In a new report released on July 29, 2020, the Pacific Northwest National Laboratory (PNNL) in Washington state found that the U.S. energy grid will be able to handle growth in electric vehicle (EV) charging demand until 2028, but after that, the grid will need costly updates or smarter charging to maintain reliability.[1] The report based its analysis on information from the Western Electricity Coordinating Council (WECC), the grid authority west of the Rocky Mountains, because it has commonly agreed-upon data set for a future grid scenario called the WECC 2028. The study is the first to consider medium- and heavy-duty trucks in addition to light-duty trucks. The report’s authors concluded that the current grid could support up to 24 million EVs (including 200,000 medium-duty trucks and 150,000 heavy-duty trucks), which the report predicted the U.S. would reach in 2028. Currently, there are about 1.5 million EVs.

The study looked at two scenarios for how to handle the effect of EVs surpassing this milestone. The first is based on current actions and assumes that most charging sessions will continue to begin at the end of the day, with drivers plugging in and drawing electrons at the same time in the evening. Under this scenario, utilities would need to build new transmission lines and power plants fueled by natural gas to meet demand and keep reliability. The other scenario imagines a system where the battery-filling schedule is coordinated with the needs of the electric grid. This scenario relies on technologies that are in development but have not been tested at scale. Under this scenario, the number of vehicles that the grid can handle more than doubles to 65 million vehicles.

[1] https://www.pnnl.gov/sites/default/files/media/file/EV-AT-SCALE_1_IMPACTS_final.pdf