(Press-News.org)
Even if enough renewable energy is available, simply switching from gas-powered cars to electric vehicles (EVs) won’t be enough to fight climate change — unless the U.S. also upgrades its transmission grid, a new Northwestern University study finds.
If every gas-powered vehicle in the U.S. were replaced by an EV, transmission constraints would prevent the cleanest available electricity from reaching many charging locations. This “grid congestion” would force greater reliance on nearby fossil fuel power plants, undercutting the emissions benefits of electrification.
After identifying the issue, the study also recommends a modest set of targeted transmission grid upgrades to alleviate congestion and unlock the full emissions-reduction potential of EV adoption.
The study was published today (Aug. 6) in the journal Nature Communications.
“Even if the U.S. fully adopts EVs and generates enough renewable electricity to charge them, it still won’t be enough,” said Northwestern’s Adilson Motter, who led the study. “We found the limiting factor for cars to be powered by clean energy has less to do with the availability of renewable energy and more to do with the ability to transmit that energy from generation sites to where it’s needed. The power lines are congested, and that leads to congestion-induced CO2 emissions.”
An expert on complex systems, Motter is the Charles E. and Emma H. Morrison Professor of Physics at Northwestern’s Weinberg College of Arts and Sciences and the director of the Center for Network Dynamics. Motter conducted the research with Chao Duan, a former Research Assistant Professor at Northwestern.
The grid gets in the way
Like a highway system, the power grid is a vast infrastructure that transmits electricity across the U.S. After being generated at plants, electricity travels long distances through high-voltage transmission lines that span entire states and regions. It then reaches substations, where its voltage is reduced. Power then flows through distribution lines to homes, businesses and EV charging stations.
To analyze electricity’s journey through power lines, the researchers combined data on vehicle usage and power grid infrastructure. Using advanced computer models, the team simulated the flow of electricity across the U.S. under varying levels of vehicle electrification and renewable energy generation
In every scenario with high EV adoption, grid congestion emerged as a critical bottleneck.
As EV adoption increases, so does electricity demand, especially in urban areas. But renewable energy sources like wind and solar are typically located far from cities, such as on rural wind farms or solar arrays in the desert. While clean energy is available, transmission capacity is often too limited to deliver it where it is needed, including EV charging stations. As a result, the grid draws electricity from closer — but more polluting — power plants that generate electricity by burning coal, oil and gas.
In the study’s most ambitious simulation, scientists converted the entire U.S. vehicle fleet to electric. If the grid had adequate transmission capacity, this shift could eliminate nearly all vehicle-related CO2 emissions once renewable energy matches nonrenewable energy generation. But, with current grid constraints, one-third of those potential emissions savings would be lost.
“The charging schedule of EVs can be optimized to align with intermittent renewable generation,” Motter said. “But even with smart charging, efficient use of clean energy still depends on having enough transmission capacity to deliver it where it’s needed.”
Smart, targeted upgrades
To address this bottleneck, the researchers calculated how much additional transmission capacity would be needed. They found that increasing the existing grid’s transmission capacity by as little as 3 to 13% would significantly reduce congestion. This could involve building new high-voltage lines or expanding existing ones — enabling more clean power from remote wind and solar farms to reach the cities and suburbs where EV charging demand is highest.
Motter stresses that the entire grid does not need to be rebuilt. Instead, he recommends targeted upgrades in areas where congestions are most likely to occur. The U.S. grid is divided into three largely independent regions — Eastern, Western and Texas — with limited ability to transfer power among them. Improved connections and coordination among regions would help clean energy reach the areas that need it most.
“Power grids began as local networks, where consumption was close to generation,” Motter said. “Over time, they evolved into nationwide — even continent-wide — systems. It was a gradual growth process built on existing infrastructure. No one wants to redesign it from scratch, but we do need targeted upgrades that reflect the large-scale reach of today’s grid.”
The study, “Grid congestion stymies climate benefit from U.S. vehicle electrification,” was supported by Leslie and Mac McQuown through the Center for Engineering Sustainability and Resilience, a Resnick Award from the Paula M. Trienens Institute for Sustainability and Energy and the National Natural Science Foundation of China.
END
While overdose deaths in the U.S. sharply declined in 2024, they remain high. Almost 90,000 Americans died from drug overdoses between October 2023 and September 2024. Overdose death rates are particularly high in American Indian and Alaska Native (AI/AN) people.
