speed has the most significant positive effect on lowering module temperature, while precipitable water vapor has a relatively small negative impact. Overall, this research demonstrates that the FRC strategy holds great potential for reducing temperature and boosting power output in PV devices, paving the way for promoting the development of sustainable and efficient PV systems.