Survey on Current Large-Scale Energy Storage Systems.

The frequency of natural and other disasters is becoming more frequent and destructive. This is leading countries to evaluate and harden their existing infrastructure. When it comes to the electrical infrastructure, diversifying the energy generation sources will enable a resilient electric power system. The diversification is coming from many renewable energy sources that are clean, abundant, and cost-effective in decentralizing the legacy electrical distribution system. However, due to their intermittency and sometime unpredictable generation time and capacity, i.e., excess generation at times when the demand is low, large-scale storage energy options must be considered. This paper provides a brief survey of some of the recent storage technologies in operation and/or being developed and highlights the efficiency, prerequisites, and optimal scenarios for the deployment of such technologies into the generation and storage mix. Specifically, the paper discusses the following large-scale energy storage technologies: Pumped Storage Hydropower; Thermal Energy Storage; Power-to-Gas storage; Compressed Air Energy Storage; Flywheels, Supercapacitors, and electrochemical energy storage (battery storage). The paper emphasis is on the recent advances and projects in using battery storage and looks at the penetration of this storage in the United States and Germany.