Аннотация:Calculations are made and energy parameters are compared for the actual operation data of three network photovoltaic power plants built in Russia by JSC Solar Systems. As the initial data for the calculations, the daily amounts of solar radiation and ambient temperature taken from the databases of NASA POWER, Meteonorm, and ERA5 have been used. The calculations have been carried out using a TRNSYS simulation environment, a specialized PVSyst engineering software package, and a HOMER Pro software package. In addition, we have used calculations based on a simplified technique including a linearized dependence of the photovoltaic module power on insolation and temperature implemented by means of Microsoft Excel. In all cases, we considered the efficiency of the network inverter depending on the transmitted power and the operating parameters of the module depending on the temperature. The results using each method have shown a good agreement with the actual output of photovoltaic power plants for the considered time periods. The best coincidence was observed for the case of TRNSYS, although the results vary depending on the source of the initial climatic data. Based on a simplified technique, an analysis performed concerning the output sensitivity with respect to the inverter efficiency factor and with respect to the temperature dependence of the power of photovoltaic modules showing that the method taking into account the ambient temperature makes a considerable contribution to the error of the results. The calculation results demonstrate that one could use engineering methods with a linear approximation of the photovoltaic module power depending on insolation and temperature in order to estimate the output of network power plants; however, of great importance is choosing the initial climatic data.