A Novel Dual-Objective Metric for Temperature and Spatial Uniformity in Photovoltaic/Thermal Systems

In photovoltaic/thermal (PV/T) systems, the reduction in average temperature and improvement in spatial temperature uniformity are widely acknowledged as two critical objectives that necessitate simultaneous optimization. However, conventional cooling techniques are predominantly limited to single-parameter optimization, exhibiting an inherent inability to achieve balanced enhancement of both performance metrics. Consequently, this limitation may result in either compromised electrical conversion efficiency or accelerated performance degradation during long-term operation. To address this limitation, a novel cooling figure of merit (C-FOM) was proposed to quantify the multidimensional cooling effect of PV/T systems. By leveraging this comprehensive metric, the cooling effects of four conventional channel-based PV/T systems can be systematically evaluated using a 3D opto-electro-thermal-fluid coupling numerical model. Building on these insights, a V-type parallel channel was designed and further optimized in terms of the cross-sectional geometry to enhance the cooling effect. This work provides a systematic approach for advancing PV/T cooling strategies beyond single-parameter optimization, paving the way for high-efficiency, robust hybrid solar energy systems.