Power “smoothing” of a commercial-size photovoltaic system by an energy storage system

Photovoltaic power fluctuations caused by cloud transients can cause power quality and voltage regulation-related problems in distribution systems with high PV penetration. This paper describes such fluctuations in a commercial size concentrating photovoltaic (CPV) system, and evaluates the use of an energy storage system (ESS) for power smoothing purposes. Recorded ramp rates at both 1-minute and 1-second sampling intervals are used in the simulations. A simple moving average is applied to determine the power to be generated or absorbed by the ESS at each step. Simulations show that the 1-second sampling is more suitable for this particular PV system size, and the level of smoothing depends on the ESS size to invest in.