BAoBaB project - Sustainable energy storage using salt and water


By Michele Tedesco, Wetsus, European Centre of Excellence for Sustainable Water Technology, The Netherlands

Winter 2020

The need of energy storage for our society has drastically increased in the last years, due to a growing share of renewables (wind and solar) on electricity grids.

Electrochemical energy storage has received increasing attention as an alternative storage system, and several battery technologies have been making rapid advances in the past years. However, despite all the R&D efforts, a new generation of innovative batteries is urgently needed, to provide safe and sustainable energy storage on large scale and ensure grid stability in the future.

The aim of the BAoBaB project is to develop and demonstrate the first acid-base flow battery as a safe and environmentally friendly technology for centralized and decentralized energy storage. The technology is based on bipolar electrodialysis, i.e. a membrane process able to dissociate water and generate acid and base solutions. During the battery charge, electricity is used to generate acid and base from a salt solution. During discharge, the opposite process occurs, and electric energy can be harvested by the controlled mixing of acid and base in the battery. As a result, the acid-base flow battery technology allows to store electric energy using only salt and water, thus providing a safe and sustainable energy storage system. The technology has already been demonstrated at laboratory scale, and the first demonstration at pilot scale is currently ongoing.


  • Bring to the market a scalable and flexible energy storage system at kWh-MWh scale
  • Enlarge the portfolio of available energy storage systems for centralized and decentralized applications (e.g. island grids)

The BAoBaB project is a H2020 collaborative project gathering 6 partners from 3 different EU countries. In the past four years, the BAoBaB partners have being focusing their R&D efforts on several aspects, including development of novel battery components (monopolar/ bipolar membranes), process modeling, life cycle assessment, battery optimization at laboratory scale, stack design and scale up.

The final goal of the BAoBaB project is to demonstrate the acid-base flow battery technology in relevant environment (TRL 5-6). Last months a first pilot-scale demonstration plant with a target capacity of 1 kW/7 kWh has been built by AquaBattery. The pilot has been recently installed in Pantelleria (a small Italian island in the Mediterranean Sea), and will be tested in the upcoming months as energy storage system at the local power plant, to provide seasonal storage during high energy demand in summer months. An important milestone in the scale-up of the technology, and in the path towards sustainable energy storage.


Contact Information
Project Coordinator: Dr. Michele Tedesco, Wetsus

Project partners: Wetsus, AquaBattery BV, Fujifi lm Manufacturing Europe BV, Universitá degli Studi di Palermo, Fundación CIRCE, SMEDE SpA.

The BAoBaB project has received funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement no. 731187.