The promise of alternative fuels is big: they could reduce our dependence on foreign oil, contribute to green technologies, and best of all, we could all continue to travel around as we always have—in our own personal cars—but without all the guilt associated with combustion engines and the fossil fuels they burn. Manufacturers and sellers of vehicles that run on alternative fuels—be it electric, hybrid, hydrogen fuel-cell—capitalize on assuaging consumer guilt, and our government has even begun offering incentives (in the form of tax rebates) to those willing to drive vehicles not powered by gas. But the impact of our activities on the earth–especially driving–is still not going to be zero, even if we drive vehicles deemed more responsible.
Electric cars seem to be edging out the alternative-fuel competition—high-end, high-performance Tesla continues to make waves, tech giant Apple promises to introduce an electric car in just three short years, and about 330,00 electric vehicles already drive on U.S. roads every day. But though electric vehicles (EVs) emit no pollution while driving, they must be charged at night with electricity generated by power plants. If the power plant is clean (powered by natural gas or hydrogen), the electricity remains fairly clean, but if it’s coal, charging an electric car can end up taxing the environment as much as—or in some cases, even more than—a gasoline-powered vehicle.
The Dirty Underbelly of Electric Vehicles
The National Bureau of Economic Research recently published a study in which researchers, “determined the emissions produced by gasoline car tailpipes and the emissions produced by electricity grids that power EVs for every U.S. county.” They then mapped the results to demonstrate “where gas cars and EVs cause more respective pollution.” More details about how researchers calculated “the environmental cost of driving” both a gas car and an EV, by U.S. county, can be found here.
Researchers used 11 2014 EV models and their closest gas-powered equivalents. City Lab laid out the findings: “For the gas car, the worst damage … tends to occur in highly populated urban areas. That makes sense, because that’s where tailpipe emissions can do the most immediate social harm.” And for the EVs: “In the West, where the power grid tends to be clean, electric vehicles did little damage. But in the Midwest and Northeast, where the electricity grid tends to rely on coal power plants, the damage from emissions [was much higher]. Texas and the South were in the middle of the pack.”
Because EVs actually cause more pollution per mile driven in some areas of the U.S., researchers argue that rather than EV owners receiving a government subsidy for their vehicles, they might actually need to be taxed in some places.
But the bottom line, says City Lab, is that all types of vehicles impact the environment—EVs and gas-powered alike. Researchers offer a solution many economists have long called for: “Charging a per-mile pollution fee based on both vehicle type and geography.” Charging drivers fees for pollution is, many economists say, an effective way to get people to reduce harmful behaviors.
The Rest of the Picture
While this study sheds light on an important aspect of alternative fuels, namely that they aren’t without environmental cost, only looking at fuel and electricity expenditures (as with the National Bureau of Economic Research study), doesn’t paint a complete picture. The study’s author acknowledge that their study doesn’t take “a full ‘lifecycle’ analysis of emissions—so things like making the car, drilling for oil, or transporting coal aren’t included in the environmental costs.”
As a counterpoint, take a study detailed by the MIT Technology Review: looking at the “cradle to the grave” life cycle of both EVs and gas powered vehicles, they say, “The study found that while the environmental impact of making electric vehicles is greater than for making gas and diesel vehicles, this is more than made up for by the greater impact of gas and diesel vehicles while they’re being used. This is true in terms of total energy consumption, use of resources, greenhouse gases, and ozone pollution. The electric vehicles were assumed to be charged from a grid that includes significant amounts of fossil fuels.”
Other Pollution Concerns
It’s also important to look at the type of pollution each fuel source produces. As the MIT Technology Review reminds us, greenhouse-gas emissions aren’t the only form of pollution we need to be concerned about: “acid rain, ozone pollution, algae blooms, consumption of water and materials such as steel and copper, and total energy demand,” are also important. Electric vehicles, they report, “come out behind in two areas. They contribute slightly more to acid rain. And they’re slightly worse in terms of causing algae blooms than gasoline cars (but better than diesel).” But in other areas, EVs come out ahead.
Oil, as we know, is a finite resource, the acquisition of which is becoming increasingly fraught (both at home and abroad). City Lab argues that while electric vehicles might not be zero-impact, they are at least moving in the right direction, and if the power grids charging them become greener, so will the vehicles themselves.