Minimum Battery Energy Storage System Sizing Integrated with a Photovoltaic Plant Considering Practical Limitations

The integration of energy storage with intermittent renewable energy sources is seen as a critical step in the transition to a reliable and low carbon electrical energy supply. In particular, the utilization of battery energy storage systems (BESS) provides tremendous operational flexibility benefits. However, practical limitations of battery systems also need to be considered. This paper summarizes a study performed to determine the minimum battery size to support a photovoltaic (PV) system in various use cases when considering battery degradation and the practical limitations of a commercially available lithium ion battery. The results from the power model and detailed degradation estimate show that for a baseline 10-year useful life, the minimum size of a BESS is highly dependent on the DC:AC ratio of a PV system and the type of BESS services offered. The results from this paper are geared towards supporting planning studies into combined PV and BESS power systems.