We have a problem.
Collectively, we need to dramatically reduce our carbon emissions over the next few years to stave off the worst climate change outcomes. While this demands sweeping changes to energy policy at national and international levels, for individuals and organizations, electrification of the world’s automotive fleets offers the most direct change.
Electric vehicles are not perfect. They need metals, lots of metals. We are now pursuing increasingly complex ways to access those metals. Those metals include cobalt, copper, and nickel. These metals are critical components of the current generation of electric vehicle batteries. You find them on land, beneath Indonesia’s rainforests and in the Democratic Republic of the Congo and from within the Russian Federation, but you can also find them at the bottom of the ocean, locked up in polymetallic nodules scattered across the abyssal plain.
For more than 15 years I’ve been studying the environmental impacts of deep-sea mining, an industry entangled in the renewable energy revolution. There’s no good way to get metals out of the ground, but there are least bad ways and deep-sea mining may prove to be the least bad, but that answer isn’t clear, yet.
What is clear to me is that there is a third pathway. We don’t need to need these metals in the volumes projected by the most optimistic deep-sea mining proponents. We can reduce battery demands by changing how we commute, but we can also dramatically reduce metal demands while also substantially decreasing emissions from passenger vehicles by embracing what is perhaps the most important lesson for the modern environmental movement–don’t let the perfect be the enemy of the good–and considering an alternative EV that offers nearly all the the benefits of a full battery electric vehicle but with a significantly reduced load on critical mineral demands: the plucky, humble Plug-in Hybrid Electric Vehicle.
A plug-in hybrid electric vehicle (PHEV) is a car or truck with both a gas engine and an electric motor backed by a battery, but with a much larger battery than a conventional hybrid. PHEVs differ from traditional hybrids in that they can be charged directly from a power supply, rather than charging the battery exclusively from the engine and regenerative braking. Functionally, this means that a PHEV is an electric vehicle for short to medium length trips and an efficient hybrid for longer journeys. You can fuel it at gas stations or charge at charging stations, depending on what’s available.
The average daily commute in America is 24 miles. Almost all PHEVs currently on the market exceed this range (some by quite a lot) for electric driving, meaning that, when charged every night, a PHEV will spend most of its driving life as an electric vehicle. And when you need something to go farther, you have a vehicle that can make the long hauls, too.
PHEV critics will complain that these cars are transitional technology and if you can get an all-electric vehicle, you should. PHEVs are wasteful because you’re hauling around an engine that you don’t need most of the time and adding a bunch of extra maintenance costs.
Of course they’re a transitional vehicle. We’re in a transitional moment. Not everywhere has the infrastructure to support full electric vehicles, and we don’t yet have an electric vehicle for every use case. In a moment where many EV drivers continue to maintain a secondary gas car for longer trips, having one vehicle that does both is an opportunity.
Here’s the thing: I’m a critical minerals guy. If I’m driving the average American commute, I would much rather be hauling 200-pounds of extra aluminum in the form of a small inline 4-cylinder engine than hauling an extra ton of lithium, cobalt, nickel, and copper in the form of a high capacity battery.
I have a 2022 Ford Escape PHEV. The battery in it is 14.4 kWh and usually gets me about 38 miles of range (more when it’s warm out, less when it’s cold). I spend about 85% of my driving time in all-electric mode. A base 2022 Tesla Model 3 has a 50 kWh battery, with 272 miles of range (allegedly). For the battery capacity of a single base Model 3, we could have three and a half Ford Escape PHEVs on the road.
One of the major reasons people give for not going electric is that they don’t have the charging infrastructure to justify it and would still need a gas vehicle for long trips. This is a real concern. I live in a charging dead zone. I live in a rural community. I work in rural communities. There aren’t abundant chargers, even for Teslas, nearby. And that plays out in practice. The NOAA lab two towns over has a Tesla and a pick-up truck as their fleet vehicles. On many work trips where a hybrid would be perfectly adequate, they have to take the truck, because there just aren’t enough safe, reliable charging options. And they’ve tried, and been stranded. The truck is driven more, now, than it was before they had the Tesla.
