Electric cars claim to be cheaper and greener. But are they?

Electric cars claim to be cheaper and greener. But are they?
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Does it really make sense to replace your gas car with an electric one? We can help you decide, taking two key factors into consideration: cost and environmental impact.

We’ve calculated the overall cost of a car over its lifetime. That includes the upfront purchase price, annual maintenance costs, and gas in the case of a gasoline-powered car or the cost of charging batteries for electric vehicles. This analysis is adapted from the total-cost-of-ownership model developed by researchers at the International Energy Agency (IEA).1

Most electric cars are more expensive to purchase but cheaper to maintain than gasoline-powered cars. This makes electric cars especially attractive for someone who regularly drives long distances, like drivers in the US, or lives in a place where gas is expensive, like in most western European countries.

The reason most electric cars have high upfront costs is because of the battery. Even with cutting-edge technology and large-scale production, the cost of batteries hasn’t yet fallen enough to make electric cars cheaper than those with internal-combustion engines. Some believe that might happen as soon as 2025.

For now, that’s why governments around the world offer subsidies or tax exemptions to buyers of new electric cars. Those have proven to be the most effective levers for boosting EV sales, according to the IEA’s 2018 Global EV Outlook. Subsidies and tax credits aren’t included in our calculation.

Are electric vehicles greener?

“Green” can mean different things in different contexts. Our attempt to answer the question takes into account three types of environmental costs that can come from using cars.

1. Particulate pollution: These are small particles—typically less than the diameter of human hair—produced by gasoline-powered cars. They can enter the bloodstream through the lungs and cause damage to lungs, heart, and brain. Electric cars don’t have tailpipes, which means on this measure they are definitely greener.

2. Metal mining: The rarer the metal, the higher its environmental cost. Electric cars have fewer parts than the equivalent gasoline-powered car, which means they need less steel. But electric cars are often powered by lithium-ion batteries that use cobalt, which is mostly mined unsustainably in the Congo, one of the world’s poorest countries. On this front, electric cars aren’t greener yet. (We include the carbon-dioxide emissions of mining as part of the last measure.)

3. Carbon-dioxide emissions from energy source: Electric cars don’t rely on fossil fuels, but often some of the electricity they use ultimately comes from burning coal or natural gas. That said, even when electric cars do rely on fossil fuels, they are still much more efficient than internal-combustion-engine cars that burn gasoline. Only 25% of the energy generated by light-duty gasoline cars is used to actually move the car; electric vehicles powered by lithium-ion batteries  use 95% of the energy they generate to move.The upshot is that, even when the grid is powered only using coal, electric cars generate less carbon-dioxide emissions than gasoline-powered cars, making them definitely greener.

4. Lifetime carbon-dioxide emissions: This is the most comprehensive measure of a car’s carbon-dioxide emissions. It takes into account emissions from the energy source used to drive the car, as well as emissions released in the production and distribution of materials used to build the car. The lithium in lithium-ion batteries, for instance, needs to be shipped vast distances before it becomes part of the battery. Even after including these extra emissions, electric cars produce fewer greenhouse gases over their lifetimes compared to gasoline-powered cars, according to research done by Institute for Data, Systems, and Society at MIT.

Of course, the cleaner the electric grid, the cleaner the electric cars. In the interactive below, you can test out what that means. California, for example, draws on fossil fuels for 40% of its electricity, compared to the US as a whole, which clocks in at 60%.