Performance of Photovoltaic Modules After an Accelerated Thermal Cycling Degradation Test

Abstract

Typically, datasheets of photovoltaic (PV) modules state that the guaranteed power production remains constant for a certain period of time and after this point, a linear reduction begins reaching an estimated 80% of the original rated power. Moreover, literature reports that the degradation of PV modules reaches less than 1% per year. In this regard, after 20 years of operation a typical PV module will deliver approximately 20% less energy than a the beginning of its life. In this article, the results of an accelerated thermal cycling degradation test are compared to its brand new conditions. These results demonstrate that although the performance among the PV modules is variable when new, after the cycling test the performance of the degraded PV modules is similar. In this case, the power reduction of the degraded module varies from 1.4% up o 7.6% when compared to the initial condition. Furthermore, an Electrochemical Impedance Spectroscopy (EIS) analysis demonstrates that at high frequencies the results are practically the same regardless if the panel is new or degraded, but at low frequencies the variation of the impedance is notorious.

Sistema de refrigeración geotérmico para la mejora de la eficiencia de paneles solares fotovoltaicos

“…Esto evita que su temperatura caiga drásticamente en las noches frías (comparado con el panel estándar) o que alcance temperaturas extremadamente altas durante el día. Se espera que un menor estrés térmico pueda tener una influencia positiva en la durabilidad de los paneles [22]. Durante la campaña de ensayos, las temperaturas máxima y mínima medidas en el panel refrigerado fueron de 39.4 ± 0.5 °C y 4 ± 0.5 °C respectivamente, mientras que en el panel estándar fueron 50.7 ± 0.5 °C y 0.5 ± 0.5 °C.…”