NUMERICAL STUDY ON THE THERMAL AND ELECTRICAL PERFORMANCE OF CONCENTRATED PHOTOVOLTAIC CELL USING RIBBED MICROCHANNELS WITH PARALLEL PCM CAVITIES

This study presents a new hybrid cooling strategy for concentrated photovoltaic (CPV) cells by incorporating ribbed microchannels and composite phase change materials (CPCM) within a concentric copper-PV cell assembly. The ribbed channels are designed with a convergent-divergent profile, which enhances local convective heat transfer. Meanwhile, the phase change materials (PCM) cavities, aligned parallel to the coolant flow, passively absorb thermal loads through latent heat storage. Various flow configurations were evaluated, including a distributed Reynolds number scheme with higher central Reynolds numbers and lower side Reynolds numbers. Unlike traditional passive PCM systems that completely melt and quickly transition into the less effective sensible heating phase, this hybrid system achieves up to 70% PCM melting without reaching full saturation. This prolongs its ability to effectively regulate temperature. This optimized cooling approach reduces the cell temperature gradient by approximately 18.6% and increases electrical efficiency by about 1.7% compared to uniform flow systems. The heat balance shows that CPCM-based hybrid PCM-water cooling absorbs 20%-25% more heat than water-only and 10%-12% more than OM-37, thereby lowering residual cell heat and enhancing CPV stability under high solar flux. Overall, the combination of enhanced convection and prolonged latent cooling significantly improves CPV performance while requiring minimal additional pumping power.