One of the key components of the plan to get our civilization to net zero by 2050 is to transform the motor vehicle fleet into all electric vehicles (EVs). This is a worthy goal, as it would eliminate burning gasoline for transportation. In fact it’s necessary if we want to get near net zero. Governments and the auto industry are responding with incentives for EVs, some regulations forcing the phasing out of internal combustion engine (ICE) vehicles, and investment of billions even trillions of dollars to change over production lines, secure raw material sources, and build charging stations.

But EVs have their critics. And some experts point out (a valid point I completely agree with) that we have to consider the optimal pathway to net zero, not just the destination. By 2050 EVs will be an even more mature technology than they are now, and batteries will have at least 4-5 times the energy density. We may also have battery designs that use more abundant and less problematic raw material.  Also by then there should be a robust infrastructure of charging stations, and a green energy grid to support them. So it’ easy to imagine the world of 2050 with an all EV transportation infrastructure that is as close to net zero as possible.

I also have to say, I own a Tesla and it’s the best car I ever owned. The driving experience is great – once you get used to the regenerative breaking, you have more and easier control. Acceleration is instantaneous. Charging at home every night is easy, and you never have to visit a gas station. There is literally almost no maintenance – no oil changes, no tune-ups, no engine parts that wear out. The break pads last much longer because you very rarely use the breaks. At least along the East coast, long trips are no problem.

But what is the optimal path to get to full EV? And this is not just about getting there quickly. EVs may not be the best option for everyone right now. The optimal path may go through bridging technologies, most notably plug-in hybrids. What are the downsides to EVs?

Here is an article I was recently sent from the Daily Mail – not what I consider a reliable source of unbiased information, and the article is very slanted, but the basic facts are essentially correct. The bias is in what they emphasize and what they leave out. The main point is that EVs are more expensive and carbon-intensive to build, so they are not as green as people may think. This is old news, however. They ironically include the fact, without pointing out the true relevance, that on average you have to drive 50,000 miles in order to pay back through reduced emissions the carbon deficit incurred through manufacturing. This will depend on the vehicle and the energy mix where you charge your vehicle, but this is using average figures. (I have solar panels, so my energy mix is much better than average.)

What they don’t mention is that the average lifespan of a car on the road today is 200,000 miles, and that EVs (because of the whole low maintenance thing) are projected to last 300,000 miles on average.  Even if we use the lower figure, that’s 150,000 miles of emissions-free driving after you have paid off the carbon deficit. If we use the 300,000 mile figure, it goes up to 250,000 miles of carbon-free driving. And then you have to include the lower overall manufacturing cost from a longer-lived car. And you have to include the effect of lower maintenance. If you do a lifetime analysis, EVs are much superior to equivalent ICE vehicles. It’s no contest.

And that is with current technology and current energy mix. This comparison will only get better for EVs as battery technology inevitably improves, and our energy mix gets more green. Improvements in battery technology is not wishful thinking – regular readers know I like to follow battery news. There is already in production (for now for aviation) a silicon anode LiIon battery with twice the energy density as existing batteries, with the potential to double again by the 2030s. This is already baked into the pipeline. Add 20 years to that progress and think about where we will be by 2050.

But there are some legitimate issues we need to confront. The LiIon battery technology is great, but each battery uses a large amount of lithium, nickel, magnesium, and cobalt. Ramping up battery production for EVs is stretching supply lines thin, and there is legitimate concern that this will become a bottle neck for production. Further, China has monopolized these supply lines in recent years, and they seem set to continue to do so, securing a new source of lithium in Afghanistan. Western countries are scrambling to add new sources of their own, but for the next decade this is going to be a serious issue. There are some wild cards here – companies are exploring purifying lithium and other minerals from ocean water (an effectively limitless supply), and there are polymetallic nodules on the ocean floor with everything we need to make batteries. But there are still environmental concerns and cost-effectiveness to consider. These are not established supply lines.

Newer battery designs may swap in iron and phosphorous, which are cheaper and more abundant, and there are other battery designs in the pipeline. But again, any new solution like that is for next decade. This essentially means that we are a full car lifetime away from any of these game-changing solutions. The cars people buy now they will be driving for the next 12 years on average. This gets back to the pathway consideration.

