Coal-powered EVs? No. Yes. I mean, technically EVs could be a little coal-powered, depending on where you live and plug-in. And that’s OK.
The Nitty Gritty Details of EV Energy Sources
There is some truthiness to the common critique that EVs are “dirty.” Let’s face it—anything that is manufactured is a bit dirty. But it is also a big fat lie that EVs are dirtier than their internal combustion engine (ICE) counterparts (ahem, ICE-mobiles). And by dirty, I am mainly talking in terms of carbon footprints.
There are two recurring themes that usually crop up about EVs being dirty. The first is that the battery manufacturing process has a big carbon footprint, and it therefore follows that ICE-mobiles have a smaller carbon footprint. This is true-ish. Specifically, it’s only true at the time of sale, assuming that the cars in question are similar (i.e. not comparing an ICE Ford F350 dually to a smart EV two-seater city car). Cars are meant to be driven, and this is where the EV (taken over its lifetime) becomes “cleaner” than its ICE counterpart.
The second of the two recurring themes is that EVs are coal-powered. This is also true-ish, but only in those regions of the country that use coal to generate electricity. However, even when accounted for using coal to power the grid, the carbon footprint of an EV is still smaller than an ICE-mobile.
Nothing is ever so simple that it can be really understood in a few sentences. So to comprehend both of my previous claims, let’s dive into the heart of the matter.
Li-Ion Battery Carbon Footprint
Take the drive train out of the equation, and there is no reason an EV would have a larger carbon footprint than an ICE-mobile. A car body is a car body. Tires are tires, yada, yada, yada. Even the internal combustion engine itself doesn’t leave much more of a carbon footprint than the electric motor of an EV. Where the carbon footprint of the EV really comes into play is in its battery.
It’s no secret that lithium-ion (or Li-Ion) batteries are energy-intensive to make. The carbon footprint of an Li-Ion battery varies greatly, depending on everything from the lithium extraction process to the energy source used in the manufacturing process (i.e. if the battery was processed using electricity from coal or wind and solar).
Lithium is an element that can be extracted from hard-rock mining or brine reservoirs, the former being more CO2 intensive due to the heavy machinery involved. Once it is all rolled-up, the range of the CO2 generated during the manufacture of an 80 kWh battery can be from between 2,400 kg to 16,000 kg, according to a study performed by MIT.
That’s a lot of CO2, but it is also a large range. How does that compare to the CO2 emitted by an ICE-mobile? According to the same MIT study, 2,500 miles of driving for a “typical” gasoline-powered car generates about 1,000 kg of CO2 (assuming the car is getting about 22 miles/gallon).
If my calculator is to be trusted, that means it takes between 6,000 and 40,000 miles of driving that typical car to offset the manufacture of an 80 kWh battery, which is the typical size for modern EVs. That calculation only accounts for the CO2 generated during the combustion of the gasoline used while driving. If we want to look at the entire lifecycle, crude oil is energy-intensive to refine, bringing the number of miles needed to offset the production of an 80 kWh battery down to about 5,000 to 35,000 miles.
This is confirmed by the often-quoted metric used by EV advocates that, while the manufacture of EVs is more carbon intensive than an ICE-mobile, the field is leveled after driving the EV for about a year.
Are EVs Coal-Powered?
On the one hand, this cliche is so unimaginative that dignifying it with a response is irresponsible. On the other hand, this is a column for new EV owners to learn about their cars, so here we go.
Most homeowners don’t know what kind of electrons are pulsing in the wires throughout their homes. Are they nuclear-powered electrons? Wind? Solar? Hydro? Coal? By the time those electrons get to your home, there really is no way to tell because, at the subatomic level, all electrons are the same.
The good news is that there are many online resources to give any EV owner the historical, current and forecasted energy sources by nation, state, or region. It’s enough to give a data junkie endless hours of introverted clicking pleasure. For the rest of you, I’ve done the clicking on your behalf.
In 2021, which was the most recent year this data was available, coal represented about 22% of the power generated for the US electrical grid. Natural gas represented 38%. The remaining 40% was generated by carbon-neutral technology (wind, solar, hydro, and nuclear representing most sources).
On average, that means anyone accusing you of driving a coal-powered car is 22% correct. On any letter grade scale, that’s a solid F. Broaden that cliche to any carbon-generating source, and they are 60% correct, for a solid C-.
However, that represents the US average. Some regions do far better, and of course, others are far worse. Even if your EV is “mostly coal-powered,” take heart as the dirtiest EV is still cleaner than the greenest ICE-mobile. Stick a pin in that as we will get back to it.
If energy sources are a real concern for you, there are two options. The first is to see if your utility company has a “green energy” rate available. Not all utilities offer this, but those that do will (for about one penny per kilo-Watt hour more) source carbon-neutral energy for your electricity.
The other option is to generate solar power on your roof, should you actually own a roof to put it on. The return on investment typically takes around a decade or so, but solar is an economical option to ensure your EV is fission-powered if you take the long-term view. As Forrest Gump would say, EVs and solar go together like peas and carrots.
Anything Else I Should Know?
Not all Li-Ion battery chemistries are the same. Chemistries that use cobalt get a lot of bad press because much of the world’s cobalt is mined irresponsibly. The good news (and that’s my editorial comment) is that cobalt is expensive and makes for chemistries prone to thermal runaway when exposed to air and water. That’s a fancy way of saying they can spontaneously burst into flame. This is a big reason why companies are pushing research to minimize or eliminate cobalt in Li-Ion batteries.
Some EV manufacturers use lithium-iron-phosphate chemistry that is cobalt-free. This makes batteries that aren’t as energy dense but cheaper to manufacture and far safer if the individual cells are somehow compromised (e.g. in a collision).
Bringing It All Together
The cradle-to-grave carbon footprint of an EV vis-a-vis an ICE-mobile is much larger than the carbon footprint of the EV’s battery or the gas the ICE-mobile will burn throughout its life. Luckily for us, many reputable institutions and organizations have studied this and have come to the same conclusion—the dirtiest EV is still better than the greenest ICE-mobile. Even though many institutions have studied the concept, my favorite report is from the Union of Concerned Scientists. That might be because it is actually the only such report I’ve read from cover to cover, but it also might be because they developed this tool, which allows you to compare the carbon footprint per mile of any EV using the energy mix in your zip code.
What’s the One Takeaway I Should Remember Tomorrow?
When I talk to skeptics, I have found that being armed with the facts is rarely sufficient to change minds made up months ago by reading a meme on social media. Those biases are firmly held.
In these cases, I merely smile and say, “EVs are all about torque. Being green is merely a happy coincidence.”
Next week, we will discuss whether or not the EV boom means the world will run out of Lithium.