Electrification of vehicles is necessary to reduce greenhouse gas emissions, but in Quebec the increasing weight of the battery-powered vehicles could cause electricity demand to rise well beyond projections.

That’s the conclusion of an analysis by Université de Montréal researchers Frédérik Lavictoire and Simon Brassard, supervised by Normand Mousseau, a professor in the Department of Physics.

Their results are published in the journal Sustainable Futures.

Cars are getting heavier

Between 2011 and 2021, the average weight of vehicles sold in Quebec increased by 11 kg per year for over 10 years, from 1,566 kg to nearly 1,700 kg.

New vehicles weigh an average of 135 kg more than the existing fleet average, while vehicles that are being retired are 104 kg lighter. A vehicle purchased today weighs an average of 110 kg more than the one it replaces.

With 60,000 vehicles being added to Quebec’s fleet each year, the cost of maintaining the road network—and the electrical grid—is likely to be steep, the UdeM researchers say.

Small SUVs, which accounted for 12.6% of the fleet in 2011, have surged in popularity to reach 28.3% in 2021. They have been the leading category since 2020.

Meanwhile, compact vehicles declined from 28.5% to 25.4% of vehicles on the road, and sedans and minivans fell from 19.7% to 14.6%.

With their heavy batteries, EVs in Quebec now weigh about 23% more than gas-powered vehicles, or an extra 344 kg.

Heavier vehicles also take a toll in terms of premature wear and tear on the roads and more serious injuries in accidents. And as they continue to get heavier, they also put a strain on Quebec’s power grid.

Between 2021 and 2040, the UdeM researchers project that the amount of electricity used by EVs in the province will increase from 0.24 terawatt hours (TWh) to 29.03 TWh.

Harsh winters increase demand

EVs accounted for about 13.6% of Quebec’s total electricity demand in 2019. By 2030, when the government aims to have two million EVs on the roads, EV consumption would reach 7.68 TWh.

That’s roughly consistent with Hydro-Québec’s projection of 7.8 TWh for 2032.

However, Mousseau is concerned about the grid’s capacity in the province’s harsh winter months, when cold spells can be protracted and extreme.

EVs use more power in winter than in summer because cold temperatures reduce battery efficiency, increase tire friction and increase air density.

In January, when the average temperature is -10.3°C, monthly EV consumption will rise to 3.1 TWh once Quebec’s vehicle fleet is fully electrified, compared with 1.9 TWh in August, the UdeM researchers project.

At -20°C, the required capacity is almost double that on a summer day.

“In winter, we need to control electricity usage because adding capacity to meet peak demand costs $150 to $200 per kilowatt,” Mousseau said.

“With a fully electrified fleet in 2040, EVs would require an average additional capacity of 5,261 megawatts when the temperature is -20°C. That’s 12.1% of the total peak demand recorded in 2022.

“If the increasing weight of the EV fleet adds another gigawatt to peak demand, it will cost hundreds of millions of dollars more to generate that electricity.”

Three possible scenarios

The researchers modeled three scenarios for the period 2021-2040.

In the first, they allow the trend toward heavier vehicles to continue without intervention. In this case, the average mass would increase to 2,114 kg by 2040. The fleet’s annual electricity consumption would increase to 29.03 TWh and the additional required capacity on a cold winter’s day would be 5,261 megawatts.

In the second scenario, the increase in weight is limited to the weight of the EV battery: on average in Quebec, about 344 kg.

In the third scenario, the average vehicle weight is frozen at the 2021 level of 1,566 kg. This would reduce EV electricity demand by 17.6% in 2040, from 29.03 to 23.91 TWh. The required capacity on a -20°C day would drop from 5,261 to 4,332 megawatts.

The saving of almost 6 TWh is equivalent to three percent of Hydro-Québec’s current total production. It would avoid the need to build costly infrastructure that would be needed only for a few hours a year, during winter peaks.

In scenario 1, by 2035, EVs will require additional capacity of 3,232 megawatts when the temperature is -20°C. That is 40.4% of all the additional power projected in Hydro-Québec’s action plan by 2035.

“Electrification of the vehicle fleet will entail system costs that will have to be borne,” said Mousseau. “We believe that reducing the average weight of vehicles is one solution that should be explored.”

Regulations could make batteries lighter

How can the weight of EVs be reduced? The researchers suggest several possibilities.

One is to reduce the weight of the battery, a significant technological challenge but one they believe is achievable with technological progress.

“Between 2017-2018 and 2021-2022, batteries were improved to increase range, but unfortunately, this improvement also increased the weight of the vehicles,” Mousseau said.

The simplest solution would be to amend the existing “Act to increase the number of zero-emission motor vehicles in Québec,” he suggested.

“Manufacturers could be required to comply with a specific average weight, or to offset the additional weight by paying a fine or tax.”

This approach, which has proven effective in stimulating the production of EVs, could also be used to control their weight, Mousseau said.

“For example, Tesla has benefited from the credit transfers allowed by the Act, demonstrating that it is possible to have manufacturers, not consumers, bear the cost of design choices.”

