Long-Duration Energy Storage: An Industry Perspective

M. Perry
Largo Clean Energy,
United States


Grid-scale, battery-based energy storage systems (BESS) can play a critical role in transformation of the electric grid [1]. BESS with longer discharge durations can serve a broader range of applications, and are projected to become a large market [2]. For these long-duration energy-storage (LDES) applications, energy-storage systems with independent power and energy components have an inherent cost advantage [3]. Redox flow battery (RFB) systems have this enabling architecture and other unique attributes that make this battery architecture ideally suited for grid-scale LDES, such as: long cycle life even with deep cycles, inherently superior safety, and easy recyclability. Multi-MW-scale demonstrations of all-vanadium RFBs (VRFBs) have been successful completed and some systems have been in operation for > 10 years [4]. The primary commercialization challenge for VRFBs is capital cost (i.e., $/kWh installed). Therefore, this talk will focus on opportunities to further reduce the capital cost of RFB systems. Largo Clean Energy is a vertically-integrated developer of VRFBs, and LCE’s products are arguably the most advanced RFB product available on the market today. Some of the cost improvements that LCE has implemented will be described, as well as some future opportunities. 1. 2020 U.S. DOE Energy Storage Handbook | Energy Storage Systems (sandia.gov) 2. The Four Phases of Storage Deployment: A Framework for the Expanding Role of Storage in the U.S. Power System (nrel.gov) 3. R. Darling, et.al, “Pathways to low-cost electrochemical energy storage,” Energy Environ. Sci., 7, 3459 (2014). 4. T. Shigematsu, et.al, “The Development and Demonstration Status of Practical Flow Battery Systems,” Current Opinion in Electrochemistry, 18, 55 (2019).