Setup for Long-Term Outdoor Testing of Optically Modified PV Modules Regarding their Thermal and Electrical Behavior Under Load

Abstract

Optical modifications of the light-facing side of photovoltaic (PV) modules can be used to increase their efficiency by implementing anti-reflective or anti-soiling properties or by achieving a reduction of the operating temperature. Furthermore, such front-optical modifications can be utilized to hybridize concentrating solar thermal systems and PV systems. In order to characterize such modifications correctly, special attention has to be paid to two points: the modules have to be operated under load to keep the cells at a realistic operating temperature, and high precision of the temperature measurement is required to quantify the potentially very small effects of the modifications (e.g., for radiative cooling decreases in operating temperature of less than 1 K have to be expected). In this paper, a setup is presented for testing front-optical modifications in fixed tilt configuration in Almería, Spain. The loading is achieved by the use of an electronic load and the precision of the temperature measurement is achieved by Platinum resistance temperature detectors (Pt100s) laminated into the modules in combination with high precision multimeters. To demonstrate the capabilities of the setup, exemplary measurement data is shown.