Electric buses (E-buses) are increasingly replacing internal combustion powered bus fleets. They can further function as distributed energy storage units. We investigate the feasibility of the novel “Bus-to-Grid” (B2G) or “E-Buses as Power Storage” (EBaPS) concept, which allows battery E-buses to provide transportation as well as power-grid services. By aggregating the electrified bus fleets into Virtual Power Plants and discharging the energy to the grid, a bus operator can provide grid services and open up a secondary revenue source in addition to fareboxes. We discuss two contracts the bus operator can arrange with the grid. The first one is “Sale by Market Price (SbMP)”, presuming that the buses can discharge and sell the energy at real-time market prices. The second one is “Frequency Control Reserve (FCR)”, in which the buses discharge on immediate requests of the grid. We formulate the two contracts and their associated fleet allocation problems as two non-linear optimization problems maximizing the operator’s profit. Optimal bus charging, discharging, and dispatching plans are solved on an aggregate level for strategic planning, allowing scalability to large fleet sizes. The profitability of the contracts is illustrated based on the schedule and demand of a real bus line and observed time-of-day dependent price variations of the energy market.

电动公交车 (E-bus) 越来越多地取代内燃动力公交车队。它们可以进一步充当分布式储能单元。我们研究了新颖的“总线到电网”(B2G) 或“电动巴士作为电力存储”(EBaPS) 概念的可行性，该概念允许电池电动巴士提供运输和电网服务。通过将电气化公交车队聚集到虚拟发电厂并将能量输送到电网，公交运营商可以提供电网服务并开辟除票务之外的第二个收入来源。我们讨论公交运营商可以与电网安排的两份合同。第一个是“按市场价格销售（SbMP）”，假设公交车可以按实时市场价格排放和销售能源。第二个是“频率控制储备（FCR）”，公交车根据电网的即时要求放电。我们将这两个合同及其相关的车队分配问题表述为两个非线性优化问题，以最大化运营商的利润。最佳公交车充电、放电和调度计划在战略规划的总体层面上得到解决，允许扩展到大型车队规模。合同的盈利能力是根据实际公交线路的时间表和需求以及观察到的能源市场随时间变化的价格变化来说明的。允许可扩展到大型车队规模。合同的盈利能力是根据实际公交线路的时间表和需求以及观察到的能源市场随时间变化的价格变化来说明的。允许可扩展到大型车队规模。合同的盈利能力是根据实际公交线路的时间表和需求以及观察到的能源市场随时间变化的价格变化来说明的。