Research project examines PV-supported charging infrastructure for electric buses
The acronym EMOSYN stands for “Electromobility, Smart Grid and Self-Generation.” Under this heading, a research team from Kiel University of Applied Sciences has been supporting the Pinneberg District Transport Company (KViP) for almost four years in the electrification of part of its bus fleet and assisted the company in the design, commissioning, optimization, and scaling of a pilot plant at its depot in Uetersen, Schleswig-Holstein.
A total of 100 kW of photovoltaic power was installed on the depot's administration building and maintenance hall. A battery storage system with a capacity of 328 kilowatt hours was housed in a container on the site. At the start of the project, a 50 kW charging station connected to the battery storage system was in operation, explained Klaus Lebert, a professor at the department of Computer Science and Electrical Engineering at Kiel University's Institute of Mechatronics. A second charging station near the storage system went into operation in the second half of 2024.
The research project, supported by the Federal Ministry of Transport and Digital Infrastructure with around €312,000 ($349,257) – of which around €154,000 went to the university – has now been completed, and the evaluation was submitted at the beginning of this year. For the Kiel University of Applied Sciences, however, the project is seen as the potential beginning of a more far-reaching plan: “The development of the energy supply infrastructure for the electrification of depots and bus fleets is quite complicated and associated with financial and logistical challenges,” said Lebert. The pilot project has now produced “a model that can serve as a kind of blueprint for other small and medium-sized public transport providers to implement a similar approach.”
The project investigated how energy generated by photovoltaics can reduce the use of grid electricity and thus contribute to cost reduction. Modeling, simulation runs, and continuous comparison with real-time data have resulted in “a highly accurate overall model for the depot.” This enabled charging strategies to be evaluated and concrete recommendations to be developed.
KViP intends to continue to utilize the findings. “We now know the relevant technical, operational, and economic parameters for integrating our own renewable energy generation into our electrification strategy,” said managing director Thomas Becker. In addition to the self-generated stations, the company now operates five additional 120 kW stations, which are currently powered by grid electricity. Twenty-seven more are to follow shortly, which will be necessary: 27 electric buses have been ordered and are scheduled to be integrated into the KViP fleet starting in late summer.