Sustainable charging on the TU Berlin campus
Could old lithium-ion batteries be given a second life storing energy for e-bikes on the TU campus? A team of researchers at TU Berlin are working on just that in the sustainability project “Select.” Their solar-powered e-bike station serves more than research, though; it is also a climate-neutral transport solution for getting students from A to B.
Most people can hardly imagine life without batteries. Lithium-ion batteries can be found almost everywhere now: in smartphones, laptop computers, headphones, e-bikes and other electric vehicles. They are compact, inexpensive and energy-dense, but their usable capacity falls during their lifetime and drops lower and lower over time. Many components in the cells making up the batteries are ultimately disposed of as waste because only a few of the materials can be profitably recycled. Lithium, in particular, is complex and expensive to recycle. But many parts of these batteries are often still usable. Cheap new batteries can be built from them and used, for example, as energy accumulators for e-bikes. TU Berlin is using old batteries as second-life storage in its project “Second Life E-Bike Charging Station” (SELECT). The project is being carried out under the aegis of the Chair of Electrical Energy Storage Technology held by Professor Julia Kowal.

Image: F.Salinas-Barros
SELECT is an e-bike charging facility on the TU Berlin campus with covered parking and charging facilities for up to eight e-bikes at a time—and it is entirely solar powered. In line with the priority of conserving resources, the bike shelter, which has a roof but is open to the side, will operate completely autonomously with no connection to the mains electricity grid. The e-bike station is supported by the Council for Sustainable Development at TU Berlin to cut down on trips made using private automobile transport.
It will also be used in teaching and further research. More than 150 batteries have already been dismantled within the scope of the doctoral project of Chilean scholar Felipe Salinas, and a battery prototype for the e-bike station has been produced. In addition, alternative charging processes can be implemented, new or additional battery storage can be deployed, and research into the aging of batteries and into the connections between e-bike use, solar yield and storage capacity can be carried out under entirely authentic conditions.