Electric city bus and infrastructure demonstration environment in Espoo, Finland

Juhani Laurikko, Mikko Pihlatie, Nils-Olof Nylund, Teemu Halmeaho, Samu Kukkonen, Annakaisa Lehtinen, Veikko Karvonen, Reijo Mäkinen, Sinikka Ahtiainen

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    10 Citations (Scopus)


    VTT has together with several partners created a multi-dimensional demonstration environment for electric busses and their supporting infrastructure. The on-going demonstration in the city of Espoo - part of the Helsinki Metropolitan area - is unique in many aspects. One of them is the weather: due to the local climate conditions, the ambient temperature can swing up to 60 °C between high summer and mid-winter. This certainly stresses the vehicles and their batteries to their limits at both ends of their operational range. Fur-thermore, maintaining comfortable riding conditions requires sufficient heating and cooling of the passen-ger compartment. Therefore, an energy efficient HVAC system that does not jeopardize the total energy balance of the bus is needed. Another important feature of this demonstration and field-trial run is that several different commercially available busses are operated simultaneously on the same line. This approach gives an excellent opportu-nity to benchmarking. Furthermore, the service operations in real driving are supported with in-service data acquisition and chassis dynamometer measurements in a controlled laboratory environment at VTT. Lab measurements enable more accurate determination of the energy use profile in different duty-cycles, and make possible resolving of the contribution of the on-board sub-systems. However, a battery-electric bus is not just a vehicle, but an element in a larger system that encompasses also the charging infrastructure. For coupling and charging, several different topologies are possible, and careful consideration should be given to the planning and dimensioning of the complete system. Further-more, a distributed opportunity charging system allows the reduction of battery for lower costs, but simul-taneously raises the investments in infrastructure. Nevertheless, if the charging points can be utilised by a large number of busses, the net result should be positive. Therefore, the positioning of the charging points needs to be based on the lay-out of the lines and taking into account also the schedules of the busses. Fur-thermore, the roles of different stakeholders need also to be investigated. In addition the experimental research at VTT is directly linked with modelling exercises, enabling adjusting the simulation algorithms with real-world data.
    Original languageEnglish
    Title of host publication28th International Electric Vehicle Symposium and Exhibition 2015 (EVS28)
    Subtitle of host publicatione-Motional Technology for Humans
    PublisherKorean Society of Automotive Engineers KSAE
    Number of pages11
    ISBN (Print)978-151-08092-6-0
    Publication statusPublished - 2015
    MoE publication typeA4 Article in a conference publication
    Event28th International Electric Vehicle Symposium and Exhibition, EVS 28 - Goyang, Korea, Republic of
    Duration: 3 May 20156 May 2015
    Conference number: 28


    Conference28th International Electric Vehicle Symposium and Exhibition, EVS 28
    Abbreviated titleEVS 28
    Country/TerritoryKorea, Republic of


    • cold conditions
    • demonstration
    • electric busses
    • lab measurements
    • systemic approach


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