Experimental determination of Arrhenius degradation coefficients for monocrystalline photovoltaic solar cells

Abstract

As photovoltaic solar technology plays a pivotal role in the transition to renewable energy, concerns about long-term performance still persist. This research aims to investigate and model the ageing effects in photovoltaic solar cells, defining power and voltage degradation coefficients. Monocrystalline modules from two different manufactures are tested. The objective is to provide quantitative insights into performance decline over time, offering guidance for improving photovoltaic system reliability. Photovoltaic solar cells are subjected to accelerated ageing tests considering high temperature conditions to increase electron collisions, emulating long-term operation. It is verified that open-circuit and maximum power point present a logarithm decline trend over time. On the other hand, the accelerated temperature ageing tests allow us to apply the Arrhenius model, which also represents logarithm behaviour but with the temperature. This is used to predict real-world degradation trends. Results showed that maximum power output declines between 0.22% and 0.80% per year, depending on the manufacturer. Moreover, the $V_{oc}$ presents a faster degradation rate, decreasing 10% in approximately 4 years. The model results present high coefficients of determination, confirming the strong correlation between empirical data and theoretical models.