Optimizing the Size of Second-Life Batteries for Grid Storage Applications Using a Residual Load Tool

This study introduces a novel approach for sizing second-life battery storage systems in grid energy applications, utilizing a 15-minute residual load analysis tool developed in Microsoft Excel. The tool integrates a comprehensive database of generation and load profiles, accommodating various power ratings and weather conditions. Users can select specific generation and load profiles without power rating restrictions, enabling the calculation of key parameters such as duration of supply, duration of storage, charging or discharging state, total residual energy and maximum residual power (in both charging and discharging modes) as key parameters over different days within the selected year. These parameters are then compared with the characteristics of selected second-life battery storage systems on the market. Based on this comparison, the tool determines the optimal size of second-life batteries required to efficiently meet the residual energy needs during charging and discharging process in a day. This research provides a scalable and cost-effective solution for re-purposing second-life batteries, enhancing grid reliability and sustainability while promoting the integration of renewable energy sources. The findings offer practical guidance for stakeholders involved in energy storage system design, deployment, and the effective design of battery management system applications.