Energy giant Statkraft to trial “revolutionary” flow battery made with saltwater

Norwegian renewable energy company Statkraft has announced a partnership with Dutch company Aquabattery to develop a pilot test of its innovative saltwater-based flow battery designed to improve long-term storage.

Aquabattery, which was formed in 2014 by five engineers, has developed a flow battery that uses only table salt and water.

The Aquabattery is described as “an acid-base flow battery based on reversible water dissociation” and stores electricity in the form of chemical energy in acid, base, and saltwater solutions kept in separate tanks.

Its promotors say it is  cost-efficient long duration energy storage (LDES) device, and capable of storing energy from 8 hours up to multiple days or weeks.

When paired with renewable energy generation such as solar or wind, electricity is used to convert the sale into two safe chemical solutions, or electrolytes, that can be converted back to salt water when green power is needed again.

The energy market is focusing attention on the prospects of flow batteries as a solution to long term storage, particularly with the difficulties facing pumped hydro storage. Other flow battery developers use different electrolytes such as vanadium or iron.

Announced on Tuesday on the sidelines of the COP28 climate conference in the UAE, Aquabattery and Statkraft says they will built a pilot facility to test the technology in Delft, in the Netherlands over a period of six to 12 months.

“Aquabattery’s new technology is promising. It has the potential to accelerate and revolutionise the development of long duration energy storage,” said Christian Rynning-Tønnesen, Statkraft CEO.

“Without the right mix of energy storage in the system, we risk slowing the pace of wind and solar rollout, and consequently the green transition.

“As the world needs to triple up in renewables, succeeding with long duration energy storage is one of many bits needed in the puzzle to actually make that happen.”