By the end of the decade, battery-electric vehicles could make up as much as 30% of the U.S. new vehicle market, proponents billing the technology as a major step toward reducing carbon dioxide and other harmful emissions blamed for global warming.
But do EVs really live up to that billing? What’s clear is they have unique requirements for materials used in their batteries, as well as metals, such as aluminum, needed to reduce weight and improve range and performance. And that actually increases the energy footprint of an EV compared to a conventional vehicle from the manufacturing point of view.
Long term, EVs are cleaner, though you’ll have to drive one an average 13,500 miles to get into the green, if you will, from an environmental standpoint. That’s based on an extensive study of lifetime vehicle emissions conducted by the Reuters news service using data from the Argonne National Laboratory in Chicago.
Factoring in the variables
There are a lot of variables that go into the equation, including the size of both the vehicle and its batteries. The larger — and, thus, the longer range — the pack the more materials like cobalt and nickel are needed, Jarod Cory Kelly, the principal energy systems analyst at Argonne told Reuters.
But other factors influence the “breakeven point” where EVs begin contributing positively to the environment. Among other things, it can depend upon what source of energy is used, both in the manufacturing process and to charge up a battery-electric vehicle once it is on the road.
Reuters compared a Tesla Model 3 with a relatively small, 54 kilowatt-hour battery against a Toyota Corolla with a fuel economy rating of 33 mpg, and it estimated that both vehicles would clock 173,151 miles during their time on the road.
That scenario also focused on the two vehicles being operated in the U.S. where 23% of the nation’s energy comes from coal-fired plants. In that case, the Tesla would only become cleaner — making up for the higher emissions during manufacturing — after driving 13,500 miles. That’s roughly equivalent to what the typical American motorists clocks in a year, generally considered to be between 12,000 and 15,000 miles. So, each year after that, the EV would be contributing positively to the environment.
“Breakeven” comes quickly where renewables are used
In markets where coal is not used, and especially in countries heavily reliant on renewables, the breakeven point comes more quickly. Using the Argonne data, Reuters concluded the Tesla would have an environmental payoff much more quickly. In Norway, which relies primarily on electricity for its power, that would come after just 8,400 miles.
In countries primarily dependent upon coal-fired generators, the payoff is still there, though it comes much later. In China and Poland, both almost exclusively dependent upon coal, breakeven would take 78,700 miles.
The Reuters report is based on a “wells-to-wheels” study which looks at the amount of energy required from the point where raw materials are mined until the vehicle reaches the end of its life. Most research focuses on just the advantages of operating an electric vehicle once it drives out of the showroom.
Once driven home, EVs gain the edge
It’s in the process of manufacturing that battery-powered cars have a distinct disadvantage.
“The Reuters analysis showed that the production of a mid-sized EV (sedan) generates 47 grams of carbon dioxide per mile during the extraction and production process, or more than 8.1 million grams before it reaches the first customer,” the news service reported. “By comparison, a similar gasoline vehicle generates 32 grams per mile, or more than 5.5 million grams.”
Once driven home, however, EVs quickly begin gaining the edge. That’s particularly true where renewables provide power for charging. But even if the local utility relies on coal, EVs eventually fall on the environmentally friendly side of the ledger, based on the Argonne data.
