A microtracking concentrator photovoltaics (CPV) module with a bi-convex aspheric lens array was designed, and its performance was numerically and experimentally verified. The lens shape was optimized considering the yearly incidence characteristics of direct solar radiation. The lens optimized at 127 × was found to converge 68.7% of the yearly cumulative direct solar radiation to solar cells and to be robust against changes in installation azimuth and tilt angles. The incidence-angle characteristics of a prototype lens agreed well with the design analysis. In an outdoor test using a prototype microtracking CPV module with an optimized lens and a triple-junction solar cell, the power generation was 1.32 times higher than that of the 17%-efficient Si cell and nearly 30% module conversion efficiency was achieved under clear sky conditions.

Two types of highly transparent concentrator photovoltaic (CPV) modules that separately utilize direct sunlight and diffuse sunlight for efficient dual‐land‐use applications were designed and tested. The type A module, comprising a typical‐scale CPV lens and solar cells, has a completely direct‐diffuse‐separated design for power generation and other solar applications. On the other hand, the type B module, consisting of a microscale CPV lens and solar cells, was designed to increase the amount of direct sunlight transmitted based on an intentional reduction in the ratio of the lens aperture area to the module aperture area. In experiments, both modules exhibit higher electricity yields and module‐transmitted irradiances (MTIs) than those of a conventional partially transparent flat photovoltaic module with 17% efficiency Si solar cells. Furthermore, the modules show direct normal irradiance‐based efficiencies of 26.7% (type A) and 18.5% (type B) while simultaneously showing MTI‐to‐global normal irradiance ratios of 15.3%‐63.7% (type A) and 38.0%‐63.8% (type B) under various irradiance conditions. Thus, an irradiance of at least 160 W/m² under the modules can be achieved even when they are arrayed without gaps (at a ground coverage ratio = 1).

Stretchable photovoltaics are emerging power sources for collapsible electronics, biomedical devices, and buildings and vehicles with curved surfaces. Development of stretchable photovoltaics are crucial to achieve rapid growth of the future photovoltaic market. However, owing to their rigidity, existing thin-film solar cells based predominantly on silicon, compound semiconductors, and perovskites are difficult to apply to 3D curved surfaces, which are potential real-world candidates. Herein, we present a stretchable micro-scale concentrator photovoltaic module with a geometrical concentration ratio of 3.5×. When perfectly fitted on a 3D curved surface with a sharp curvature, the prototype module achieves an outdoor power conversion efficiency of 15.4% and the daily generated electricity yield improves to a maximum of 190% relative to a non-concentration stretchable photovoltaic module. Thus, this module design enables high areal coverage on 3D curved surfaces, while generating a higher electricity yield in a limited installation area.