Long-Duration Utility-Scale Energy Storage White Paper

Energy storage addresses a variety of short-term and long-term energy market needs and plays a vital role in enhancing energy reliability and dampening energy price volatility. This paper highlights leading energy storage applications—underground gas storage, pumped hydro energy storage, and battery energy storage (BES)—and practices in today’s gas and electric energy delivery systems, with a particular focus on the role and attributes of the long-duration energy storage market segment.

Underground gas storage supports both electric and gas systems, while pumped hydro and battery energy storage are employed exclusively for electric energy storage. In terms of cycle efficiency, gas underground storage systems are more efficient than battery electric or pumped hydro energy storage systems.

Both gas underground storage and pumped hydro can provide long-duration seasonal energy storage services with the capability of addressing seasonal variations in supply and demand (e.g., winter or summer peak space conditioning loads). Battery energy systems are mainly used for short-duration (<24 hour) grid services such as frequency or voltage regulation, onsite peak demand management, or supporting intraday renewable generation intermittency.

The need for robust and reliable energy storage across a range of scales, durations, and applications is fundamentally important for the energy systems today and the future. In the ongoing transition to a low-carbon integrated energy system, there is value in large-scale, long-duration energy storage currently provided by today’s gas storage systems with long-term potential for decarbonizing these systems.

View the Long-Duration Utility-Scale Energy Storage White Paper