Idemitsu plans 864 MWh vanadium flow battery at Australian coal mine site

The Australian arm of Japanese energy company Idemitsu Kosan is proposing to develop a grid-scale vanadium flow battery as part of a clean energy precinct being advanced at a former coal mine in Muswellbrook, New South Wales.

The flow battery project, planned for the 2022-decommissioned Muswellbrook Coal Mine, will have a storage capacity of at least 108 MW/864 MWh, with up to 200 MW of bidirectional inverter capacity installed to allow for the battery energy storage system to charge or discharge for shorter periods of time where market conditions allow. The project will connect to the grid via Ausgrid’s 132 kV Sandy Creek substation.

Idemitsu said the project will use vanadium redox flow battery technology, noting it offers several advantages over lithium-ion batteries, including “use of a safe and stable non-flammable electrolyte, negligible battery degradation over 30 years, and flexible storage duration with potential to increase capacity by adding electrolyte to extend storage time.”

“Vanadium redox flow batteries are an Australian invention, born at the UNSW in 1984, that provide safe, true long-duration storage that is 99% reusable or recyclable at the end of 30 plus years of project life,” the company said.

Idemitsu said the use of vanadium flow technology represents a “catalyst project” that will support Australian manufacturing and demonstrate the technology’s readiness for the broader market adoption. It added that vanadium electrolyte used in the battery will be manufactured in Australia, and opportunities to bring battery manufacturing to Australia will be explored.

While the project is in early stage development, Idemitsu expects construction of the project to begin in early 2028 with the build phase to take about two years.

The vanadium flow battery project forms part of Idemitsu’s plan to repurpose the Muswellbrook coal mine site into a renewable energy precinct that will incorporate solar and pumped hydro, while investigations are continuing into developing green hydrogen facilities on-site.

Idemitsu is working with Swedish renewable energy developer OX2 which has commenced construction of a 135 MW solar farm and 135 MW/270 MWh battery project at the site. It is also collaborating with energy generator and retailer AGL to build a 400 MW pumped hydro project that would also use the mine site and would provide up to eight hours of energy storage.

Idemitsu said the Muswellbrook Clean Industries Precinct demonstrates how legacy mining assets can be repurposed to support long-duration energy storage, regional jobs and future industry.

From pv magazine Australia