Understanding Variability and Uncertainty of Photovoltaics for Integration with the Electric Power System

Data and analysis are needed to understand the variability of photovoltaic (PV) plants to avoid unnecessary barriers to the interconnection of PV. Several data sets show clouds can cause rapid changes in solar insolation. Smoothing of rapid ramps, however, occurs within PV plants. The degree of smoothing depends on plant size. Smoothing occurs on even longer time-scales between separate plants.