Redox flow big battery tapped for Hokkaidō grid in Japan

A 17MW/51MWh redox flow big battery system is set to be installed in Hokkaidō, Japan, as part of a bid to expand and stabilise the grid on the nation’s northernmost main island, particularly as it adds more than 150MW of new wind power generation.

The energy storage system, which will have a capacity of 17MW for three hours, is being installed by Sumitomo Electric, after the company was awarded the contract for the job by Hakkaidō Electric Power Network.

HEPN – a transmission and distribution unit of Hokkaido Electric Power Co (HEPCO), the island’s monopoly electric company – launched a tender for grid-connected battery systems as part of its phase-one grid expansion plans, which include 15 new wind farm projects totalling 162MW.

Sumitomo’s flow battery storage system is being installed at HEPCO’s Minami-Hayakita Substation, in Abira Town, where it is expected to provide gird stabilising services from April 2022 to the end of March, 2043.

Sumitomo said it was selected following the completion of a successful three-year demonstration of a 15MW/60MWh version of the company’s redox flow battery system – a trial that was supported by Japan’s ministry of economy, trade and industry.

“I am truly delighted to be awarded this exciting program and also to be able to contribute to HEPN’s business,” said Hideo Hato, Sumitomo Electric’s senior managing director.

“Sumitomo Redox Flow Battery Systems have been operated stably and safely with the aim of ensuring grid stabilisation,” Hato said.

“With the long life and high safety, these systems will help boost the use of clean renewable energy sources.”

As Hato points out, redox flow battery systems differ from lithium-ion battery systems in that they are considered to be more robust, with no limitation on recharging cycles allowing stable operation for more than 20 years.

According to Hato, Sumitomo’s battery also allows for accurate monitoring of the state of charge, enabling stable operation continuously for an extended period of time without being affected by charge/discharge patterns.

Redox flow batteries are considered to be more environmentally friendly, due to the fact that their electrolytes, which do not deteriorate, can be used semi-permanently and also reused. And they are safer than their li-ion counterparts, with very low fire danger and the ability to operate safely in a broader range of temperatures.