‘Strong global pressure’

Although the Quebec government recently backtracked on banning the sale of gasoline-powered vehicles by 2035, Mousseau is confident about the future of electrification.

“There is strong global pressure: the electrification of road vehicles will happen,” he said.

By postponing electrification, “Quebec is temporarily burying its head in the sand, but it cannot indefinitely block access to more efficient and less expensive electric vehicles, such as those made in China.”

Mousseau also pointed to an important economic issue: “For 20 years, we have watched other countries develop green technologies. What will we be producing 20 years from now, if we keep letting others take the lead? If we don’t put our foot on the accelerator, there’ll be significant economic risks.”

When writing program code, software developers often work in pairs—a practice that reduces errors and encourages knowledge sharing. Increasingly, AI assistants are now being used for this role.

But this shift in working practice isn’t without its drawbacks, as a new empirical study by computer scientists in Saarbrücken reveals. Developers tend to scrutinize AI-generated code less critically and they learn less from it. These findings will be presented at the 40th IEEE/ACM International Conference on Automated Software Engineering (ASE 2025) in Seoul.

When two software developers collaborate on a programming project—known in technical circles as pair programming—it tends to yield a significant improvement in the quality of the resulting software.

“Developers can often inspire one another and help avoid problematic solutions. They can also share their expertise, thus ensuring that more people in their organization are familiar with the codebase,” explains Sven Apel, professor of computer science at Saarland University.

Together with his team, Apel has examined whether this collaborative approach works equally well when one of the partners is an AI assistant. In the study, 19 students with programming experience were divided into pairs: Six worked with a human partner, while seven collaborated with an AI assistant. The methodology for measuring knowledge transfer was developed by Niklas Schneider as part of his bachelor’s thesis.

For the study, the researchers used GitHub Copilot, an AI-powered coding assistant introduced by Microsoft in 2021, which—like similar products from other companies—has now been widely adopted by software developers. These tools have significantly changed how software is written.

“It enables faster development and the generation of large volumes of code in a short time. But this also makes it easier for mistakes to creep in unnoticed, with consequences that may only surface later on,” says Apel. The team wanted to understand which aspects of human collaboration enhance programming and whether these can be replicated in human-AI pairings. Participants were tasked with developing algorithms and integrating them into a shared project environment.

“Knowledge transfer is a key part of pair programming,” Apel explains. “Developers will continuously discuss current problems and work together to find solutions. This does not involve simply asking and answering questions, it also means that the developers share effective programming strategies and volunteer their own insights.”

According to the study, such exchanges also occurred in the AI-assisted teams—but the interactions were less intense and covered a narrower range of topics.

“In many cases, the focus was solely on the code,” says Apel. “By contrast, human programmers working together were more likely to digress and engage in broader discussions and were less focused on the immediate task.”

One finding particularly surprised the research team: “The programmers who were working with an AI assistant were more likely to accept AI-generated suggestions without critical evaluation. They assumed the code would work as intended,” says Apel. “The human pairs, in contrast, were much more likely to ask critical questions and were more inclined to carefully examine each other’s contributions.”

He believes this tendency to trust AI more readily than human colleagues may extend to other domains as well, stating, “I think it has to do with a certain degree of complacency—a tendency to assume the AI’s output is probably good enough, even though we know AI assistants can also make mistakes.

Apel warns that this uncritical reliance on AI could lead to the accumulation of “technical debt,” which can be thought of as the hidden costs of the future work needed to correct these mistakes, thereby complicating the future development of the software.

For Apel, the study highlights the fact that AI assistants are not yet capable of replicating the richness of human collaboration in software development.

“They are certainly useful for simple, repetitive tasks,” says Apel. “But for more complex problems, knowledge exchange is essential—and that currently works best between humans, possibly with AI assistants as supporting tools.”

Apel emphasizes the need for further research into how humans and AI can collaborate effectively while still retaining the kind of critical eye that characterizes human collaboration.

A fermentation byproduct might help to solve two major global challenges: world hunger and the environmental impact of fast fashion. The leftover yeast from brewing beer, wine or even to make some pharmaceuticals can be repurposed to produce high-performance fibers stronger than natural fibers with significantly less environmental impact, according to a new study led by researchers at Penn State and published in the Proceedings of the National Academy of Sciences.

The yeast biomass—composed of proteins, fatty molecules called lipids and sugars—left over from alcohol and pharmaceutical production is regarded as waste, but lead author Melik Demirel, Pearce Professor of Engineering and Huck Chair in Biomimetic Materials at Penn State, said his team realized they could repurpose the material to make fibers using a previously developed process.

The researchers successfully achieved pilot-scale production of the fiber—producing more than 1,000 pounds—in a factory in Germany, with continuous and batch production for more than 100 hours per run of fiber spinning.

They also used data collected during this production for a lifecycle assessment, which assessed the needs and impact of the product from obtaining the raw fermentation byproduct through its life to disposal and its cost, and to evaluate the economic viability of the technology. The analysis predicted the cost, water use, production output, greenhouse gas emissions and more at every stage.

