Evaluating the Possibility of Increasing the Capacity Factor of Grid-Connected Photovoltaic Power Plants

The influence of two methods for increasing the amount of solar radiation incident on the solar power plant (SPP) photovoltaic array surface—the use of Sun tracking systems (trackers) and bifacial photovoltaic modules—on the capacity factor (CF) value is estimated for the entire territory of Russia. The CF values are estimated for a few types of photovoltaic modules under the climatic conditions of Russia by means of dynamic simulation in the TRNSYS code. The actinometric and climatic data from the NASA POWER long-term satellite observations database with the 1° × 1° latitude-longitude spatial resolution were used. The photovoltaic modules were described by a five-parametric model, the parameters of which were determined from the module passport data provided by manufacturers. Electricity outputs and CF values were compared for SPPs equipped with vertical-axis and tilted-axis trackers and SPPs equipped with fixed south-oriented photovoltaic modules at different tilt angles. It has been determined that the maximal effect of trackers use can be achieved in the arctic zone of Russia, where the amount of electricity generated by an SPP can be increased by 70–80%. In certain southern regions of the country, the amount of electricity generated in the case of using trackers can be increased by as much as 55%. It is shown that the best effect is obtained in the case of using fixed bifacial modules or bifacial modules equipped with tilt-axis trackers (the increase of CF is up to 4% abs.). By using vertically oriented bifacial modules, the CF value can be increased to some extent in high latitudes. In moving toward lower latitudes, the gain in the CF by using the module rear side decreases until it becomes fully compensated by the loss resulting of their nonoptimal orientation.