Reliability based modeling of the performance of solar plants with multistate PV modules

Solar energy is widely used as a renewable energy source in the world. Photovoltaic modules are the main components of a photovoltaic system to generate the solar power from the solar radiation. The photovoltaic modules may have multistate working conditions and different performance levels depending on the solar radiation. Each component can be in different states, namely, complete failure, partial working, and perfect functioning. In this study, we present a model for solar power systems with PV modules having various levels of operational performance. We develop a reliability model for the system's power regarding the $m$ threshold value that is the minimum required total performance level for the system. This model reflects the performance levels of PV modules and working probabilities of modules. The problem is considered under different conditions regarding the dependency of two types of multistate PV modules. Two numerical examples are also conducted to evaluate the reliability and power generated by two solar plants located in two different regions. Beta and Weibull distributions are used for the numerical calculations to differ solar radiation regimes in the regions.