DB Energie and Adaptive Balancing Power (ABP) have agreed to trial a flywheel energy storage system on the Berlin suburban rail (S-Bahn) network’s DC network as part of the Peak_S pilot project. The system is designed to capture braking energy, which until now has largely been lost as heat, via the conductor rail, store it mechanically in the rotating flywheel and, when required, feed it back into the grid as electrical energy, for example to start electric multiple units (EMU). This is intended, in particular, to relieve the upstream AC traction power grid. At the same time, the project is investigating the impact on the existing power supply infrastructure. It is expected that the storage facility will relieve the load on the rectifier substations and stabilise the grid voltage. The resulting capacity reserves could support demand-driven grid expansion and reduce investment in upgrades and new construction. Once the specifications have been approved and the contract signed, the storage facility is scheduled to go into operation in 2027. During the subsequent 12-month test phase, DB Energie and ABP will assess performance, grid impact and cost-effectiveness under real operating conditions. The results are intended to lay the groundwork for the potential wider deployment of such storage facilities across Berlin’s S-Bahn network.
