Grid-connected renewable energy systems are considered a viable solution for satisfying the swiftly growing demand. Nevertheless, the intermittent nature of renewable energy sources (RESs) hinders their performance and can not be efficiently utilized, rather imposes power quality and instability problem on the grid system. To alleviate this challenge, it is common practice to integrate RESs with efficient battery energy storage technologies. Lead-acid batteries were playing the leading role utilized as stationary energy storage systems. However, currently, there are other battery technologies like lithium-ion (Li-ion), which are used in stationary storage applications though there is uncertainty in its cost-effectiveness.
In this paper, a state-of-the-art simulation model and techno-economic analysis of Li-ion and lead-acid batteries integrated with Photovoltaic Grid-Connected System (PVGCS) were performed with consideration of real commercial load profiles and resource data. The Hybrid Optimization Model for Electric Renewables (HOMER) was used for the study of the techno-economic analysis. Besides, the performance of these batteries is greatly affected by the rate of charge and discharge cycling effects which gradually degrades the capacity of the battery. This effect was also investigated with Matlab using a simplified equivalent circuit model by considering a typical stationary application datasheet.
The techno-economic simulation output provided that the system with Li-ion battery resulted in a Levelized Cost of Energy (LCOE) of 0.32 €/kWh compared to the system with lead-acid battery with LCOE of 0.34 €/kWh. Besides, the Net Present Cost (NPC) of the system with Li-ion batteries is found to be €14399 compared to the system with the lead-acid battery resulted in an NPC of €15106. According to the result found, Li-ion batteries are techno-economically more viable than lead-acid batteries under the considered specifications and application profile.