Declining power fluctuation velocity in large PV systems by optimal battery selection

Output power fluctuations are very important for photovoltaic (PV) systems. Where PV is connected into the grid, the rapid fluctuations would be detrimental to the performance of the power system to which the PV system is connected. Furthermore, rapid fluctuations of the output power of the PV systems make difficult prediction of their output power. As a result, planning for other generating units of the grid will encounter with trouble. In this paper, energy storage systems including batteries, which are the most common options for PV systems, have been analyzed to manage and to control output power rate of such systems. As power generation by PV systems is not a cost effective process, battery performance should be optimized as far as possible to prevent imposition of further costs caused by using batteries. In this paper, four common batteries have been compared in terms of cost and capability to decline their fluctuations and the most optimum option, which brings about the least costs, has been selected.