Variability of Power Generation in Small Photovoltaic Installations

Photovoltaic (PV) installations convert the energy of optical radiation into electrical energy. The power of optical radiation reaching the Earth’s surface varies. Therefore, the electricity produced by photovoltaic installations also changes. Some of the changes are deterministic (annual and daily changes in the position of the Sun) and the rest are stochastic (obscuring by clouds, vegetation, birds, planes, etc.). The variability of optical radiation causes unpredictable changes in the generated power that is fed into the power grid. The paper describes examples of variability of power generated in small photovoltaic installations located in Poznan. The upper limit of power variability has been determined and compared with the measurement results.