US power utility San Diego Gas & Electric (SDGE) has begun testing a 2MW/8MWh vanadium redox flow battery (VRFB) in a microgrid to explore the technology’s capabilities at delivering grid-support services while increasing renewables penetration.
The project will serve as a proving ground for testing the battery’s microgrid capabilities and maximise its ability to support the grid with ancillary services, including voltage and frequency regulation.
The test comes two years after the VRFB— based at a PDGE substation— became the first battery of its kind to be connected to the California grid.
The system began participating in the California Independent System Operator’s (CAISO) wholesale electricity markets in 2019, and was used last summer to help minimise the impact of rotating outages during a heat wave.
SDG&E’s CEO Caroline Winn said: “Long-duration energy storage and microgrids are both key to helping California meet its clean energy, reliability and resiliency goals. We need breakthrough technologies to achieve 100% renewable energy on our grid and to power microgrids during emergencies.”
The initial demonstration project was launched in 2017 with the support of Japan’s New Energy and Industrial Technology Development Organization (NEDO) and the California Governor’s Office of Business and Economic Development (GO-Biz), SDGE and Sumitomo Electric (SEI).
The collaboration has been extended to run until December.
In 2015, NEDO signed an agreement with GO-Biz to test flow battery performance in a demonstration setting. NEDO then contracted with Sumitomo to implement the project.