Reliable and cost-effective microchannel cooling for hotspot suppression in high-concentration photovoltaic modules

• Four-compartment microchannel heat sink improves cooling uniformity by up to 76%. • Average module temperature reduced by 17.7% vs. single-compartment design. • Cooling upgrade boosts electrical power output by 3 W per module. • Payback period reduced to 3.28 years in thermo-economic analysis. • Figure of Merit (FoM) shows up to 33% higher thermal–hydraulic efficiency. Hotspot formation in high-concentration photovoltaic (HCPV) modules reduces electrical efficiency and accelerates material degradation, limiting system reliability and lifespan. To address this challenge, this study proposes a multi-compartment microchannel heat sink (MCHS) design to improve cooling uniformity in dense-array HCPV modules. A conventional single-compartment MCHS was reconfigured into two- and four-compartment designs, maintaining identical external dimensions for manufacturability. Three-dimensional CFD simulations in ANSYS, validated against published experimental and numerical data, were used to assess thermal, hydraulic, and electrical performance under varying coolant flow rates and flow arrangements. The four-compartment MCHS outperformed all other configurations, achieved 76 % better temperature uniformity, reduced average module temperature by 17.7 %, and increased the Nusselt number by 71 % compared to the baseline at 400 g/min (Re ≈ 800). Electrical efficiency improved by 1.7 %, exergy efficiency by 2.3 %, and power output by 3 W. A Figure of Merit (FoM) analysis confirmed up to 33 % higher thermal–hydraulic efficiency relative to the baseline. Arrhenius-based reliability modelling further indicated a potential lifetime extension of more than threefold. Thermo-economic analysis showed a 2.16 % higher electrical power gain and a payback period shortened to 3.28 years. These results demonstrate that multi-compartment MCHS designs provide a scalable, reliable, and economically viable solution for hotspot suppression, enhancing efficiency, uniformity, and economic returns for both terrestrial and space-constrained HCPV applications.