“ You can't kill this battery” https://www.power-grid.com/energy-storage/you-cant-kill-this-battery-distributech-attendees-tour-san-diego-long-duration-storage-and-microgrid-project/
Excerpt
SDG&E said the six-year demonstration project showed the VRF battery can effectively be used in various ways, including the ability to adjust supply and demand as more renewable energy is adopted or improving the resilience of local power supply during extreme weather events. The 2MW/8MWh system powered 66 residential and commercial customers for close to five hours.
“We need storage that can sustain us not just for hours, but for days, and potentially weeks,” said Caroline Winn, CEO of SDG&E. “I think storage that can synchronize supply and demand over longer time horizons is really what’s needed.”
She added: “If we can figure out how to scale up flow batteries in a cost-effective manner, it has the potential to be a game-changer.”