Energy storage is a rapidly growing field promising to revolutionize the way power is generated and delivered to end-users. Energy storage has the potential to support the evolution of the transmission grid. With increasing deployment of renewable power generation assets and the need for additional energy, an emerging opportunity for energy storage has been identified to provide frequency and voltage regulation, ancillary services, load shifting, and peak shaving at the transmission level. This report summarizes the capabilities and limitations of state-of-the-art energy storage technologies, operational transmission grid energy storage systems, and the challenges/caveats when considering developing different energy storage systems to act as transmission grid assets. The technologies – pumped hydro energy storage, compressed air energy storage, lithium ion batteries, flow batteries, and flywheels – are mapped to different transmission use cases based on their current functionalities. Opportunities for improvement, forecasted costs, and efficiencies are described to help illustrate the trends and motivations of the energy storage industry towards more cost competitive and effective systems.
Transmission Network, Virtual Transmission, Electrochemical Energy Storage, Mechanical Energy Storage, Energy Storage Use Cases, Reliability, Value Stacking