Grid Storage Brings Second Life To Electric Vehicle Batteries

A project is under way to form a large scale storage system with used electric vehicle batteries.
Published: Fri 06 Feb 2015

Back in August 2013 German luxury car manufacturer BMW and the Swedish utility Vattenfall launched an initiative to assess the re-use of lithium-ion batteries from BMW and Mini electric vehicles (EVs).

With as much as 80% of their storage capacity still available at end of life for EV use, these batteries still have significant storage potential.

Grid-scale storage in Hamburg

Out of this initiative, and following six months of trials, has emerged a project to develop a grid-scale storage system for Vattenfall in Hamburg. The solution, with a proposed 2MWh capacity and output of 2MW, will become part of an already existing Vattenfall virtual power plant and will be operated for a period of ten years. BMW will supply more than 100 batteries from its ActiveE and i3 electric vehicles. After being removed from the EVs, the batteries are re-fabricated and reassembled, before being integrated into the new stationary storage system.

Bosch has also joined the project with responsibility for integrating the batteries and managing the system.

“The project is important because it combines two strategically significant goals,” says Bosch CEO Dr Volkmar Denner. “In electromobility, we see a future mass market accompanied by many new business models and solutions. Stationary energy storage systems that enable people to continue making good use of used batteries are part of this. Such decentralized storage systems allow us to make a major contribution to a secure power supply.”

The storage unit is expected to be operational by the end of 2015.

Second Life Battery Alliance

The three companies have taken the partnership a step further with the launch of the Second Life Batteries Alliance.

Beyond the goal of developing the storage system, the three companies expect to gain numerous new insights into potential areas of application for such batteries, their aging behavior, and their storage capacity.

Bosch’s management algorithm will be used in the solution, with the aims to ensure maximum battery service life and performance as well as other benefits.

Bosch counts several experiences of battery integration in the field. In Braderup, located near the German island of Sylt, the company has built a hybrid Li-ion/vanadium redox storage system to store the energy generated by a community wind farm. In Kelsterbach, a community close to Frankfurt, Bosch has installed a similar Li-ion system at a 180 unit housing complex for solar PV storage.