Friday, October 5, 2012

Why not electrics?

c. 1900 Roberts Electric, one of the oldest known operating electric cars
BoingBoing science editor Maggie Koerth-Baker writes in The New York Times,
It will come as no surprise to hear that only a tiny fraction — less than 1 percent — of cars driving along American roads are fully electric. What might be more surprising is the fact that this wasn’t always the case. In 1900, 34 percent of cars in New York, Boston and Chicago were powered by electric motors. Nearly half had steam engines. What happened? Why do we end up embracing one technology while another, better one struggles or fails?
Her thesis is that, "Society shapes the development and use of technology," and we don't necessarily end up with the technology best suited for our needs (ie, VHS vs. Betamax). She doesn't really answer the electric car question, but says,
We drive gas-powered cars today for a complex set of reasons, Kirsch says, but not because the internal-combustion engine is inherently better than the electric motor and battery.
At the turn of the 20th century, the Electric Vehicle Company was the largest carmaker in the United States. It was also the biggest owner of cars in the country. That’s because the E.V.C. opted to rent or lease its vehicles instead of selling them. You could pick up an E.V.C. car for a short trip or take it for a week or a month, but you couldn’t own it. The business model was based on the E.V.C.’s assumption that its customers didn’t have the know-how or facilities to maintain their own cars. This may have been true, but when a series of shady business dealings drove the New York-based company into bankruptcy, it took electric cars down with it. Investors, soured by their experience with the E.V.C., swore they’d never put money into the industry again, and in the lull in electric-car development that followed, gasoline-car companies improved their technology and made their vehicles cheaper. Over the next 20 years, Americans formed a new idea of what a car was. And from that point on, right up to today, it was hard to get them to try anything else.
I agree that gas engines didn't win out "because the internal-combustion engine is inherently better than the electric motor and battery." But I would say that's almost the answer, and it's far simpler than a socioeconomic answer: Gas itself is better than electricity. We are still trying to equal the energy density of gasoline with a battery. Think about how much room a gallon of gas takes up; how much it weighs; and how much energy it contains (a whole heck of a lot). How much energy can 6.2 pounds of battery contain? A whole heck of a lot less.

Even today, gas other numerous benefits. Electric powered vehicles are operating at about 50% efficiency; while gas engines are barely 30%. But the curve of improvement for gas is much steeper than electric, meaning the energy density problem will become worse, rather than better.

Going back 110 years, then, you can see why it was a race. Electric cars had a much greater efficiency advantage, but it wasn't enough to overcome the energy density advantage of gas, and as gas engine efficiency improved, the electrics had nowhere to go. They were already as efficient as the technology of the era allowed, and the gas engine's return on energy investment curve soon surpassed the electric's. We may not have ended up with the technology best suited to our needs, but it was the one best suited to our capabilities.

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