PHEVs aren’t perfect, but they really seem to excel in rural settings, where most people have charging available at home but there is limited electric charging infrastructure on the road. Having an engine and an electric powertrain means you have two systems to maintain, but that doesn’t really present a significant challenge. My Escape, at least, has a simple Atkinson cycle engine, which is simple, reliable, and inexpensive to maintain. I get an oil change once a year. The way I drive, by the time I reach 100,000 miles on the car, there will only be about 15,000 miles on the engine.
On simple math, replacing 3.5 gas vehicles with PHEVs that are electric 85% of the time is a greater net positive than replacing 1 gas vehicle with 1 full electric vehicle. Even in the scenario when the owner isn’t charging regularly, 2 PHEVs running on electric 50% of the time is worth 1 full electric vehicle, using less than half the critical battery minerals.
That isn’t the entire story. Tesla, at least, is also software locking electric vehicle batteries, charging owners $2000 (or more) to unlock the extra range, to the tune of 60 to 80 extra miles. On that base model Tesla, there is an entire additional PHEV worth of critical minerals locked behind a paywall.
(Note: Tesla has recently begun transitioning some trim levels and some models to Lithium Iron Phosphate batteries, which are cobalt- and nickel-free, and that rocks).
For someone working in critical minerals, who is trying to find the balance between new mining ventures and responsible resource use, to bury that much material into a vehicle that can’t use it is unconscionable. It is a crime against our collective future.
The Experience
You can stop reading here, but if you’re interested in a personal account of owning a PHEV for the last 2 years, read on.
I’m a drive-it-into-the-ground car owner. With few exceptions, the most environmentally responsible choice is to maintain the car you have and then get the most efficient used vehicle you can once it goes. I kept an old Dodge truck running for 15 years, through high school, college, grad school, two post-docs, and two cross-country moves, putting enough miles on it to reach the Moon, and doing most of the major repairs myself. It could have made another moonshot if a rental trailer hadn’t failed, sending it hurling sideways down the highway at 65 miles per hour. That little truck was a tank.
When the replacement vehicle blew a head gasket in 2022 and turned the engine into sludge, I was in a bind. I knew our next car would be an electric or plug-in hybrid, but the spring of 2022 was one of the worst moments to buy a car in recent history, the used market was upside down, and dealers were trying to get new cars off their lots. Plug-in hybrids weren’t selling great near me and anyone who wanted them wanted the new Toyota RAV4 Prime. I somehow managed to get a decent deal on a new Ford Escape PHEV.
It was a good choice.
What is it actually like driving a plug-in electric hybrid in rural America? I live a few miles outside of a small town on the Maryland Eastern Shore. To get anywhere involves mixed driving; backroads, country roads, rural highways, and interstates. The nearest large town is 12 miles away and my university office is 30 miles away. I had a level 2 charger installed at my house, which can charge the car in about 2 hours. Since I work from home most days, in an average week I drive about 250 miles, with another 100 or 200 on the weekend, depending on if I need to go to Baltimore or DC. Sometimes I turn my car into a mobile sawmill.
The PHEV is rated for 37 miles of range. During the summer I averaged close to 42 and in the winter it drops to about 31 (EVs still aren’t great in the cold). My office has free charging, so practically, this means that during the week, the car is nearly always 100% electric. With electricity at $0.11 a kilowatt, functionally, this means that compared to my old SUV (which was only marginally larger than the Ford Escape), the first two gallons of gas that I would have burned each day now cost a little more than a dollar in electricity.
Highways do knock the range down a lot, but the car really shines on backroads, where the regenerative brakes earn their keep. Running my daughter out to her backcountry camp this summer, I could get almost 45 miles of range, thanks to the windy, hilly roads.
Since range anxiety doesn’t exist in a PHEV, I regularly push all-electric mode as close to zero as I can, without any worry that I might get stranded.
After almost 30,000 miles, the car is averaging 112 miles per gallon (that’s not adjusting for anything or doing any weird, black box math on mpg-equivalence; it’s just miles driven over gallons burned) and I regularly go more than 1200 miles between fill ups. Obviously, that can vary wildly depending on how much hybrid versus all electric driving I can manage in a week, but with a fully depleted battery in hybrid mode, I still average about 52 miles per gallon.