I think there are two important points to make here, both covered in this thoughtful article in the Washington Post. There are two potential problems conceptually with our current approach to EVs – purity and range anxiety. By “purity” I mean feeling the need to go 100% electric with zero fossil fuels. While again, this should be the goal, we need to consider what gives us the most bang for the buck in the short term. This also relates in an interesting way to range anxiety, fear of running out of electrons far from a recharging station, or having trips interrupted by long recharge times.

Americans, as least, are obsessed with longer range EVs. I admit to this bias myself. It just feels better to know that fully charged my car can go 350 miles, and this definitely does make longer trips easier. But let’s put this into perspetive.

Most people drive less than 30 miles on a given day, and 90% of trips are 31 miles or less. Averages don’t always tell the whole story, and this will not be true for everyone everywhere. But for most people, daily car use requires very little range. If you own your own driveway, and essentially have a place to recharge over night, a car with a very short range is perfectly adequate most of the time. For EVs this means that a car even with a 150 mile range is more than enough for 95 plus percent of the time. Most people take very few trips throughout the year longer than this.

For full EVs it makes no sense to carry around a heavy large battery with a 350+ mile range (let alone 400-500 miles as some new cars have) just for the rare long trip. That is a lot of battery raw material that could be used to make more EVs. Also, EVs are heavy, which makes them less energy efficient. Smaller batteries are lighter, which increases the range you get out of a fixed amount of battery, so they are more efficient.

So it’s pretty clear that there are numerous advantages to designing EVs with smaller batteries, and that the solution to range anxiety should not be wastefully larger and larger batteries. The solution is building more recharging stations. This may mean more stops on longer trips, but the trade-off is a cheaper car, and more efficient car, a lighter and possibly safer car, less wear and tear on the roads, greater carbon efficiency, and a drastic reduction on the raw material supply line.

The other possible solution is plug-in hybrids. A typical plug-in hybrid, for example, may have a range off just the battery of 44 miles. Again, this covers more than 90% of trips. So if you can recharge every night, most of your driving is electric. For longer trips, you have a small and efficient gas motor to extend the range of the battery. There are a lot of technical options within the plug-in hybrid design – does the motor drive the car also, or just recharge the battery, for example. Either way, this will drastically reduce the burning of fossil fuels with a battery much smaller than a vehicle with a long range. If we think in terms of – how much CO2 production can we reduce per unit of lithium – plug in hybrids, and even regular hybrids, are a far better option than full EVs.

We may, therefore, need to set aside our purist desire for zero emissions now, or comforting our range anxiety with needlessly massive batteries. The “Moneyball” approach here (getting the most bang for the buck) means being frugal with our battery production. This means for many people a plug-in hybrid may be the best option. For others, a full EV with a range of 250 miles will do the trick. Increasingly fewer people will need ranges longer than that. Beyond a 250 mile range (again, for most people) you are basically treating your anxiety.

For long-haul trucks and large vehicles, eventually hydrogen may be the best option. Hauling around massive batteries, for now, is not a good option.

And technology will improve all of this. EV manufacturers are designing lighter vehicles. This gives us the rocket equation in reverse – a lighter vehicle means a smaller battery, which itself cuts weight and improves range, which allows for a still smaller battery, etc. An improved energy density in battery technology has the same rocket-equation benefit – they not only have a higher energy density, they become more and more efficient because they are lighter at a given range.

All of this also points to the need to build out our infrastructure of charging stations. There needs to be a string of charging stations along every highway. They need to be as ubiquitous as gas stations, perhaps more so. This is a good investment, and will reduce range anxiety and therefore the unsustainable drive for larger and larger batteries. Finally, the auto industry should not abandon plug-in hybrids too quickly. For the next decade this may still be a very useful car design. They should be optimized – perhaps make the batteries a bit more powerful, for example. For everyday use they should feel like driving an EV.

Remember, limiting peak warming is not just about getting to net zero, its about getting there through a pathway that releases the least amount of CO2.