A theoretical analysis of the electric power storage capacity under changing renewable energy supplies and power demands

Electric power from renewable energy sources may cause unstable situation to power grid, because of its electric power fluctuation. In order to smooth the power fluctuation from the renewable energies, there are some researches to simulate the watt-hour capacity of the power storage systems based on the survey data of renewable energy outputs. However, the results only show in limited situation. In a micro-grid, its power load receives both fluctuation of supplies from the renewable energies and demands. It is important to compute the theoretical storage capacity consider both the renewable energies and demands. The aim is to determine the numerical values of the power storage capacity when examining the micro-grid power system; and to explain analytically how capacities computed. In this paper, a mathematical model of power storage capacity has been modeled using the efficiency of power storage, the maximum and average output of micro-grid, and the range of smoothing.