RWE was early to recognise the potential and the need for energy storage systems, which are becoming increasingly important as the expansion of renewables continues. As a driver of the energy transition, RWE also researches and develops the use of battery storage systems from used electric vehicle batteries (“second life”) or redox flow systems, and other storage technologies.
Second-life batteries from electric vehicles
In Herdecke, North Rhine-Westphalia, RWE has put an energy storage system into operation that makes use of used lithium-ion batteries from Audi EVs. The “second-life batteries” that are used come from Audi e-tron development vehicles, and after their “first life” in the car, they still have a residual capacity of more than 80 percent. Depending on how they are used, that means the batteries could still have a remaining service life of up to ten years. And they are cheaper than new cells. That means they are ideally suited for use in stationary electricity storage systems.
Redox flow batteries – panta.rhei
Redox flow battery storage systems offer the crucial benefit that their power and capacity can be independently scaled. This technology also ages much more slowly than traditional batteries. Currently, this technology is still relatively expensive in terms of the stored capacity provided. That can change quickly, however, as has already been observed with a sister technology, lithium-ion batteries. That is why RWE is performing research into this technology at a 130 kW pilot facility as part of the panta.rhei project at the RWE Campus in Essen.