Is the VisBlue Battery Solution flammable?

We often receive this question, and it is a fair question, when discussing batteries. However, the comfort and safety of our customers are essential to VisBlue.

Our battery consists of a vanadium-based solution containing water and sulphuric acid. Most of the solution is water, which means that even in the events of short-circuiting, intense heat or high pressure, the battery is non-flammable. The battery will generate some amount of heat, but it will not exceed a level that is safe to touch.

Additionally, it should be mentioned that the VisBlue Battery Solution does not generate any gas. In the event of a leak, spillage will not cause toxic effect to the ambient atmosphere. However, the solution is a corrosive substance containing sulphuric acid and vanadium. It is therefore, inadvisable to get into contact with the fluid.


Most of the components in the VisBlue Battery Solution are made of different plastics and composites and are completely recyclable. The vanadium solution is non-degradable and will maintain its value throughout and beyond the life expectancy of the battery. This means that when the cell stack or the pumps in the battery have to be replaced after a certain number of years, the fluids can be reused in the same system or sold as raw material.

Where is VisBlue located?

VisBlue’s main office is located in Aarhus, Denmark, where we also have our production and development facilities. In Aarhus, VisBlue has close connections to the University of Aarhus, in order for us to continuously improve the chemical solution, the membrane and the bipolar plates.

Furthermore, VisBlue has a small office in Porto, Portugal, supporting the R&D and Business Development of VisBlue. With the office in Porto, VisBlue has a close relationship with the University of Porto.

henning der limer

Projects - what is VisBlue involved in?


Organic Redox Flow Battery Systems, or ORBATS as this project is called, is an ambitious project focused on optimising energy storage, both in costs as well as in efficiency and reduction of the impact that energy storage has on the environment.

With ORBATS we want to develop a redox flow battery technology that contains a non-toxic and non-corrosive organic fluid with a simpler, soluble electrolyte component. Together with Vestas, Aarhus University, DTU Energy, Harvard University and Lithium Balance, VisBlue has embarked on a project with the scope of creating solutions for this.

However, the technology is still on the R&D level, which means that it will take a few years before it will be commercially available.

Click here to see more projects

Is the VisBlue Battery Solution commercially available?

Yes, it absolutely is. In 2018, we had our first commercial sale which we installed in June the same year. Since then, we have installed more batteries around Denmark and Europa with more on the way.

VisBlue was founded in 2014 and in the first few years, we have been biding our time and mainly been participating in projects, developing a commercially available product as well as developing relationships with our stakeholders. The projects have been our field work and real-life experiences, where the good ideas have been scaled up to applicable standards.

The cost?

Each requirement for energy storage is different and the solution is therefore tailored to the customer.

We are happy to discuss individual requirements to see if we have a solution that is appropriate for you. With larger storage requirements, the VisBlue Battery Solution becomes cheaper per kWh.


The batteries are designed to last for more than 20 years.

Vanadium-based energy storage systems can theoretically last forever.

The active component - vanadium - is a rechargeable electrolyte that never wears out. This is because of the type of chemical reaction that is occuring in the process. The electronics and software that control the system can be upgraded, just like a computer. The last major component - the plastic tanks that contain the electrolyte - last for decades.

visblue battery