Ultimately, the researchers found that the commercial-scale production of the fermentation-based fiber could compete with wool and other fibers at scale but with considerably fewer resources, including far less land—even when accounting for the land needed to grow the crops used in the fermentation processes that eventually produce the yeast biomass.

“Just as hunter-gatherers domesticated sheep for wool 11,000 years ago, we’re domesticating yeast for a fiber that could shift the agricultural lens to focus far more resources to food crops,” said Demirel, who is also affiliated with the Materials Research Institute and the Institute of Energy and the Environment, both at Penn State.

“We successfully demonstrated that this material can be made cheaply—for $6 or less per kilogram, which is about 2.2 pounds, compared to wool’s $10 to $12 per kilogram—with significantly less water and land but improved performance compared to any other natural or processed fibers, while also nearly eliminating greenhouse gas emissions. The saved resources could be applied elsewhere, like repurposing land to grow food crops.”

Waste not, want not

Demirel’s team has spent over a decade developing a process to produce a fiber from proteins. Inspired by nature, the fiber is durable and free of the chemicals other fibers can leave in the environment for years.

“We can pull the proteins as an aggregate—mimicking naturally occurring protein accumulations called amyloids—from the yeast, dissolve the resulting pulp in a solution, and push that through a device called a spinneret that uses tiny spigots to make continuous fibers,” Demirel said, explaining the fibers are then washed, dried and spun into yarn that can then be woven into fabric for clothes.

He also noted that the fibers are biodegradable, meaning they would break down after disposal, unlike the millions of tons of polyester clothing discarded every year that pollutes the planet.

“The key is the solution used to dissolve the pulp. This solvent is the same one used to produce Lyocell, the fiber derived from cellulose, or wood pulp. We can recover 99.6% of the solvent used to reuse it in future production cycles.”

The idea of using proteins to make fiber is not new, according to Demirel, who pointed to Lanital as an example. The material was developed in the 1930s from milk protein, but it fell out of fashion due to low strength with the advent of polyester.

“The issue has always been performance and cost,” Demirel said, noting the mid-20th century also saw the invention of fibers made from peanut proteins and from corn proteins before cheap and stronger polyester ultimately reigned.

Freeing land from fiber to produce food

Beyond producing a quality fiber, Demirel said, the study also indicated the fiber’s potential on a commercial scale. The models rolled their pilot-scale findings into simulated scenarios of commercial production. For comparison, about 55,000 pounds of cotton are produced globally every year and just 2.2 pounds—about what it takes to make one T-shirt and one pair of jeans—requires up to 2,642 gallons of water. Raw cotton is relatively cheap, Demirel said, but the environmental cost is staggering.

“Cotton crops also use about 88 million acres, of farmable land around the world—just under 40% of that is in India, which ranks as ‘serious’ on the Global Hunger Index,” Demirel said.

“Imagine if instead of growing cotton, that land, water, resources and energy could be used to produce crops that could feed people. It’s not quite as simple as that, but this analysis demonstrated that biomanufactured fibers require significantly less land, water and other resources to produce, so it’s feasible to picture how shifting from crop-based fibers could free up a significant amount of land for food production.”

In 2024, 733 million people—about one in 12—around the world faced food insecurity, a continued trend that has led the United Nations to declare a goal of Zero Hunger to eliminate this issue by 2030. One potential solution may be to free land currently used to grow fiber crops to produce more food crops, according to Demirel.

Current production methods not only use significant resources, he said, but more than 66% of clothing produced annually in the U.S. alone ends up in landfills. Demirel’s approach offers a solution for both problems, he said.

“By leveraging biomanufacturing, we can produce sustainable, high-performance fibers that do not compete with food crops for land, water or nutrients,” Demirel said. “Adopting biomanufacturing-based protein fibers would mark a significant advancement towards a future where fiber needs are fulfilled without compromising the planet’s capacity to nourish its growing population. We can make significant strides towards achieving the Zero Hunger goal, ensuring everyone can access nutritious food while promoting sustainable development goals.”

Future of fiber

Demirel said the team plans to further investigate the viability of fermentation-based fibers at a commercial scale.

The team includes Benjamin Allen, chief technology officer, and Balijit Ghotra, Tandem Repeat Technologies, Inc., the spin-off company founded by Demirel and Allen based on this fiber production approach. The work has a patent pending, and the Penn State Office of Technology Transfer licensed the technology to Tandem Repeat Technologies. Other co-authors include Birgit Kosan, Philipp Köhler, Marcus Krieg, Christoph Kindler and Michael Sturm, all with the Thüringisches Institut für Textil- und Kunststoff-Forschung (TITK) e. V. in Germany.

“In my lab at Penn State, we demonstrated we could physically make the fiber,” Demirel said. “In this pilot production at the factory, together with Tandem and TITK, we demonstrated we could make the fiber a contender in the global fiber market. Sonachic, an online brand formed by Tandem Repeat, makes this a reality. Next, we will bring it to mass market.”