Clasing, Lionel: Experimental Assessment of Nanoimprinted Textured Frontsheets for PV Modules

Abstract in English:

Textured frontsheets can significantly reduce the optical losses of PV modules at high angles of incidence. These frontsheets can potentially be used in building-integrated PV applications like façades or roofs with suboptimal orientation in order to improve electrical energy yields and cost-effectiveness. In this work an experimental assessment of nanoimprinted micro-textures on PV single-cell laminates is done to quantify reduced angular-dependent optical losses in detail. PV single-cell laminates under test with size of 180 mm x 180 mm and nanoimprinted textures on 3 mm thick soda-lime-silicate float glass and 0.125 mm thick polyethylene terephthalate substrates. The textures are composed of periodically arranged pyramids with heights of 30 µm and a base area of 50 x 50 µm. The gain in relative transmission of the textured samples compared to the non-textured samples on PET film substrate is 12.1 % at 70°, 22.0 % at 75°, 42.2 % at 80° and 91.6 % at 85°. In comparison, the gain of textured flat glass samples shows 7.9 %, 19.2 %, 13.7 % and 69.7 % at 70°, 75°, 80° and 85°, respectively. The results give clear indications that the textured frontsheets have a significant effect on the angle-dependent losses of PV modules.