Analysis and Identification of Measurement Uncertainty Sources of a LED Sun Simulator with Double-Side Illumination for Bifacial PV Module Power Rating

This paper gives an understanding of measurement uncertainty sources of LED sun simulators beyond uncertainty calculation for pulsed Xenon lamp systems. Technology-specific uncertainty sources will be identified, and an uncertainty budget calculation of a single-side and a double-side LED solar simulator will be presented. Results show significant differences between the two light sources. The expanded uncertainty (k=2) for power measurements at 1000 W/m
²
(front) and 200 W/m
²
(rear) is ±8.4%. Due to the 648 individual powered LED channels of each light source, the spectral distribution, the spatial non-uniformity, and the light stability during the I-V sweep are some of the main contributors to the expanded uncertainty.