Reliability and Availability Analysis of Photovoltaic Systems

This paper introduces a novel simulation that combines the reliability modeling of photovoltaic (PV) system components with their respective I-V characteristic curves. The simulation encompasses varied system designs, including string inverter and module-integrated inverter concepts, and accounts for diverse solar irradiation and shading scenarios across multiple operating conditions. By integrating reliability aspects with real-world operating scenarios, the approach offers a holistic view of PV system performance considering the impact of frequency and occurrence of component failures and different repair strategies. The research delves deep into how the inverter reliability and the choice of repair strategies can influence the profitability of a PV system in various environmental conditions. A thorough statistical analysis revealed that both inverter lifetime and repair strategy have a significant effect on profitability. Key results indicate that in Germany, the optimal repair limit for the string inverter design is approximately at a 2.5 kWh daily power loss. In contrast, if the inverter lifetime in the module-inverter concept is sufficiently long, no repairs are necessary to achieve an optimal profit. These findings highlight the intricate relationship between inverter lifetime, application scenarios, and environmental conditions when determining optimal repair strategies.