The earlier someone starts substance use, the more likely they are to have substance use problems later in life. So, it is important to work with young people to prevent substance use early in life. Researchers at Emory’s Rollins School of Public Health recently partnered ...
(Santa Barbara, Calif.) — Researchers at UC Santa Barbara have found that better access to technology can go a long way toward achieving equity in healthcare for African Americans in the United States. According to Sharon Tettegah and Ebenezer Larnyo, both researchers at UCSB’s Center for Black Studies Research (CBSR), leveraging health technology is a promising strategy for addressing longstanding healthcare disparities “by enhancing access to care, improving its quality and reducing inequities.”
“Our study shows that improving access to technology like broadband internet and smartphones, and healthcare technology use like ...
The study examined over a thousand women aged 18 to 49. Of these, 358 had suffered an ischemic stroke. Researchers compared the pregnancy histories of these women with those of 714 women who had not experienced a stroke. The results showed that more than half of the women who had an ischemic stroke had experienced at least one complication during pregnancy. In the group without ischemic stroke, this was one-third.
Women who had experienced a stillbirth were found to be nearly five times more likely to ...
EMBARGOED FOR RELEASE UNTIL 4:00 P.M. ET, WEDNESDAY, AUGUST 6, 2025
MINNEAPOLIS – Experiencing complications during pregnancy is linked with a higher risk of stroke before age 50, according to a study published August 6, 2025, in Neurology®, the medical journal of the American Academy of Neurology. Researchers found female participants who had certain pregnancy complications were more likely to have an early stroke. These included preeclampsia, preterm birth, gestational diabetes, miscarriage and stillbirth. The study does not prove that pregnancy complications cause stroke. It only shows an association.
“While the ...
CHICAGO – Older patients whose primary language is not English may be at greater risk for delirium after surgery in American hospitals. People who struggle with food insecurity or loneliness may be more likely to experience chronic pain after surgery. Fentanyl overdose deaths in older adults are rising at similar rates to younger people. When anesthesiologists lead preoperative care for hip fractures, patients get to the operating room faster and recover better. These findings and other timely research ...
Captive cockatoos have at least 30 different dance moves in their repertoire, including headbanging and body rolls, according to a study by Natasha Lubke at Charles Sturt University in Australia, and colleagues, publishing August 6, 2025 in the open-access journal PLOS One. The moves, of which 17 are newly identified, may be performed with or without music.
Several species of parrot have been anecdotally observed dancing to music in captivity. Dancing results from complex brain processes including imitation, ...
A new analysis of data on scientists with exceptional early-career success—according to a metric known as citation impact—has identified common characteristics among them, some of which could also be indicators of problematic or fraudulent behaviors. John Ioannidis of Stanford University, U.S., presents these findings in the open-access journal PLOS One on August 6, 2025.
Citation impact reflects a scientist’s overall influence in their field, which depends, in part, on the number of ...
Adolescent girls who have weight concerns despite not being obese are more likely to also experience depression and suicidality, per Korean survey of more than 50,000 middle and high school students
Article URL: http://plos.io/4m9mewW
Article title: Sex differences in the association of BMI and weight perception with depression and suicidality among Korean adolescents
Author countries: Republic of Korea
Funding: The author(s) received no specific funding for this work. END ...
Two-thirds of dogs tested in a recent survey consume higher-than-recommended levels of heavy metals in their drinking water, according to a study published August 6, 2025 in the open-access journal PLOS Water by Audrey Ruple from Virginia Tech, U.S., and colleagues. The survey, which focused on well water households in 10 states, uncovered 13 instances where arsenic, lead and copper tested above EPA-recommended levels.
Roughly 15 million U.S. households use private well water and are not protected by the EPA’s Safe Drinking Water Act, which regulates safety testing in drinking water. These households — and the canine companions inside — ...
Analysis of ocean sediments has surfaced geochemical clues in line with the possibility that an encounter with a disintegrating comet 12,800 years ago in the Northern Hemisphere triggered rapid cooling of Earth’s air and ocean. Christopher Moore of the University of South Carolina, U.S., and colleagues present these findings in the open-access journal PLOS One on August 6, 2025.
During the abrupt cool-off—the Younger Dryas event—temperatures dropped about 10 degrees Celsius in a year or less, with cooler temperatures lasting about 1,200 years. Many researchers believe that no comet was ...
