NREL Research Supports Equitable Deployment of Electric Vehicle Charging Infrastructure

Oct. 27, 2021

Photo of electric vehicle charging in the foreground, with a person at the door of a home in the background.

Electric vehicles (EVs) have surged in popularity during recent years as car companies continue to bring new models to market. EVs tend to be popular with consumers for a variety of reasons including the low cost of driving on electricity and the instant torque provided by electric drive technology. Further, EVs emit no tailpipe emissions, and the upstream emissions associated with charging decrease every year as more renewables are brought onto the grid.

However, these benefits hinge on having somewhere to charge that is convenient, affordable, and reliable. For many of today's EV owners, that place is at home, often parked overnight in a personal garage. While this is not a viable solution for everyone, there is much uncertainty regarding how many vehicles could be charged at home and how much public charging infrastructure will be necessary for those that cannot.

A new National Renewable Energy Laboratory (NREL) report, There's No Place Like Home: Residential Parking, Electrical Access, and Implications for the Future of Electric Vehicle Charging Infrastructure, sheds light on the potential for residential charging access. Authored by NREL's Yanbo Ge, Christina Simeone, Andrew Duvall, and Eric Wood with funding from the Department of Energy's Vehicle Technologies Office, the report provides insight into potential roadblocks for residential charging access.

"Gaining a better understanding of the current state, as well as the future potential, for residential EV charging helps inform policymakers," lead author Yanbo Ge said. "To support national decarbonization goals, reaching all groups in the population is essential. We now have a better idea as to where residential charging barriers exist, which can help guide infrastructure investments."

If consumer demand for EVs meets some industry projections, charging infrastructure must be deployed at a large scale soon. The White House already has called for the installation of a half-million new chargers by 2030 and wants half of new passenger cars sold by then to be zero-emission vehicles—a category that includes EVs.

NREL analysis indicates that, as EV adoption progresses, residential charging access among EV owners is likely to decrease and become more uncertain. This is due to the increased prevalence of challenging environments for installation of residential charging as the market grows, including for both the new and used vehicle markets. Individuals living in multi-family housing, renters, and those using on-street parking are expected to experience the greatest challenges in accessing charging while at home.

This research highlights several opportunities to improve residential charging access as markets evolve, including consumer education, investment in residential infrastructure at single- and multi-family homes, behavior-change opportunities to take advantage of residential parking locations with convenient electrical access, and sharing of residential infrastructure within multi-vehicle households.

Despite these strategies, this study estimates that in the long term at least a quarter of the U.S. population will not have reliable access to home charging.

"In situations where residential access is unlikely, investments in charging infrastructure at workplaces, curbside in dense urban settings, and public fast charging are strategies to improve equity of access," Ge said. "There is an important element of educating the population on EV charging. Normalizing the practicality of EV ownership, in part through easier access to charging, will enable more people to gain from the many benefits of this technology."

Core to this research was a nationwide survey of 3,772 people that determined a third of today's personal vehicles are currently parked at home in a location with electrical access and well positioned for installation of charging infrastructure. Under a future scenario in which every vehicle is electric, the most optimistic scenario predicts 25% would lack access to home charging, 45% of which would be from single-family detached homes and 40% from apartments. The sheer number of vehicles owned by residents of single-family homes is so large that even a small share of single-family homes without access to charging becomes a substantial barrier to vehicle electrification at the national level.

This research leverages some of NREL's integrated data and analysis tools, including the EV Infrastructure Projection Tool, the Automotive Deployment Options Projection Tool, and the Transportation Energy and Mobility Pathway Options Tool. Insights are directly informing charging infrastructure planning studies at the city, state, and national levels.

Read more about NREL's EV grid integration research and infrastructure analyses for Kansas City, Missouri, and the state of California.