You have no doubt read that “California is going to ban gas-powered cars”, starting a dozen years from now.
Which they actually are not, if you bother to read the details. But that’s for another post.
This announcement out of California has been followed by the usual internet crap-storm of misinformation, disinformation, and ignorant opinion.
Of course nobody bothers to look up the facts first.
Or, God forbid, do a little math.
Let’s start with the math. To answer the following question:
How many roads must a man drive down, before he crashes the grid?
If we magically converted all the passenger vehicles in the U.S. to electricity, today, roughly how much more electricity would we need to generate?
The answer requires just three bits of information.
- How many miles do we drive now?
- How much electricity do we generate now?
- How far can you travel on one one kilowatt-hour of electricity?
Source: Federal Highway Administration June 2022 Traffic Volume Trends report.
Point 1: Americans drive about 3 trillion miles per year. This is vehicle miles, so it includes everything from passenger cars to 18-wheelers. If you break it down further, you’ll find that 90 percent of that is light-duty vehicles, which corresponds roughly to passenger vehicles of all types, everything from cars to light (two-axle) trucks. (Calculated from this source: FHWA, Bureau of Transportation Statistics.) In round numbers, then, the U.S. passenger vehicle fleet travels 3 trillion miles per year.
Source: US Energy Information Administration.
Point 2: America produces about 4 trillion kilowatt-hours of electricity a year. (Plus a little rounding error for rooftop solar.) Note that the share of carbon-free and carbon-light generation (i.e., anything-but-coal) has mushroomed in the past decade. This is why the carbon footprint of electrical generation in the U.S. has shrunk so much. And that is why there’s the big push for electrical transportation.
In case you missed it, this started with the Obama-era Clean Power Plan. Which, of course, the subsequent Republican President undid. But at this point, market forces are the main driver behind this, with environmental concerns merely a nice fringe benefit. We’re going to get Obama’s clean grid whether we like it or not.
Source: Electrek.co.
Point 3: The average EV sold today gets about 3 miles per kilowatt-hour. That’s based on citations from several non-official sources (like this one), and appears to be a sales-weighted average.
Source: Fueleconomy.gov, 2022 model year, all cars that use electricity.
That average is interesting, given that the best of the best EVs have an EPA rating of 4 miles per KWH. (My wife’s Prius Prime gets that, per the EPA, but we get well over five driving around town). Even the godawful Hummer EV pictured above gets almost 2 miles per KWH.
This is, after all, America. When it comes to cars, nothing exceeds like excess. But compared to gas cars, the inherent efficiency of the electric platform seems to limit the amount of natural resources that you can squander hauling around tons of steel. It compresses the roughly 5-to-1 efficiency difference across various gas vehicles down to a far more modest 2-to-1 difference. Per the EPA, if you Hummer-size your EV, you only get to burn twice as much fuel as a Prius.
So nyah.
Do the math and have a little common sense.
If we instantaneously converted the entire US passenger vehicle fleet to EVs, we’d need another trillion kilowatt-hours of electricity, or roughly 25% more than we produce now.
That’s not rocket science. To travel our 3 trillion annual miles, at 3 miles per KWH, we’d need 1 trillion KWH. We make 4 trillion KWH now. So, we’d need to produce 25% more electricity.
Common sense part 1. We’re going to have decades to get that done, because electrification of the U.S. passenger fleet will proceed at a snail’s pace. The U.S. has about 250 million passenger vehicles (Source: FHWA, Bureau of Transportation Statistics, all light-duty vehicles). Each year, we buy around 17 million new vehicles per year (Source: Federal Reserve Bank of St. Louis FRED system).
Even if every new passenger vehicle sold in the U.S. was an EV, it would take the better part of a decade to replace the existing stock of 250 million vehicles with EVs. But back here in the real world, we just crossed point where 5% of current new-car sales are EVs. Based on the experience of other countries who have electrified their passenger fleets, that figure is expected to reach 25% in 2025. Beyond that, it’s hard to say what would happen next, because so few countries have exceeded that fraction. (Source for all that information is Bloomberg).
When you run all that through a grinder, you’d have to guess that we have at least three decades to add that new electrical generation, probably more. So we’d have to increase electrical generation by less than 1 percent per year, beyond the existing growth rate, to handle any remotely plausible increase in EV use in the U.S.A. That hardly strikes me as infeasible.
But wait, there’s more.
Probably the biggest joker in the deck here is night-time charging.
If we fully electrified all the existing passenger vehicle miles in the U.S., we’d need to produce 25% more electricity. But that’s doesn’t mean 25% more generation capacity. And that doesn’t mean 25% increase in the grid’s ability to delivery electricity.
How much new capacity we’d need would depend on the extent to which we can convince people to charge at night. And, secondarily, the extend to which our electricity is generated by solar-with-no-storage (which is off-line at night by definition.)
Focus on the July peaks (in yellow) in the diagram above. That’s how much electricity our existing system is capable of producing and delivering.
Any time we’re below those peaks, there’s spare capacity somewhere. (Ignoring the issue of solar as a fraction of all generation.) It may be relatively expensive to produce at those peaks, but it’s clearly feasible. We do it every year.
And, as you can plainly see, any time other than summer, U.S. electrical demand is well below those peaks. And in the summer, nighttime demand is well below those peaks.
The fact is, all we’d have to do is convince/require all/most EV users to charge at night, during the summer. (Ideally, to charge at night all the time). If that could be achieved, the additional electrical generating and delivery capacity would be minimal.
This isn’t a new idea. The benefits of charging EVs at night has been around about as long as modern EVs have been. It’s just that all the nay-sayers conveniently overlook it.
More to the point, all modern EVs come with the capability to schedule the charging time. You can plug it in at any time, but you can tell it to charge only in the middle of the night. So the opportunity for nighttime charging is a standard feature. All we need is the common sense to put in a system that either enforces or strongly incentivizes it.
But but but …
But won’t EVs use up all the fuel we need to make electricity? Comfort yourself with this thought: The U.S. has about a century’s worth of natural gas, as “technically recoverable reserves”, given the current use rate (Source: US EIA).
But won’t solar be so big a share of generation that nighttime charging is infeasible? I don’t think we’re going to have to sweat that. At present, solar accounts for about 0.1 trillion kilowatt-hours of electrical generation in the U.S. (Source: US EIA). Restated, solar accounts for about 2.5% of all the KWH produced in the U.S. This probably will be an issue in sun belt states with high installed solar capacity. It’s not really an issue for the U.S. as a whole.
Conclusion
Sure, parts of the grid may crash some time in the near future. Think Texas in wintertime.
But that ain’t going to be due to EVs. Not now, while EV charging is a drop in the bucket. Not in the next decade, for sure, ditto. And, if we have even the tiniest amount of common sense, not ever.
There are plenty of reasons to be skeptical of mass conversion to electrical transport. My greatest concern is that there’s no rational plan for disposing of all those big batteries. Yet. (The Feds had one at some point, but I haven’t seen anything about that in years. Maybe that’s quietly proceeding. Maybe that died with the Clean Power Plan.) Plus, we need consumer acceptance. And infrastructure for on-the-road charging. And charging opportunities for other-than-single-family-home dwellings. And, with the currently dominant battery chemistries, we’ll need metric craploads of exotic materials.
And so on.
Plenty of things to worry about. But crashing the grid isn’t one of them.
