Avdevicius, Edvard

The importance of electrifying buses in public transportation is increasing massively during the last few years. This owes to the health detrimental emissions of diesel buses and their effect on the climate changes. Correspondingly, the two transportation companies in Hamburg, the Hamburger Hochbahn AG and Verkehrsbetriebe Hamburg-Holstein GmbH (VHH), decided to electrify their bus depots. This ambitious goal is combined with many challenges concerning the design and operation of the charging infrastructure at the minimum costs. Among others also load management, grid impact, power quality. The aim of implementing the presented model is to search for possible usage of flexibility of electric bus depots in the energy market. This is realized by considering the bus depot as an aggregator of positive or negative flexibility. The offering of this flexibility is based on the predefined atypical grid usage in Germany. This enables electricity customers with an annual energy consumption of more than 100,000 kWh to save in grid fees for their load regulation in coordination with grid operators. Nevertheless, the operation of the bus depot has the highest priority in this study to guarantee the ability of buses to travel their routes. This paper analyses three different scenarios for atypical grid usage: the role of load management, the role of a second-life stationary battery and the combination of both cases. As a result, the required supplying periods and capacities of the stationary battery are calculated. Finally, a combined scenario between the supply from the stationary battery and the supply from the grid is presented.

The transition towards sustainable energy systems has led to an increasing integration of renewable energy sources and the electrification of transportation. As the adoption of electric vehicles (EVs) continues to grow, leveraging their capabilities to enhance the resilience of electrical grids becomes an intriguing possibility. EVs are capable of providing emergency power supply in a variety of situations. When traditional power sources are unavailable or unreliable, EVs can be used as backup power sources to provide electricity to homes, businesses, hospitals, and other critical infrastructure. One of the primary benefits of using EVs for emergency power supply is their ability to store large amounts of energy in their batteries. In addition to their energy storage capabilities, EVs can also be used as mobile power sources. Overall, the use of EVs for emergency power supply has the potential to improve preparation, response, and to provide a more reliable source of electricity during power outages and other emergencies. This study presents an optimization methodology of calculating possible support of electric bus depots in emergencies using Mixed-Integer Linear Programming (MILP). It targets simulating possible utilization of mobile energy storage in the improvement of power system resilience through Vehicle-to-Storage (V2S) implementation.

Owing to the immense climate changes recently, the city of Hamburg has decided to allow the purchase of only emission-free buses for public transportation. Meanwhile, Hamburg focuses on the implementation of electric buses. For this purpose, the two public transportation companies in Hamburg which are the Hamburger Hochbahn AG (HOCHBAHN), and the Verkehrsbetriebe Hamburg-Holstein GmbH (VHH) decided to build new charging infrastructure for electric bus depots. In addition, they started by electrifying their existing stations. This study proposes an optimal method for electrifying bus depots by modularizing the subsystems in electrical power systems. An approach that allows the study of different configurations of power system components. Analyzing these configurations results in the conclusion of the most technically feasible configuration, achieving the lowest cost. Furthermore, the model objectives include reducing the required area, which is a challenging criterion for bus depots in many cities. Mixed-Integer Quadratic Programming (MIQP) is used to generate this combination based on predefined constraints that must satisfy all implemented constraints of the system.