SPLTRAK Abstract Submission
 Spectral rear irradiance testing and modeling for degradation and performance of solar fields
Silvana Ovaitt, Matthew Brown, Chris Deline, Mike Kempe
National Renewable Energy Laboratory, Golden, CO, United States

This work investigates how the spectrum of irradiance incident on the rear of solar modules impacts their degradation and their performance in the case of bifacial PV. We calculate the spectral irradiance incident on the rear of modules through raytrace simulations and validate with measured field data collected from a 75kW single axis-tracked bifacial test site. An equation to calculate relative degradation is proposed, showing that current acceleration factors for UV damage in chambers can be off by +3% for the rear surfaces. Finally, a method for improving non-spectral simulations is proposed.