Battery selection for optimal grid-outage resilient photovoltaic and battery systems

The first and most important purpose of the current research work is to investigate the effects that different battery types have on the optimal configuration of photovoltaic (PV) and battery systems, from both economic and resilience perspectives. Many industry reports, as well as research papers, have already highlighted the crucial role that storage systems have in the coming years in the electricity sector, especially when combined with renewable energy systems (RES). Given the high cost of storage technologies, there is an urgent need for optimizing such integrated energy systems. In this paper, a simulation-based method is adopted and improved, in order to compare different battery types based on their characteristics by considering projected trends in the future. After the introduction of four different battery types, i.e. lead-acid, sodium sulphur, vanadium redox and lithium-ion, the mathematical model for the optimization problem is presented, along with the required explanations. Subsequently, a case study is described and the numerical assumptions are defined. Therein, our specific focus addresses the different values that the four battery types possess in three critical parameters, i.e. battery cost, efficiency and depth of discharge (DoD). Finally, results and discussion are provided in an illustrative and informative way. This model provides a useful guide for relevant future work in the area, and also serves as a baseline for more comprehensive methodologies regarding optimal sizing of photovoltaic and battery systems.