Small-volume fabrication of a 144-cell assembly for high-concentrating photovoltaic receivers

Concentrating photovoltaic (CPV) is a solution that is gaining attention worldwide as a potential global player in the future energy market. Despite the impressive development in terms of CPV cell efficiency recorded in the last few years, a lack of information on the module's manufacturing is still registered among the documents available in literature. This work describes the challenges faced to fabricate a densely packed cell assembly for 500× CPV applications. The reasons behind the choice of components, materials, and processes are highlighted, and all the solutions applied to overtake the problems experienced after the prototype's production are reported. This article explains all the stages required to achieve a successful fabrication, proven by the results of quality tests and experimental investigations conducted on the prototype. The reliability of the components and the interconnectors is successfully assessed through standard mechanical destructive tests, and an indoor characterization is conducted to investigate the electrical performance. The fabricated cell assembly shows a fill factor as high as 84%, which proves the low series resistance and the lack of mismatches. The outputs are compared with those of commercial assemblies. A cost breakdown is reported and commented: a cost of 0.79/Wp has been required to fabricate each of the cell assembly described in this paper. This value has been found to be positively affected by the economy of scale: a larger number of assemblies produced would have reduced it by 17%.