Degradation of micromorphous thin-film silicon ($\alpha$-Si/$\mu c$-Si) solar modules: Evaluation of seasonal efficiency based on the data of monitoring

A method for assessing the efficiency of $\alpha$-Si/$\mu c$-Si solar modules is developed; the method is based on monitoring current and voltage at the point of highest voltage and on measuring the temperature at the surface of the module. The technique for assessment of the parameters of the $\alpha$-Si/$\mu c$-Si modules in the course of their operation after initial degradation of the module is described; the results of parameter evaluation are compared with the values measured in the laboratory. The error in evaluating parameters was no larger than 3%; this error amounted to 0.36% in the case of estimating the parameters under standard conditions and maximal power of the module. This method can be used for evaluating a module’s efficiency and for short-term prediction (day, week) of the power generated by a solar power plant under conditions of operation using standard tools for monitoring.