EV Charging – It’s All in the Location

Ally Winning, European Editor, PSD


North Carolina State University has developed a computational model that can be used to calculate the best places for locating EV charging facilities


EV Charging is all about location


This week brought more worrying news about the climate. A new report from the World Meteorological Organization estimates that we now have a 48% chance of global average temperatures temporarily rising above 1.5 degrees Celsius beyond pre-industrial levels within five years. 1.5 degrees Celsius is nominally the preferred warming limit set by the 2015 Paris Agreement, meaning that it is the temperature that we hope will be enough to avoid the worst impacts of climate change.


The easiest and quickest way for the world’s governments to try fulfil their commitments to meet emissions targets and to hopefully ensure that any rise above 1.5 degrees Celsius is only temporary is to electrify transportation in their areas. However, a big stumbling block to that electrification is range anxiety for customers, who would like to know that there are plenty of available chargers between them and their destination. Over the last year or so, many countries, vehicle manufacturers and organizations have pledged to build out the infrastructure and hundreds of thousands of charging points are either being installed around the world, or are planned. But, are the chargers going to be in the correct location to provide the best service? There are several involved parties to charger location. Where is best for the consumer might not necessarily be the optimal location for the power company, or even the local municipal government and communities who could be left to maintain the infrastructure throughout its operational lifetime. Identifying the best sites for charging facilities is a complicated process, which has to account for travel flow and user demand, as well as the needs of the regional power infrastructure.


Researchers from North Carolina State University looked at that situation and developed a computational model that can be used to calculate the best places for locating EV charging facilities, and how powerful those charging stations can be without placing an undue burden on the local power grid.


“Ultimately, we feel the model can be used to inform the development of EV charging infrastructure at multiple levels, from projects aimed at supporting local commuters to charging facilities that serve interstate highway travel,” says Leila Hajibabai, corresponding author of a paper on the work and an assistant professor in NC State’s Fitts Department of Industrial and Systems Engineering.


Most previous efforts on charging infrastructure location focused on what would work best for the power system, or what would work best from a transportation standpoint. Very little work had been done that addresses both. And those cases that looked at both power and transportation systems did not take into account the decisions that users make.


The power system component of the model accounts for the limitations of the power distribution network – its power flow, voltage, current and so on. The transportation component of the overarching model accounts for the number of travellers, the routes that they take when travelling, and how far their vehicles can go before they need to be recharged. To account for user decision-making, the model tries to identify locations that will minimize travel time.


The paper, “Joint Power Distribution and Charging Network Design for Electrified Mobility with User Equilibrium Decisions,” is published open access in the journal Computer-Aided Civil and Infrastructure Engineering. The paper was co-authored by Asya Atik, a Ph.D. student at NC State, and Amir Mirheli, a former Ph.D. student at NC State.