[Reading Science]Are Electric Vehicles Truly Eco-Friendly?...①Science Calculates the ‘Lifetime’ of a Car

Life Cycle Assessment: From Battery Production to Operation and Disposal

Electric Vehicles at a Disadvantage at Purchase, But Overtake in Carbon Savings Over Time

Editor's Note'Science Scope' is a special feature that takes an in-depth look at specific science and technology phenomena, analyzing their meaning and future implications.

Electric vehicles emit no exhaust gases when running. Since they don’t burn gasoline or diesel in an engine, there is no carbon dioxide emitted while driving. Does this make electric vehicles the “perfect eco-friendly cars”?

The carbon footprint of a car is not limited to what happens on the road. Carbon is already released during the process of producing the body and components and assembling the vehicle. Additionally, the mining and refining of battery materials such as lithium, nickel, and cobalt, as well as the production of battery cells, must be considered. Power plants generating the electricity used for charging also emit greenhouse gases. The processes of vehicle scrapping and battery disposal have environmental impacts as well. In other words, even if the exhaust emissions are “zero,” it does not mean that overall carbon emissions are also “zero.”

Hyundai Motor Group Kona EV test drive event. To evaluate the environmental impact of electric vehicles, it is necessary to examine the entire process from vehicle and battery production to disposal and recycling, as well as driving. Provided by Hyundai Motor Group.

Lee Sora, Senior Research Fellow at the Circular Economy Research Group of the Korea Environment Institute, explained, “Electric vehicles do not emit exhaust gases on the road, but that is only one stage in the vehicle’s life cycle—the operational stage. In reality, environmental impact is created throughout the entire cycle, from raw material extraction, parts and battery and vehicle manufacturing, electricity generation and charging, operation, and disposal and recycling.”

The method of quantifying all environmental impacts arising from raw material extraction, manufacturing, use, and the process of disposal or recycling is called the “Life Cycle Assessment (LCA).” It involves analyzing the car’s entire “lifetime” from birth to scrapping as a single unit of analysis.

Even with 'Zero' Exhaust, Carbon Emissions Are Not 'Zero'

Measuring gases emitted by vehicles while running is referred to as “Tank-to-Wheel (TTW).” While internal combustion engine vehicles emit carbon dioxide by burning fuel, electric vehicles have direct emissions of zero at this stage.

When including crude oil extraction, transportation, refining, and power generation, the scope is called “Well-to-Wheel (WTW).” LCA goes even further to include raw material extraction and manufacturing for vehicles and batteries, operation, scrapping, and recycling. Even among electric vehicles, the environmental scorecard can vary depending on where and using what power the battery was made, what energy is used for charging, and how long the car is in operation.

The initial phase for electric vehicles is not necessarily favorable on the environmental scorecard. At the point of leaving the factory, electric vehicles may have already released more carbon than internal combustion engine cars.

The main cause is the battery. Mining and refining battery minerals and producing cathode, anode, and battery cells require substantial energy. If battery factories use power heavily reliant on fossil fuels, carbon emissions during the production phase increase even more.

Battery capacity also plays a role. Larger batteries require more materials and energy, and add weight to the car. This is why it is not appropriate to evaluate all electric vehicles, from compact models to large electric SUVs, the same just because they are all electric.

According to analysis by the International Council on Clean Transportation (ICCT), for mid-sized passenger cars sold in the European Union (EU) in 2025, battery electric vehicles emitted about 40% more greenhouse gases during the production stage than gasoline vehicles. However, the reverse was true over the entire life cycle: electric vehicles had emissions of 63gCO₂e/km, which is 73% lower than gasoline cars (235gCO₂e/km).

This is because after vehicles are delivered, the pattern of carbon accumulation changes. Internal combustion engine vehicles emit carbon dioxide whenever fuel is burned. In contrast, electric vehicles have no direct emissions while driving; instead, most emissions come from the power used for charging. As the electric grid is decarbonized, the indirect emissions of electric cars already on the road can be reduced as well.

The International Energy Agency (IEA) analyzed that, based on global averages, a mid-sized battery electric vehicle sold in 2023 and operated for 200,000 km over 15 years would have less than half the life cycle greenhouse gas emissions of a similar internal combustion engine vehicle, and more than 40% lower than a hybrid vehicle.

Turnaround After 17,000 km... The ‘Carbon Payback Point’

The point at which additional carbon released during battery production is offset through operation of an electric car is commonly called the “Carbon Payback Point.”

In the ICCT’s 2025 analysis, for mid-sized electric cars sold in the EU, this offset point was reached at around 17,000 km, when the excess greenhouse gases emitted during production compared to gasoline cars were made up for through lower emissions during use. After that, the longer the distance driven, the greater the gap in cumulative emissions. Of course, “17,000 km” is not a universal number for all electric vehicles: it was derived using average EU power mix, vehicle and battery production conditions, among other factors.

