Optimization of advanced energy storage for solar-diesel hybrid microgrids

Hybrid solar / diesel / battery microgrids are being suggested as a solution to rural electrification for many developing countries, even those with existing transmission / distribution networks. One question is how to balance the sizing of the various subsystems. Energy from photovoltaic systems is now far cheaper than even the lowest fuel-only costs for diesel generators. However, solar is only available during the day and is often intermittent, so energy storage is needed to optimize microgrid system performance and economics. With high penetrations of PV, the role of storage has moved from supplying overnight load to the need to capture excess PV energy during the day when load is low. This paper uses a custom time-series model to discuss optimization of solar, energy storage and on-demand-generators for community scale applications ranging from 10 kW to 10 MW of load. The paper also discusses the requirements for energy storage technologies needed to meet this application.