Smoothing of photovoltaic power generation using batteries as energy storage

The intermittent nature of renewable energy sources originates technical challenges for the integration of renewable generation plants to the existing power grid. Using energy storage devices is an option to solve these problems. In this paper, a study of energy storage using batteries with photovoltaic (PV) generation is presented. Models of a PV array and battery were implemented and validated, and then used to perform power smoothing of the PV array power output by means of a smooth power reference obtained with a filter. The goal is to reduce unwanted power variations originated from the energy source variability. Different limits of State of Charge (SOC) were imposed to the battery, in order to observe its response and capability of smoothing power variations. Real irradiance and temperature profiles measured by a weather station were used to calculate the PV array power output.