Energy Storage for Mini Grids: Status and Projections of Battery Deployment

Mini grids, with approximately 21,000 installed globally, are emerging as a viable energy access solution. To reach half a billion people by 2030, the world requires 217,000 mini grids, largely solar powered with battery backup. Battery storage plays a critical role in mini grids, with lithium-ion batteries gaining popularity over traditional lead-acid batteries due to cost reductions, longer lifespan, and minimal maintenance requirements. This ESMAP report focuses on battery technologies in off-grid mini grids with a focus on trends in battery deployment and cost trends, as well as advantages and disadvantages of different battery types. Selecting battery technology for mini grid projects is a multifaceted decision based on factors, such as cycle life, depth of discharge, type of load, energy density, C-rating, thermal runaway, maintenance, after-sales service, hardware compatibility, maturity, cost, battery degradation, operating conditions, and environmental concerns. Mini grid energy storage recommendations include: studying battery performance in actual operating conditions; considering total cost, as well as upfront battery cost; adopting safety and performance standards; promoting recycling practices; encouraging the use of repurposed battery technologies; exempting mini grid batteries from import duties; providing technical skills training; and creating standard operating procedures to understand battery technology performance.