Feasibility of Flat-Plate Heat-Sinks for Ultra-High Concentrations (> 2000 Suns) Using Microscale Solar Cells

Concentrator photovoltaic (CPV) systems replace semiconductor material by cost-efficient optical elements. The potential cost reduction of these systems is closely related to the concentration factor because higher light concentrations imply lower amount of semiconductor material required for the solar cells. Thus, one promising way for improving this technology is moving towards ultra-high concentration levels (>2000 suns). However, the thermal management at such ultra-high light fluxes is difficult. The use of small-sized solar cells is beneficial for improving the thermal management. Among the possible cooling strategies, the use of flat-plate heat-sinks for passive cooling, if feasible, would be the simplest way to dissipate heat and would accelerate the development of ultra-high CPV prototypes. In this work, a thermal 3D finite-element model is used to investigate the possibilities of flat-plate heat-sinks for passive cooling at concentration ratios not tested to date (2000-10000 suns). Results show that a micro solar cells of 0.5mm x 0.5mm area can be thermally handled with conventional Aluminium flat-plate heat-sinks up to 10000 suns.