Analysis of Lead-Acid and Lithium-Ion Batteries as Energy Storage Technologies for the Grid-Connected Microgrid Using Dispatch Control Algorithm

A Microgrid consists renewable energy generators (REGs) along with energy storage in order to fulfill the load demand, even when the REGs are not available. The battery storage can meet the load demand reliably due to its fast response. The available technologies for the battery energy storage are lead-acid (LA) and lithium-ion (LI). The specific energy density of LI is higher than the LA battery and it has fast charge and discharge rate as compared to LA. However, a proper comparison of the performances of these two storage systems should be done in order to establish quantitatively the advantages either technology offers for a given application. In this study, a feasibility and comparative performance analysis of LA and LI based energy storage systems for grid-connected microgrid is carried out using NREL, SAM simulation tool. Grid-connected microgrid consists the solar photovoltaic (SPV) as the primary power generator. The excess energy produced by SPV is stored in the batteries. If there is excess PV electricity after charging batteries to maximum state of charge then excess electricity can be fed to the mains-grid. If both PV and battery powers are not sufficient to fulfill the demand then the deficit power can be taken from the grid. It is found that for a typical load the power fed to grid is more with LI based system as compared to the LA based system. The power imported from the grid is lesser with LI battery storage in comparison with LA storage. The results provide the feasibility and economic benefits of LI battery over the LA battery. The levelized cost of electricity are found to be ₹ 10.6 and ₹ 6.75 for LA and LI batteries respectively for energy storage application in the microgrid.