Audi And RWE’s New Energy Storage Facility, Giving EV Batteries A Second Lease On Life

Driving the energy revolution forward, Audi and RWE have brought an energy storage facility on stream in Herdecke, Germany, that employs used lithium-ion batteries from Audi electric cars.

With the help of 60 battery systems, the new type of storage facility at RWE’s pumped-storage power plant on Lake Hengstey will be able to temporarily store 4.5 megawatt hours of electricity.

Audi AG’s board member for technical development, Oliver Hoffmann, expressed, “Carbon-neutral mobility is Audi’s ultimate goal. This partnership with RWE is intended to demonstrate the possibilities that exist for the resource-friendly use of second-life high-voltage batteries and their intelligent integration into the power grid of the future. In addition, we are already thinking about the time after this utilisation phase and are stepping up our efforts to ensure that batteries are recycled effectively.”

As aforementioned, the decommissioned batteries provided for the project come from Audi e-Tron development vehicles.

Mainly because after their first life in the car, they still have a residual capacity of more than 80 percent, making these ‘second-life batteries’ perfect for use in stationary power storage systems.

Plus, depending on how they are utilised, these batteries still have up to ten years of remaining service life, and they are also significantly cheaper than new cells. 

On the site, RWE has already built a 160-square-meter hall in lightweight design for the 60 battery modules, which weigh around 700 kg. 

The installation of the battery systems inside the hall was completed in October, and individual components were brought on stream beginning in November.

RWE Generation SE’s chief executive officer, Roger Miesen, commented, “Powerful battery storage plays an essential role in the energy revolution. Flexible storage technologies are needed to compensate for short-term fluctuations in renewable energy and stabilise the grid. Battery storage systems are ideally suited for this purpose. Along with Audi, in Herdecke, we’re testing how end-of-life high-voltage batteries from electric cars behave as stationary energy storage devices when connected together. The continued use of such ‘second-life’ storage is a sustainable alternative to brand-new batteries. The experience gained from this project will help us identify the applications in which we can most cost-effectively operate such battery systems.”

That said, the findings from the reference storage facility in Herdecke will help RWE build and operate larger storage facilities based on EV batteries in the future.