This paper was our first on sustainability-related topics.  As mentioned in the Acknowledgment, it was  inspired by  Professor David Boyce’s 2012 trip from Chicago, IL to Madison, WI.  At the time, he just bought a Nissan Leaf (one of the first successful battery electric vehicle models, with a whooping range  of 70 miles！), and was eager to prove it can be used for long-distance travel.     Due to the limited availability of charging stations back then, however, he was forced to spend one night at a hotel that was less than 20 miles from Madison, turning a four-hour trip to an overnight one.

David’s adventure got me into the EV infrastructure planning, which eventually led to this paper, and a PhD thesis completed by Mehrnaz Ghamami.  The core idea  of this paper is the consideration of the tradeoff between battery cost and charging stations in EV infrastructure planning. That is, from a system point of view, how should social  resources be allocated between manufacturing larger batteries and building more charging facilities?  Check the abstract below for our main findings, and you can also download  Preprint  here.

The paper was published in Transportation Research Part B in 2013.

Abstract: The transition to electric vehicles (EV) faces two major barriers. On one hand, EV batteries are still expensive and limited by range, owing to the lack of technology breakthrough. On the other hand, the underdeveloped supporting infrastructure, particularly the lack of fast refueling facilities, makes EVs unsuitable for medium and long distance travel. The primary purpose of this study is to better understand these hurdles and to develop strategies to overcome them. To this end, a conceptual optimization model is proposed to analyze travel by EVs along a long corridor. The objective of the model is to select the battery size and charging
capacity (in terms of both the charging power at each station and the number of stations needed along the corridor) to meet a given level of service in such a way that the total social cost is minimized. Two extensions of the base model are also considered. The first relaxes the assumption that the charging power at the stations is a continuous variable. The second variant considers battery swapping as an alternative to charging. Our analysis suggests that (1) the current paradigm of charging facility development that focuses on level 2 charging delivers extremely poor level of service; (2) the level 3 charging method is necessary not only to achieve a reasonable level of service, but also to minimize the social cost, (3) investing
on battery technology to reduce battery cost is likely to have larger impacts on reducing the charging cost; and (4) battery swapping promises high level of service, but it may not be socially optimal for a modest level of service, especially when the costs of constructing swapping and charging stations are close.