Electric cars are better for the environment, no matter the power source
Experts say that across the board, EVs are a win compared to similar gas-powered vehicles.
These days, it seems like every carmaker—from those focused on luxury options to those with an eye more toward the economical—is getting into electric vehicles. And with new US policies around purchasing incentives and infrastructure improvements, consumers might be more on board as well. But many people are still concerned about whether electric vehicles are truly better for the environment overall, considering certain questions surrounding their production process.
Despite concerns about the pollution generated from mining materials for batteries and the manufacturing process for the EVs themselves, the environmental and energy experts PopSci spoke to say that across the board, electric vehicles are still better for the environment than similar gasoline or diesel-powered models.
When comparing a typical commercial electric vehicle to a gasoline vehicle of the same size, there are benefits across many different dimensions.
“We do know, for instance, if we’re looking at carbon dioxide emissions, greenhouse gas emissions, that electric vehicles operating on the typical electric grid can end up with fewer greenhouse gas emissions over the life of their vehicle,” says Dave Gohlke, an energy and environmental analyst at Argonne National Lab. “The fuel consumption (using electricity to generate the fuel as opposed to burning petroleum) ends up releasing fewer emissions per mile and over the course of the vehicle’s expected lifetime.”
[Related: An electrified car isn’t the same thing as an electric one. Here’s the difference.]
How the electricity gets made
With greenhouse gas emissions, it’s also worth considering how the electricity for charging the EV is generated. Electricity made by a coal- or oil-burning plant will have higher emissions compared to a natural gas plant, while nuclear and renewable energy will have the fewest emissions. But even an electric vehicle that got its juice from a coal plant tends to have fewer emissions compared to a gasoline vehicle of the same size, Gohlke says. “And that comes down to the fact that a coal power plant is huge. It’s able to generate electricity at a better scale, [be] more efficient, as opposed to your relatively small engine that fits in the hood of your car.” Power plants could additionally have devices in place to scrub their smokestacks or capture some of the emissions that arise.
EVs also produce no tailpipe emissions, which means reductions in particulate matter or in smog precursors that contribute to local air pollution.
“The latest best evidence right now indicates that in almost everywhere in the US, electric vehicles are better for the environment than conventional vehicles,” says Kenneth Gillingham, professor of environmental and energy economics at Yale School of the Environment. “How much better for the environment depends on where you charge and what time you charge.”
Electric motors tend to be more efficient compared to the spark ignition engine used in gasoline cars or the compression ignition engine used in diesel cars, where there’s usually a lot of waste heat and wasted energy.
Let’s talk about EV production
“It’s definitely the case that any technology has downsides. With technology you have to use resources, [the] raw materials we have available, and convert them to a new form,” says Jessika Trancik, a professor of data, systems, and society at the Massachusetts Institute of Technology. “And that usually comes with some environmental impacts. No technology is perfect in that sense, but when it comes to evaluating a technology, we have to think of what services it’s providing, and what technology providing the same service it’s replacing.”
Creating an EV produces pollution during the manufacturing process. “Greenhouse gas emissions associated with producing an electric vehicle are almost twice that of an internal combustion vehicle…that is due primarily to the battery. You’re actually increasing greenhouse gas emissions to produce the vehicle, but there’s a net overall lifecycle benefit or reduction because of the significant savings in the use of the vehicle,” says Gregory Keoleian, the director of the Center for Sustainable Systems at the University of Michigan. “We found in terms of the overall lifecycle, on average, across the United States, taking into account temperature effects, grid effects, there was 57 percent reduction in greenhouse gas emissions for a new electric vehicle compared to a new combustion engine vehicle.”
In terms of reducing greenhouse gas emissions associated with operating the vehicles, fully battery-powered electric vehicles were the best, followed by plug-in hybrids, and then hybrids, with internal combustion engine vehicles faring the worst, Keoleian notes. Range anxiety might still be top of mind for some drivers, but he adds that households with more than one vehicle can consider diversifying their fleet to add an EV for everyday use, when appropriate, and save the gas vehicle (or the gas feature on their hybrids) for longer trips.
The breakeven point at which the cost of producing and operating an electric vehicle starts to gain an edge over a gasoline vehicle of similar make and model occurs at around two years in, or around 20,000 to 50,000 miles. But when that happens can vary slightly on a case-by-case basis. “If you have almost no carbon electricity, and you’re charging off solar panels on your own roof almost exclusively, that breakeven point will be sooner,” says Gohlke. “If you’re somewhere with a very carbon intensive grid, that breakeven point will be a little bit later. It depends on the style of your vehicle as well because of the materials that go into it.”
[Related: Why solid-state batteries are the next frontier for EV makers]
For context, Gohlke notes that the average EV age right now is around 12 years old based on registration data. And these vehicles are expected to drive approximately 200,000 miles over their lifetime.
