Energy storage systems play an important role in the electrification and decarbonization of road and rail transport. Efficient energy stores are a fundamental requirement for the operation of e-buses and e-trucks, and, for example, allow braking energy generated by recuperation to be stored. By integrating energy storage systems into vehicles, diesel trainsets can be converted into diesel hybrid vehicles, cutting CO2 emissions by up to 30%. This technology thus offers transport operators many options for retrofitting their vehicle fleets in order to achieve more sustainable mobility.