Comparing Energy Costs per Mile for Electric and Gasoline Vehicles

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1. John Michael Greer on the electric car

For those Americans who actually do find themselves in need of a car, how about the new electric vehicles? Will they really decrease your carbon footprint and your fossil fuel use, as so much current verbiage claims?

The answer is unfortunately no. First of all, as already mentioned, the vast majority of electricity in America and elsewhere comes from coal and natural gas, and so choosing an electric car simply means that the carbon dioxide you generate comes out of a smokestack at a power plant rather than the tailpipe of your car. The internal combustion engine is an inefficient way of turning fuel into motion – around 3/4 of the energy in a gallon of gas becomes low-grade heat dumped into the atmosphere via the radiator, leaving only a quarter to keep you rolling down the road – but the processes of turning fossil fuel into heat and heat into electricity, storing the electricity in a battery and extracting it again, and then turning the electricity into motion is less efficient still, so you’re getting less of the original fossil fuel energy turned into distance traveled than you would in an ordinary car. This means that you’d be burning more fossil fuel to power your car even if the power plant was burning petroleum, and since it isn’t – and coal and natural gas contain much less energy per unit of volume than petroleum distillates do – you’re burning quite a bit more fossil fuel, and dumping quite a bit more carbon in the atmosphere, than a petroleum-powered car would do.

This isn’t something you’ll see discussed very often in e-car websites and sales flyers. It’s even less likely that you’ll find any mention there of the second factor that needs to be discussed, which is the energy cost of manufacture. An automobile, petroleum-powered or electric, is a very complicated piece of hardware, and every part of it comes into being through a process of manufacture that starts at an assortment of mines, oil wells, and the like, and proceeds through refineries, factories, warehouses, and assembly plants, linked together by long supply chains via train, truck or ship. All this costs energy. Working out the exact energy cost per car would be a huge project, since it would involve tracking the energy used to produce and distribute every last screw, drop of solvent, etc., but it’s probably safe to say that a large fraction of the total energy used in a car’s lifespan is used up before the car reaches the dealer. Electric cars are as subject to this rule as petroleum-powered ones.

The energy cost of manufacture has generally been downplayed in discussions of energy issues, where it hasn’t been banished altogether to whichever corner of the outer darkness it is that provides a home for unwanted facts. (I’ve long suspected that this is not too far from “Away,” the place where pollution goes in the parallel universe that cornucopians apparently inhabit.) Promoters of the more grandiose end of alternative-energy projects – the solar power satellites and Nevada-sized algae farms that crop up so regularly when people are trying to ignore the reality of ecological limits – are particularly prone to brush aside the energy cost of manufacture with high-grade handwaving, but the same sort of evasion pervades nearly all thinking about energy these days. I’ve mentioned before that three centuries of cheap abundant fossil fuel energy have imposed lasting distortions on the modern mind; this is an example.

Still, factor in the energy cost of manufacture, and there actually is an answer to the question we’ve just been considering. If you really feel you have to have a car, what kind involves the smallest carbon footprint and the least overall energy use? A used one.

I suppose it’s just possible that one or two of the readers of this blog will remember a strange and politically edgy comic strip from the Sixties named Odd Bodkins. The rest of you will just have to forgive a bit of relevant reminiscence here. Somewhere between an encounter with the dreaded Were-Chicken of Petaluma and a journey to Mars with Five Dollar Bill, I think it was, the Norton-riding main character, Hugh, and his sidekick Fred the Bird had a run-in with General Injuns – the resemblance to the name of a certain large American automotive corporation was not accidental. I forget what it was that inspired Fred the Bird to shout “Buy a used car!” but the General’s response – “BLASPHEMY!!!” – was memorably rendered, and will probably be duplicated in a good many of the responses to this week’s blog. Most people in the industrial world nowadays are so used to thinking of the best option as new and shiny by definition, that the homely option of picking up a cheap used car as a way of saving energy is likely to offend them at a cellular level.

Still, the energy cost of manufacture needs to be taken into account. If you buy a used car – let’s say, for the sake of argument, a ten-year-old compact with decent gas mileage – instead of a new electric car, you’ve just salvaged the energy cost of manufacture that went into the used car, most of which would otherwise have been wasted, and saved all the energy that would have been spent to produce, ship, and assemble every part of the new car. Since it’s a ten-year-old compact rather than a brand new e-car, furthermore, you’re not going to be tempted to drive it all over the place to show everyone how ecologically conscious you are; in fact, you may just be embarrassed enough to leave it in your driveway when you don’t actually need it, thus saving another good-sized chunk of energy. Finally, of course, the price difference between a brand new Nissan Leaf and a ten-year-old compact will buy you a solar water heating system, installation included, with enough left over to completely weatherize an average American home. It’s a win-win situation for everything but your ego.