In regions with a high proportion of fossil fuel power generation, reaching the carbon payback point could be delayed. Conversely, in places where low-carbon electricity is prevalent, the payback can be achieved sooner. Factors such as battery size and manufacturing method, vehicle lifespan, and total driving distance also affect the result.

Senior Research Fellow Lee explained, “Electric vehicles emit more greenhouse gases during manufacturing but much less during driving. The longer the vehicle’s total driving distance, the more the initial production emissions are offset, resulting in an overall advantage. Conversely, if an electric vehicle is made with an exceptionally large battery, or is scrapped after only a short time on the road, the carbon payback point might not be reached.”

If a battery replacement is needed during the lifetime of the electric vehicle, the calculations change, since a new battery must be produced. Recent studies have revisited the assumption that battery lifespan is shorter than the vehicle’s own lifetime.

Research cited by the ICCT in its 2025 report shows that nickel-manganese-cobalt (NMC) batteries can withstand between 3,000 and 5,000 full charge-discharge cycles while retaining over 80% of their initial capacity. Lithium iron phosphate (LFP) batteries surpassed 5,000 to 6,000 cycles. Assuming a single-charge driving range of 200 to 400 km, NMC batteries, with 3,000 to 5,000 cycles, correspond to a rough estimate of 600,000 to 2 million km.

Real-world usage data is similar. In the ICCT-cited survey of 20,000 electric cars, the battery replacement rate for vehicles sold after 2016 (excluding recall cases) was under 1%. Based on current research, the ICCT concluded that lithium-ion batteries typically outlast the vehicles themselves.

How long a battery can be used becomes another key factor in determining an electric vehicle’s “lifetime environmental scorecard.”

Electric Cars Also Have Lower Carbon Emissions in Korea... “But It’s Not 100 to 0”

Researchers An Jaeyeon and Lee Juha from Ewha Womans University, along with Kim Jarung, Head of Future Vehicle Research at the Korea Transportation Safety Authority, and Professor Choi Wonjae from Ewha Womans University’s School of Human-Machine Bioengineering, compared the life cycle greenhouse gas emissions of internal combustion engine vehicles, hybrids, electric vehicles, and hydrogen electric vehicles, as published in the 2025 edition of the Korean Hydrogen and New Energy Society Journal.

The research team compared Hyundai’s Kona models: the Kona internal combustion engine, Kona hybrid, and Kona Electric, as well as analyzing the Nexo hydrogen electric vehicle. Including everything from fuel and electricity production to vehicle and battery manufacturing, disposal, and direct emissions during driving, electric vehicles had higher emissions than internal combustion and hybrid vehicles during the production and disposal stages due to the impact of battery manufacturing.

On the other hand, electric vehicles emit no direct greenhouse gases during operation. Although greenhouse gases are produced during electricity generation for charging, the total life cycle emissions, including this, were still lower than those of internal combustion engine and hybrid vehicles.

Professor Choi explained, “When vehicle production and scrapping are considered, the difference in life cycle greenhouse gas emissions between hybrids and electric vehicles narrows. The main reason is the significant greenhouse gases released during battery production.”

He added, however, “Even in Korea, the greenhouse gas emissions of electric vehicles are on the lower side compared to hybrids. However, the gap is not as dramatic as 100 to 0, as the general public may assume.”

Electric vehicles and other export vehicles are waiting to be loaded at Pyeongtaek Port in Gyeonggi Province. Photo by Yonhap News Agency

This explains why various studies report differing carbon reduction effects from electric vehicles. Changes in vehicle size, battery capacity, lifespan, total driving distance, carbon intensity of electricity, and assessment scope all influence the results.

Professor Choi emphasized, “Rather than uncritically deciding that one type of vehicle is better, we must objectively compare whole-life-cycle greenhouse gas emissions to see which vehicle emits less under which conditions.”

The research team is also conducting studies applying this life cycle assessment methodology to real-world vehicle environmental evaluations. With support from the Ministry of Land, Infrastructure, and Transport and led by the Korea Transportation Safety Authority, the “Korean Green NCAP Evaluation Technology Development” project is developing technology to measure whole-life-cycle environmental impacts, covering not just vehicle operation but also fuel and power production and vehicle manufacturing.

Life cycle assessment is neither a tool designed to prove that electric vehicles are environmentally friendly, nor a tool to conclude, due to battery production carbon, that they are not eco-friendly. Rather, it is a method for comparing the environmental burdens left by different vehicles after birth and before disappearance, under equivalent conditions.

So what about Korea, where coal and natural gas power still account for a significant share of electricity generation? The real environmental scorecard for electric vehicles is determined as much by what happens outside the car, in the power plants generating the electricity, as by the operation of the vehicle itself.

This content was produced with the assistance of AI translation services.