ORBATS Organic Redox Flow Battery Systems

Denmark and many other countries around the world aim to increase the share of renewables in their energy system significantly.

For this to happen, a significant challenge has to be addressed: Solar and wind are fluctuating sources that cannot be controlled at will as traditional power plants can.

This challenge will increase as the share of wind and solar in the energy system increases.

This trend will cause increased demand for safe, inexpensive, large-scale stationary energy storage. The ORBATS project will meet this challenge by developing cheap and scalable storage solutions.

ORBATS is a collaboration between DTU Energy, Vestas, VisBlue, Aarhus Universitet, Lithium Balance and Harvard University. It is supported financially by Innovation Fund Denmark.

Traditional batteries, as used in cell phones and other electronic devices, consist of relatively expensive solid materials that store the energy.

This means that when you need to store twice the amount of electricity, the battery has to be twice as large. To avoid this physical limitation, ORBATS will develop so-called flow batteries where the energy is stored in a liquid outside the battery itself.

If you need more capacity, you can simply get a larger storage tank and use more liquid without otherwise increasing the size of the battery. Flow batteries are well suited for energy storage and can be used as back-up in smaller installations instead of Diesel generators.

Flow batteries today use relatively expensive vanadium compounds to store the energy.

ORBATS will replace the expensive element vanadium and instead use water-soluble inexpensive organic compounds. The project will not only develop the new materials but also the control strategies necessary to optimize the performance of the novel batteries. The new battery type will be demonstrated in a 5-25 kW prototype.

- Water-based flow batteries have every opportunity to become a decisive part of a sustainable energy system with a high demand for energy storage. I am proud that we have succeeded in gathering such a strong project team for this task. The strong industry participation will ensure a short path from the new solutions we as researchers develop, to the application, states Associate Professor Johan Hjelm, DTU Energy, who is leading the project.

- Vestas is working with a number of partners to develop innovative solutions which will bring down the cost of wind energy. We see a great potential in efficient battery technologies as a step on the road towards a fully sustainable energy supply, says Anders Vedel, CTO and Executive Vice President, Vestas.