Effect of secondary lens concentrators on the output parameters of solar modules with cascade photovoltaic converters

The feasibility of increasing the concentration ratio and expanding the misorientation curve using secondary lens elements is considered for solar modules with triple-junction InGaP/GaAs/Ge photovoltaic converters and radiation-concentrating Fresnel lenses. Composite glass-silicone Fresnel lenses measuring 40 × 40 and 60 × 60 mm (plan view) with focal lengths of 70 and 110 mm, respectively, are used as primary concentrators. The focal length of secondary plane-convex glass lenses is varied from 5 to 25 mm. With the shortest-focal-length secondary lenses used, measurements of the parameters of the photovoltaic converter in a system with radiation concentrators that were made with a pulsed solar tester show the increase in the concentration ratio and the expansion of the misorientation curve by a factor of 2.5–3.0. The parameters of test modules with lens panels measured under solar illumination are found to be in good agreement with laboratory data.