Measured Against Reality

Wednesday, November 29, 2006

Tesla Motors

Have you ever heard of Tesla Motors? I hadn’t either, until today, when I heard one of their engineers speak. They’re making an electric car. That might not sound like a big deal, but it is.

Their car, named Dark Star is a 250 horsepower, 0-60 in 4 seconds, 130 miles per hour top-speed sports car. It also gets an equivalent of 135 miles per gallon. If you’re at all like me, by now you’re thinking that it’s too good to be true.

The killer of most electric cars has been range. Dark Star’s range is a respectable 250 miles, which is more than enough to do your daily driving but not enough for a road trip. The other big flaw has been battery life, but Dark Star’s batteries last for 100,000 miles, double any previous electric car. And charging only takes three hours, easily accomplished over the course of a night.

The reason for the drastic improvements over previous electric cars is mainly due to the use of lithium-ion batteries. Tesla Motors uses the same batteries that are in your laptop, just 6,831 of them. This has tons of advantages, including easier heat dispersal, less weight, more charge density, and prolonged lifespan. Plus they don’t have to worry about battery technology: DELL, Apple, and all the other large companies that use them are already pushing performance up and costs down. Tesla Motors just has to ride in their wake.

The performance comes from the nature of electric motors. They have 100% torque efficiency at 0 rpm, and gradually decline. This car can go 70 mph in first gear, and only has two. And an 80-lb electric motor can get the same horsepower as a V-8 block that weighs ten times as much.

The best thing about this car might be its price tag: $95,000. For the styling, performance, and ridiculously low fuel costs, it’s a steal.

The presentation I saw had a comparison between their technology and other forms of propulsion. Electric cars really do make fuel cells and biofuels look silly. For example, hydrogen fuel cells are about 25% efficient, while Li-Ion batteries are about 85% efficient. Fuel cells really are stupid, because you’re using electricity to make hydrogen, essentially using hydrogen as a battery. Why not just use a battery as a battery?

Another graphic showed the area required to fuel the US’s driving for a year if you used corn-based ethanol, cellulose-based ethanol, and photovoltaics. Ethanol covered most of the Midwest, while photovoltaics covered a barely-discernable rectangle.

It’s easy to get excited about new technology, like fuel cells or biofuels, but sometimes it’s far better to get excited about new applications of old technology. I’ll be watching Tesla Motors, perhaps a decade from now they’ll be king of the roads.

(If you want to learn more about the car/company, here’s a Wired article from earlier this year.)

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