Encapsulant for glass-glass PV modules for minimum optical losses: gas or EVA?

Because of the different spectral behavior of the two materials, a careful filtering of lamps used in solar simulators is mandatory due to the high-infrared content, in order to compare gas filled modules to EVA laminated ones. Low UV content in the incident spectrum underestimates the optical losses in the EVA module and high-infrared content overestimates the optical losses in the gas filled module. This analysis shows that the refractive index of SiN of industrial solar cells and the current spectral distribution of solar simulators defined according to the norm IEC 60904-9 could penalize gas filled modules in comparison to EVA laminated ones.