On a conference call today, hosted by the Electric Drive Transportation Association, Mark Duvall, Director of Electric Transportation at the Electronic Power Research Institute, hammered down a bit on the topic of how much we really need to spend to build an effective charging infrastructure.
"The charging infrastructure to support electric vehicles is not the most complicated problem there is, but it's often a poorly understood problem," Said Duvall. "It's important to note that two-thirds of the time a car is parked at its home parking space, and about another 15% of the time it is parked at work, and every other location for that vehicle is a fraction of a percentage point." It is for just these reasons, remarked Duvall, that we really need to place the "overwhelming focus" on getting at-home and employer-installed charging going, but that our focus on the public infrastructure is misplaced.
In terms of home installations there are complications with getting condominium and homeowners associations to put in banks of charging stations for the residents that are purchasing electric vehicles and apartment dwellers could be out of luck, but, as several respondents on the call pointed out, the first wave of EVs is not really targeted at those kinds of customers. Over time, it is hoped, we will come up with solutions.
As for business installations, Duvall said that EPRI "really thinks it's a positive if employers provide charging facilities for their employees to use." If an employer wants to attract and keep their employees who drive plug-ins, it's a pretty simple equation, no? "A lot of times people point out that [business charging] could potentially cause charging on peak, but in reality, if you look at how the vehicles are driven a typical workplace charging scenario would have the cars charging in the morning with almost all the cars fully charged before the afternoon peak starts," added Duvall.
One of the most interesting aspects of Duvall's comments came in relation to the whole public charging infrastructure debate. As I've said before, I think most public charging stations will sit idle and unused most of the time, and Duvall seems to share that sentiment.
"It's very important to understand that this infrastructure is very expensive and has a somewhat uncertain business case," he said. "There's almost a controversy over how much charging public infrastructure is actually needed. Once we start using vehicles and collecting information on them, I think we'll understand that we can cost effectively support a lot of vehicles on a very reasonable amount of infrastructure. Vehicles are parked at home or in front of the workplace about 80% of the time, and they're driving 5% of the time, so they don't need to spend a lot of time at these public infrastructure installations."
Certainly public charging is going to present a conundrum. We don't really even know if anybody's going to use it, but governments and utilities are concerned that without it people won't buy the cars.