A recent Wall Street Journal story compares an electric vehicle (EV) with a similarly sized internal combustion engine (ICE) vehicle over their useful lives, and finds that “EVs produce fewer emissions overall than their gas-powered counterparts, but there are caveats.” It concedes that EVs start out in the hole, since manufacturing the battery requires more energy than for a conventional engine and thus emits nearly five more tons of related greenhouse gas (GHG) emissions. However, once out on the road, the average EV uses (presumably) lower-GHG electricity instead of gasoline, and pays off its carbon debt by about 20,600 miles. After that, the EV pulls ahead and by 200,000 miles (“the typical lifespan for a car,” according to the article) and has saved 42 tons of carbon dioxide emissions as compared to its ICE counterpart, not to mention an estimated $1,200 in overall ownership costs.
However, if EV batteries don’t last nearly that long, then the environmental and consumer calculations are very different. And there are reasons to believe they won’t.
An excellent article on EV battery life in the Telegraph answers the thorny question of battery life with a definite “it depends.” Theoretically, an EV battery can last for 200,000 miles, but only if it is well taken care of by an owner willing to make certain sacrifices.
For example, it is bad for battery life to regularly charge it all the way to capacity or to drain it below 20 percent before recharging. But keeping to this vigil cuts into vehicle range and requires more frequent charging, which are already issues for many EV owners.
It is also wise for the sake of battery longevity to not make a habit of using fast chargers—public charging stations that can provide a 30 minute or so jolt rather than a battery-friendlier but hours-long recharge at home. However, avoiding fast charging both adds to charging times and makes longer trips unfeasible, again exacerbating the shortcomings with EVs.
Battery life is also compromised by use in regions with very hot summers or very cold winters, especially if the vehicle is not kept in a climate-controlled garage. So EV enthusiasts in some parts of the country may have to accept somewhat shorter battery lifetimes.
The Telegraph notes that “the cumulative effect of having to renew battery-electric cars every 10 years compared with, say, every 15 years makes an enormous difference on their environmental impact.” Indeed, if a second battery is needed to keep an EV on the road as long as an ICE vehicle, that means a second round of manufacturing-related GHG emissions, not to mention double the mined materials (cobalt, lithium, rare earths, graphite, nickel, copper, and others) to make the replacement battery. It also means up to $16,000 in consumer costs for a replacement battery, assuming the EV warranty has expired. This is more than enough to tip the cost balance clearly in favor of an ICE vehicle. And even if there is a relative savings in greenhouse gas emissions, the cost per ton avoided may make EVs one of the costliest climate policy options on the table.