Researchers at North Carolina State University have created a mathematical model for optimal placement of EV charging stations, as well as how powerful stations can be without straining local power grids.

"Ultimately, we feel the model can be used to inform the development of EV charging infrastructure at multiple levels," Leila Hajibabai, corresponding author of a paper detailing the model and an NC State assistant professor, said in a statement.

Significant research has already been done on how to deploy EV charging infrastructure, but most previous efforts only focused on what was best for the grid, or what was best from a user demand standpoint, according to an NC State press release.

Porsche electric-vehicle charging station

Porsche electric-vehicle charging station

"Very little work has been done that addresses both," Hajibabai said, adding that the mathematical model also considers user behavior. The best locations based on the grid, transportation needs, and user behavior are often different, so the model aims to find the best compromise, according to Hajibabai.

The grid component of the model looks at local infrastructure, including factors like power flow, voltage and current. A transportation component considers the number of vehicles expected to use a station, the routes they're traveling, and average range. The user decision-making component looks at which sites will minimize travel time.

While this model tries to find the most efficient use of resources, there are other factors to consider when choosing a charging site. The model doesn't appear to consider low-income users, or disadvantaged communities that might have the most to gain.

Electrify America upscale charging concepts

Electrify America upscale charging concepts

A widely-applicable template for charging infrastructure location and design still hasn't emerged.

Neither gas stations, nor their locations, are a good model for EV charging. We've long suggested that for slower charging, those who site charging should look to the parking.

But for the federal EV charging network that's taking form, there might be some use in this as a tool for locating fast-chargers. The researchers are also in talks with state and local governments, as well as utilities, to use the model in developing North Carolina's charging infrastructure.