“Obviously if you drive off your dealer’s lot and you drive right into a light pole and that car never takes more than a single mile, that single vehicle will have had more embedded emissions than if you had wrecked a gasoline car on your first drive,” says Gohlke. “But if you look at the entire fleet of vehicles, all 200-plus-million vehicles that are out there and how long we expect them to survive, over the life of the vehicle, each of those electric vehicles is expected to consume less energy and emit lower emissions than the corresponding gas vehicle would’ve been.”
To put things in perspective, Gillingham says that extracting and transporting fossil fuels like oil is energy intensive as well. When you weigh those factors, electric vehicle production doesn’t appear that much worse than the production of gasoline vehicles, he says. “Increasingly, they’re actually looking better depending on the battery chemistry and where the batteries are made.”
And while it’s true that there are issues with mines, the petrol economy has damaged a lot of the environment and continues to do so. That’s why improving individual vehicle efficiency needs to be paired with reducing overall consumption.
EV batteries are getting better
Mined materials like rare metals can have harmful social and environmental effects, but that’s an economy-wide problem. There are many metals that are being used in batteries, but the use of metals is nothing new, says Trancik. Metals can be found in a range of household products and appliances that many people use in their daily lives.
Plus, there have been dramatic improvements in battery technology and the engineering of the vehicle itself in the past decade. The batteries have become cheaper, safer, more durable, faster charging, and longer lasting.
“There’s still a lot of room to improve further. There’s room for improved chemistry of the batteries and improved packaging and improved coolant systems and software that manages the batteries,” says Gillingham.
The two primary batteries used in electric vehicles today are NMC (nickel-manganese-cobalt) and LFP (lithium-ferrous-phosphate). NMC batteries tend to use more precious metals like cobalt from the Congo, but they are also more energy dense. LFP uses more abundant metals. And although the technology is improving fast, it’s still in an early stage, sensitive to cold weather, and not quite as energy dense. LFP tends to be good for utility scale cases, like for storing electricity on the grid.
[Related: Could swappable EV batteries replace charging stations?]
Electric vehicles also offer an advantage when it comes to fewer trips to the mechanic; conventional vehicles have more moving parts that can break down. “You’re more likely to be doing maintenance on a conventional vehicle,” says Gillingham. He says that there have been Teslas in his studies that are around eight years old, with 300,000 miles on them, which means that even though the battery does tend to degrade a little every year, that degradation is fairly modest.
Eventually, if the electric vehicle markets grow substantially, and there’s many of these vehicles in circulation, reusing the metals in the cars can increase their benefits. “This is something that you can’t really do with the fossil fuels that have already been combusted in an internal combustion engine,” says Trancik. “There is a potential to set up that circularity in the supply chain of those metals that’s not readily done with fossil fuels.”
Since batteries are fairly environmentally costly, the best case is for consumers who are interested in EVs to get a car with a small battery, or a plug-in hybrid electric car that runs on battery power most of the time. “A Toyota Corolla-sized car, maybe with some hybridization, could in many cases, be better for the environment than a gigantic Hummer-sized electric vehicle,” says Gillingham. (The charts in this New York Times article help visualize that distinction.)
Where policies could help
Electric vehicles are already better for the environment and becoming increasingly better for the environment.
The biggest factor that could make EVs even better is if the electrical grid goes fully carbon free. Policies that provide subsidies for carbon-free power, or carbon taxes to incentivize cleaner power, could help in this respect.
The other aspect that would make a difference is to encourage more efficient electric vehicles and to discourage the production of enormous electric vehicles. “Some people may need a pickup truck for work. But if you don’t need a large car for an actual activity, it’s certainly better to have a more reasonably sized car,” Gillingham says.
Plus, electrifying public transportation, buses, and vehicles like the fleet of trucks run by the USPS can have a big impact because of how often they’re used. Making these vehicles electric can reduce air pollution from idling, and routes can be designed so that they don’t need as large of a battery.
“The rollout of EVs in general has been slower than demand would support…There’s potentially a larger market for EVs,” Gillingham says. The holdup is due mainly to supply chain problems.
Switching over completely to EVs is, of course, not the end-all solution for the world’s environmental woes. Currently, car culture is very deeply embedded in American culture and consumerism in general, Gillingham says, and that’s not easy to change. When it comes to climate policy around transportation, it needs to address all the different modes of transportation that people use and the industrial energy services to bring down greenhouse gas emissions across the board.
The greenest form of transportation is walking, followed by biking, followed by using public transit. Electrifying the vehicles that can be electrified is great, but policies should also consider the ways cities are designed—are they walkable, livable, and have a reliable public transit system connecting communities to where they need to go?
“There’s definitely a number of different modes of transport that need to be addressed and green modes of transport that need to be supported,” says Trancik. “We really need to be thinking holistically about all these ways to reduce greenhouse gas emissions.”
