High frequency outdoor measurements of photovoltaic modules using an innovative measurement set-up

摘要

This article presents transient temperature results obtained using an innovative outdoor measurement set-up for photovoltaic modules at the KU Leuven campus Gent. This set-up is fast, flexible, modular and accurate through the use of National Instruments LabVIEW software and a CompactRIO with multiple C-series modules for the measurement of weather parameters from sensors such as irradiance, temperature, wind speed and direction. Temperature measurements performed using this set-up on multiple photovoltaic modules in a flat-roof mounting with open back show a variation of the temperature of the cell and the backsheet which is larger than often assumed. These temperature variations are primarily related to the irradiance, with wind speed and direction playing a secondary role. A temperature sensor mounting method is presented which leads to improved photovoltaic module thermal response reporting, with the added benefit that it is repeatable, easy to implement and more accurate in variable weather conditions.