This report aims to improve the understanding of the key considerations and drivers of battery storage for renewables. It also aims to provide a timely update on market developments. Based on operational project case studies and a market analysis, the authors identify four applications in which batteries are deployed to increase the share of variable renewable energy and improve electricity supply reliability: (1) island systems and off-grid/rural electrification with renewable energy deployment, (2) households with solar photovoltaic, (3) variable renewable energy smoothing and energy supply shift and (4) fast, short-term electricity balancing in ancillary markets. According to the authors, the report demonstrates that islands and remote areas represent one of the most attractive opportunities for battery storage implementation in conjunction with variable renewable energy deployment.