An electric car has no tailpipe and the car itself doesn’t emit any pollutants directly into the air. But an electric car is not truly a zero emission vehicle because the electricity that fills its battery pack has to be generated somehow and this is often by burning coal.
Of course, if the electricity in an EV’s battery is produced directly by 100 percent renewable energy forms such as wind, solar and hydroelectric power, an electric car might in fact be accurately called a zero emission vehicle. Then again, maybe not.
Solar, Wind and Air Pollution
Renewable energy forms such as solar, wind and hydro do technically contribute to air pollution. Air pollution is produced when the raw materials needed to build renewable energy producing devices are harvested, when renewable energy devices such as solar modules are produced, and when they are transported to the place where they’re installed.
Once these renewable energy producing devices have achieved what’s called “energy payback”—the time it takes for them to produce as much energy as it took to produce them—they begin to create pollution-free electricity. And, if you plug an electric car into an electricity stream solely produced by devices that have achieved energy payback, you will in fact be driving a 100 percent zero-emission vehicle.
Of course, the scenario in which an electric car owner might end up driving around in an EV whose batteries have been charged 100 percent by renewable energy-producing devices that have achieved energy payback is a rare occurrence.
Pacific Northwest and Hydro Power
In the U.S., those who live in the Pacific Northwest, where a large percentage of electricity is generated by hydro power and who also have home solar, residential wind, residential geothermal electricity—or all three of these—are among those most likely to achieve true 100 percent air pollution-free electric driving.
Those who have home solar but who live in places like, for instance, Colorado—where I happen to live—are less likely than folks with solar in hydro-producing regions to achieve that “pure” zero emissions driving experience. This is especially true if the electric car gets plugged in at night, when there is no sun, and the EV owner is using solar to offset electricity generated during the day to power the vehicle.
In this case, most likely the EV will be fueled with a mixture of coal and natural gas generated electricity and, perhaps if you’re lucky, via a smattering of wind-generated electricity as well.
If you plug that same EV in during times when a home solar system is producing enough electricity to meet the EV’s full electric draw plus the rest of the household electricity use at that moment in time, you are indeed back to true zero emissions driving.
However, just one puff cloud that reduces your solar output enough to force your household to temporarily draw some electricity from the general electric grid, and poof. Just like the appearance of the cloud itself, your claim to true 100 percent zero emissions driving becomes a passing thing.
Putting Your Car Through a Greenwash
If 100 percent zero emissions driving is rare, why call it zero emissions in the first place? To me, zero emissions feels like an attempt at greenwashing, or an attempt to make people forget the often dirty energy sources used to generate the electricity EVs run on, even if only part of the time.
It’s difficult to believe such greenwashing works—especially given the volume of fervent anti-EV rhetoric out there that so often attacks the term “zero emission.” In fact, I believe “zero emission” backfires. In its attempt to obscure the original fuel source, the term ends up drawing extra attention to the fact that the electricity powering an EV’s batteries is usually generated by a mix of electricity.
Again, for most people, this mix is likely a mixture of coal, natural gas and nuclear with perhaps a smattering of renewable energy—though grid mix varies widely based on where you live in the U.S. (EV critics tend to ignore regional and local grid mix variability).
Gas Cars Have Long Tailpipes Too
It is important to point out that gasoline cars are also connected to the coal smokestack via the electricity intensive oil refining process—a key point that 99 percent of EV critics ignore.
However, the fact that gasoline cars also run partially on coal doesn’t erase the fact that virtually every EV out there will be running on electricity generated at least some of the time via coal and/or natural gas. This includes my own future solar-charged EV because I will sometimes be plugging in when our 5.59 kW home solar system isn’t producing enough electricity, meaning at night, when it’s cloudy, when snow covers our panels, etc.
On the other hand, the whole thing can be pushed to absurdity: For instance, if an EV can’t be called zero emission because it’s got a long tailpipe, does this mean we need to be talking about long tailpipes for refrigerators, computers, clothes dryers, and desk lamps.
Zero Tailpipe Emissions
In the end, I don’t feel comfortable with the term zero emission. It just doesn’t seem fully accurate. Where does this leave us then? What if we amend the term to this: Zero tailpipe emission vehicle?
Zero tailpipe emissions accurately captures the fact that an individual EV has no tailpipe and emits no pollutants directly into the air where it is being driven. And, no matter how you look at things, zero tailpipe emissions is a huge advantage. Just ask the millions of people sitting in a traffic jam somewhere in the world right now breathing in the fumes from the hundreds, even thousands, of vehicles around them.
What do you think? Is “zero emission” vehicle accurate, or do you prefer “zero tailpipe emissions?” Or maybe you have a better term for the EV community to consider.
With solar power well on its way to grid parity, and other renewables making progress as well, the same EVs which we buy today, will allow zero emissions in the future, to the same degree as electricity generation becomes cleaner. So EVs do much more than have zero emissions at the tailpipe (which however in itself is a great thing). I don't mind at all if that draws attention to the need for clean electricity, since that is something we want in any case. In fact, I see that as a positive.