REopt Models Optimal Battery Dispatch Strategies for Sumitomo Electric

Sumitomo Electric’s utility-scale vanadium redox flow battery energy storage system. Photo by Dylan Cutler, NREL

NREL collaborated with Sumitomo Electric to provide research support in modeling and optimally dispatching a utility-scale vanadium redox flow battery (VRFB) energy storage system. The primary objective of the project was to optimize the dispatch of the VRFB system, using the REopt^® model to incorporate local grid support value and the value available in wholesale electric markets.

NREL worked with Sumitomo Electric and the local distribution utility to identify and monetize value streams derived from the application of utility-scale VRFB to local grid support use cases, including voltage regulation, capacity firming, and peak shaving. These value streams were incorporated into the REopt model along with wholesale market values such as participation in the energy ancillary services markets. In addition, NREL worked with Sumitomo Electric to accurately model all losses and auxiliary power consumption associated with the VRFB system. This VRFB performance model was incorporated into the REopt model for accurate assessment of cost-optimal dispatch.

REopt was used to perform day-ahead dispatch of the VFRB during a one-week operational test on a local host feeder based on California Independent System Operator (CAISO) day-ahead price signals and peak shaving requirements (based on forecasted feeder load).

Ongoing work with Sumitomo Electric is focused on evaluation of optimal dispatch of the VRFB in the day-ahead and real-time CAISO energy and ancillary services markets, and comparison of optimal participation with actual bidding results.

Sumitomo Electric is using this research to develop control strategies for the battery and define the business case for larger-scale deployment.