Comparative Optical Analysis of Imprinted Nano‐, Micro‐ and Biotextures on Solar Glasses for Increased Energy Yield

Abstract

In modern photovoltaic (PV) systems such as bifacial and building‐integrated PV, a big share of sunlight impinges at large incident angles on the air‐to‐glass module interface. These designs exceedingly call for effective omnidirectional antireflective (AR) measures. Texturing of PV cover glasses can effectively mitigate reflection losses in a broad spectral and angular range. Numerous individual textures have been presented in the literature; however, the lack of consistent material stacks hinders a comparative evaluation. Herein, UV‐nanoimprint lithography is used to fabricate and analyze 12 different artificial and bioreplicated textures from nano‐ to mesoscale on glass. The angle‐resolved reflectance is examined for incident angles from 5° to 80° and analyzed the scattering properties. For example, the effect of the investigated textures on the annual energy yield is calculated for a tilted bifacial PV module located in Berlin, Germany. While well‐known moth‐eye nanostructures exhibit excellent AR behavior near‐normal incidence, their shallow angle performance is often not reported. The best‐performing textures exhibit features on microscale and a large surface enhancement factor, increasing the annual energy yield up to 5% when compared to nontextured devices. The results give clear design guidelines for textured glasses of future PV applications.