How can electric vehicles (EVs) contribute to lower power grid emissions? This is what a recent study published in Environmental Science & Technology hopes to address as a team of researchers investigated how strategically using EV charging stations could provide increased environmental benefits. This study has the potential to help scientists, engineers, and the public better understand the myriad of environmental benefits that EVs provide aside from being zero-emission vehicles.
For the study, the researchers created a model to ascertain the infrastructure and operational impacts of charging EVs at the end of the day, as opposed to charging them periodically. Their control group was PJM, which is the largest regional power grid operator in the United States. In the end, the researchers found that charging EVs everyday could be more harmful than good, while charging them periodically would allow charging stations to discharge back to the grid while providing increased load benefits. Essentially, less is more regarding the environmental, operational, and infrastructure impacts of charging EVs.
"You'd think if you're buying more electricity, you'd be creating more emissions, but it turns out you can actually reverse it, if you charge your vehicle at the right time. We call it 'negative vehicle emissions,'" said Dr. Jeremy Michalek, professor of mechanical engineering and of engineering and public policy at Carnegie Mellon University and a co-author on the study.
This study comes as the number of EVs continues to increase globally, with EVs comprising approximately 20 percent (17 million) of all vehicles. Additionally, EV sales reached a record 438,000 in the third quarter of 2025 with the number of charging ports increasing to 217,000. Therefore, studies like this could help smooth the transition to EVs while providing increased environmental and health benefits.
What environmental benefits will EV charging stations have in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Environmental Science & Technology, EurekAlert!, IEA