Blue Battery: storage in water and table salt

  • Module
  • Off-grid
  • Storage
  • Energy storage
  • Affordability
  • Durability

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AquaBattery B.V.

Published 06 Feb 2017

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Blue Battery: storage in water and table salt

Our solution, the Blue Battery, is a battery that runs purely on water and table salt (Sodium Chloride), by storing electricity in a concentration difference between fresh and salty water. With the help of two technologies, ED and RED, this all works. During the ED-process, electricity is stored by pumping two streams of water through a stack of membranes, thereby increasing the concentration difference between the two streams. The electricity can be obtained back by pumping these two streams back through the stack, allowing the powering of houses. The Blue Battery can be used to facilitate the growth of renewable energy sources such as solar and wind power. The transition toward these sources is accelerating. However, the sources possess an intermittent character: the sun does not shine on every moment of the day unfortunately. At the moment fossil-fired power plants are still necessary to deal with these fluctuations. Hence, in order to facilitate this transition fully, energy storage is key. Conventional storage technologies, like Lithium-ion and lead-acid batteries, are not designed for storing vast quantities of electricity as power- and storage capacity are coupled, making storage unnecessary expensive. The Blue Battery allows to store electricity in a safe, scalable and environmentally-friendly way: by making the water tanks bigger, one simply stores more energy. As water and table salt are highly abundant and cheap materials, storage is consequently affordable!

How it benefits society

Most growth in renewable energy technologies is experienced in solar and wind energy. Energy supply from such technologies is intermittent. They often deliver electricity at the wrong timing. If this energy is not consumed nor stored, it will be lost. In fact, this problem makes these energy technologies less sufficient than they are supposed to be. Furthermore, with increasing supply of energy from renewables, and penetrations of these renewable technologies exceeding ~20%, the electric power grid needs to deal with the fundamental problem of unstable and intermittent supply, causing the grid to become unstable and which may subsequently lead to power outages. Hence, the grid requires flexibility in electricity demand and especially a sufficient amount of energy storage on the scale of hours up to one week. No electricity storage systems are available yet that can be available and embeddable locally. Conventional battery technology is not designed for this and consequently not economically viable. The Blue Battery, thanks to its scalability, provides an affordable alternative for storing vast quantities of electricity. Together with a diverse team of partners, such as two large Dutch grid operators, electrical, construction and IT-companies, technical universities and FujiFilm, we are now building the first pilot with a capacity of 10 kWh, with the goal to scale to MWh storage in 2019.

Who we are


AquaBattery B.V.
Emil Goosen, Jan Post, Jiajun Cen
Delft, the Netherlands

We are a team composed of young high potential graduates and passionate academic and industrial captains of sustainable technologies. We are dedicated to help our society to make the transition towards renewable energy technologies, as a preventive measure of climate change. We discovered that the bottleneck lies in energy storage, as energy production from solar or wind is intermittent. With this clear challenge in mind, we have developed the world’s first sustainable battery and we are very excited to realise our vision with this product. Our motivation comes from the inside, as we believe that we need to give back for what we consume, or at least to balance that out. Together with our team we want to foster the growth of renewables and reduce the electricity bills of consumers! Our team started collaborating in 2014, with two members of our team who just finished their PhDs back then, and four students, who are now all graduated, and two of them continued with a PhD (Imperial College and Wageningen University, both on the core technology). The team possesses a diverse set of skills, with work experience in (project)management, science and also in the renewable energy engineering sector; two of our members have also started businesses before. For more information, visit:

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