CO2 emissions from gas cars outweigh electric, even with battery manufacturing | Fact check

Kate S. Petersen, USA TODAY
·8 min read
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The claim: Manufacturing electric car battery creates the same CO2 as driving a gas car for 8 years

A Nov. 30, 2023, Facebook post (direct link, archive link) compares purported CO2 emissions from electric car battery manufacturing to those produced by gas-powered cars.

"Cool stat," reads the post. "Manufacturing JUST the battery for an electric car produces the same amount of CO2 as a gas engine does in 8 years!!"

The post was shared more than 3,000 times in six weeks.

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Our rating: False

Electric car battery manufacturing does produce CO2 emissions, but there is no set number of years it takes gas engine emissions to match those produced by battery manufacturing. Instead, it depends on a variety of factors such as the battery manufacturing processes, the size of the EV battery and how much the gas car is driven.

Assuming average driving patterns and gas car tailpipe emissions, data from the latest studies shows it takes far less than eight years of gas car driving to match CO2 emissions from an EV battery in Australia (where this claim originated) or the U.S.

What is the carbon footprint of making an EV battery?

There have been many studies that estimate emissions from EV battery manufacturing. These often report emissions generated per kilowatt hour (kWh) − a measure of battery size. For instance:

All of these estimates taken together yield a range of 90-220 pounds of CO2 equivalent greenhouse gases per kWh. If these values are applied to a 60-90 kWh EV battery (common sizes sold in the U.S. in 2022), the result is a range of around 2.5-9 metric tons of CO2-equivalent emissions per battery.

The amount of CO2 produced per mile during gas vehicle operation also varies depending on the vehicle's fuel efficiency, but the U.S. average is 400 grams per mile, according to the U.S. Environmental Protection Agency. Based on this estimate, gas vehicle tailpipe emissions would equal emissions from battery manufacturing at between 6,250-22,500 miles driven.

The amount of time it would take to reach that mileage would depend on driver habits. However, the average American driver travels 13,476 miles annually, according to the U.S. Department of Transportation.

Based on this estimate, emissions from a gas vehicle would match those of an EV battery after around 6-20 months, far less than eight years.

In Australia (the listed residence of the Facebook user who posted the claim) the average vehicle is driven around 7,519 miles per year, according to the Australian Bureau of Statistics. All other estimates being the same, it would take about 10-36 months for emissions from the gas car to match those of the battery.

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Some past studies have reported much higher estimated greenhouse gas emissions associated with EV battery manufacturing. For instance, the highest estimate reviewed by USA TODAY was 427-1089 pounds of CO2 equivalent per kWh, which appeared in a 2016 paper.

Assuming the same estimates from the previous calculations, it would take slightly more than eight years of driving in the U.S. to match manufacturing emissions of 1,089 per kWH for a 90 kWh battery. However, that is not currently a realistic scenario, Hanjiro Ambrose, the lead author of the 2016 paper, told USA TODAY in an email.

He said there have been broad changes in battery manufacturing scale, efficiency and technologies since the 2016 paper was published and that much lower emissions − around roughly 220 pounds per kWh − are more realistic. This estimate fits within the range of values USA TODAY used to compare EV battery manufacturing emissions to gas car tailpipe emissions.

Georg Bieker, a senior researcher at the International Council on Clean Transportation, told USA TODAY that contemporary emissions research benefits from real-world data that wasn't previously available for studies more than a few years old. In the past, energy consumption patterns by large battery manufacturing facilities could only be approximated.

However, with "global battery production growing, the energy consumption in real production plants became available and it turned out that the earlier estimates were way too high," he said in an email. "In current large-scale battery production plants of several gigawatt hours of battery capacity per year − gigafactories − the energy consumption per single battery is much lower than in lab or pilot production plants the earlier estimates were based on."

Bieker said the estimate in his 2021 paper − 132 pounds per kWh for batteries sold in the U.S. − was based on real-world data. Data from this paper was included in USA TODAY's comparison of emissions from battery manufacturing and gas vehicle engines.

Electric vehicle lifetime emissions typically lower than gas-powered vehicles

The Facebook post makes a misleading claim about EV batteries and, by focusing on only two sources of emissions, it also fails to provide a complete comparison of the two technologies. For instance, gas vehicle manufacturing also produces CO2 emissions.

"It’s important to look at the entire vehicle and fuel lifecycles − not just how much energy or emissions are associated with one portion," Matteo Muratori, a transportation energy transition researcher at National Renewable Energy Laboratory, told USA TODAY in an email.

Thus, when researchers are comparing emissions from the two technologies, they examine "lifecycle emissions" − all of the emissions associated with each phase of the vehicle's lifetime. These include greenhouse gas emissions from:

  • Mining

  • Transportation of raw materials

  • Vehicle manufacturing, including battery manufacturing

  • The production and distribution of gasoline

  • Gasoline combustion in a gas engine

  • Electricity generation for electric vehicle charging

When full lifecycle emissions are taken into account, most EVs emit significantly less CO2 than comparable gas vehicles, Jessika Trancik, a Massachusetts Institute of Technology professor who studies electric vehicle emissions, previously told USA TODAY.

"The lifecycle emissions of an electric vehicle are typically more than 30% lower than those of a comparable gas-powered car – across most car models and locations" (in the U.S.), she said in an email. "This difference will increase as the electricity mix decarbonizes."

Decarbonization of the U.S. electric grid – using more renewable energy sources and fewer fossil fuels – is necessary for the emissions reduction benefits of EVs to be fully realized, according to Carbon Brief.

Currently, the electric grid in the U.S. is powered by a relatively high proportion of fossil fuels, which contributes significantly to EV emissions. Sixty percent of grid power came from coal, natural gas and petroleum in 2022, according to the U.S. Energy Information Administration.

When fossil fuels make up a larger percentage of the energy mix, it is possible for an EV with a battery produced under particularly carbon emissions-intensive conditions to have a lifecycle carbon footprint similar to a hybrid vehicle (though it would still have a lower footprint than a standard car), according to Carbon Brief.

However, while wind and solar only generated 13.6% of grid power in 2022, they are projected to provide 44% by 2050, according to the Energy Information Administration.

"There are paths for EV emissions − which are already lower than those of gasoline vehicles − to further reduce over time, while gasoline vehicles will continue to have similar emissions forever," Muratori said. "In about 10 years, we estimate that EVs will ... emit about 80% less than a future advanced gasoline vehicle."

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USA TODAY reached out to the Facebook user who shared the post for comment but did not receive a response.

The claim was also debunked by PolitiFact and Australian Associated Press.

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This article originally appeared on USA TODAY: Electric car battery v. gas engine CO2 claim misleads | Fact check