With regard to the off-grid operation, the energy storage system has considerable importance in the microgrid. The ESS mainly provides frequency regulation, backup power and resilience features.
Microgrids are small-scale energy systems with distributed energy resources, such as generators and storage systems, and controllable loads forming an electrical entity within defined electrical limits. These systems can be deployed in either low voltage or high voltage and can operate independently of the main grid if necessary .
Abstract: This paper presents the updated status of energy storage (ES) technologies, and their technical and economical characteristics, so that, the best technology can be selected either for grid-connected or off-grid power system applications.
As discussed in the earlier sections, some features are preferred when deploying energy storage systems in microgrids. These include energy density, power density, lifespan, safety, commercial availability, and financial/ technical feasibility. Lead-acid batteries have lower energy and power densities than other electrochemical devices.
Energy sources that comprise the microgrid include technologies such as diesel generators, fuel cells, PV panels, and wind turbines associated with storage resources. Energy storage technologies play a key role in the operation of the system.
While mentions of large tied-grid energy storage technologies will be made, this chapter focuses on off-grid storage systems in the perspective of rural and island electrification, which means in the context of providing energy services in remote areas. The electrical load of power systems varies significantly with both location and time.