Influence of Photovoltaic Module Degradation on Photovoltaic Power Plant Investment Payback Time

This paper presents a methodology for assessing the impact of photovoltaic (PV) module degradation on the payback time of PV power plant investment in a prosumer power system. The methodology uses PV module performance measurements to determine the current degradation level and compares it to the manufacturer-defined degradation level during its lifetime. This represents input data for the PV power plant simulation model, which determines its performance during its lifetime and the investment payback time. The proposed methodology is evaluated using experimental measurements of the performance of two 10-year-old PV modules from the commercially most widely used technologies. The performance measurements on PV modules indicate that the current degradation level does not align with the manufacturer’s defined one. Equal-size models of PV power plants are created in PVSOL Premium software to analyze the impact of manufacturer-defined and real-life degradation on the payback time of PV power plant investments. The simulations confirmed that this influences the payback time of investments, emphasizing the importance of choosing a high-quality PV module during planning and installation.