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Title: Snohomish Public Utility District MESA 2: An Assessment of Flow Battery Energy Storage System Technical Performance

Technical Report ·
DOI:https://doi.org/10.2172/1545342· OSTI ID:1545342

This report investigates the technical performance of the 2.2 MW, 8 MWh MESA 2 advanced vanadium flow battery energy storage system (FBESS), consisting of four 0.55 MW, 2 MWh strings, based on a number of baseline and use case tests. The FBESS is located at the Everett, Washington substation and owned by SnoPUD. The FBESS was procured by SnoPUD with matching funds by the Washington Clean Energy. Baseline tests were intended to assess the general technical capability of the FBESS (e.g., stored energy capacity, ramp rate performance, ability to track varying charge/discharge commands, direct current (DC) battery internal resistance). Use case tests were used to examine the performance of the FBESS while engaged in specific grid services (e.g., arbitrage, power factor correction). The project measured and/or calculated parameters that are important for understanding FBESS performance when subjected to actual field operation for achieving economic benefits, e.g., round trip efficiency (RTE) with and without rest, with and without auxiliary loads, auxiliary power consumption, signal command tracking, temperature trends during operation, parasitic power loss unaccounted by auxiliary load during rest, and state of charge (SOC) excursions. These baseline and use case parameters were analyzed using recorded test results. In addition, the results and lessons presented herein are also beneficial for any task or effort that needs technical assessment on similar and different types of FBESS based on technical specifications and/or field deployment results, since the assessment methodology remains the same.

Research Organization:
Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC05-76RL01830
OSTI ID:
1545342
Report Number(s):
PNNL-28478
Country of Publication:
United States
Language:
English