Thursday, July 8, 2010

Solving electric cars

People moan about electric cars having poor range and long recharge times. Those are, basically, the two issues stopping every driver in America from having an electric car right now. Take those two issues off the table, and electric cars are superior in every way. Namely, a far superior torque curve which allows them to have a much simpler design, resulting in less weight. They're not only quiet, they're almost entirely silent (only a downside if you're a blind pedestrian), and, of course, they are emission-free (which really means that their emissions are coming from the electric power plant that's charging their batteries, but that's still better given that that plant will have much better emissions controls).

I don't have a solution to the range issue, but the time-of-charge issue can be tackled fairly straightforwardly.

Lots of devices we use on a daily basis are battery operated, and most of them take batteries that are field-replaceable consumables. It's so common to replace a pair of AA batteries in a device we don't hardly think about it anymore.

It used to be that backyard gas grills that run on propane tanks required you to take the empty tank to a propane filling station. But in the last few years, this has been replaced with propane tank swapping stations at many grocery stores and pharmacies.

By now, I think most of you can see where I'm going. Electric cars could be designed to have their battery packs quickly exchanged instead of field-recharged. You'd go to a battery exchange and swap your drained battery for a fully charged one. You'd pay for the cost of charging, plus perhaps a small amortization of the cost of replacing packs once their useful service life has elapsed.

Swapping out a battery module, if the process is properly designed, could be done in about the same amount of time as filling up a tank of petroleum distillate, and the danger of fire and explosion would be markedly reduced.

The downside is the design engineering involved in coming up with an industry standard battery pack and getting the entire industry to agree on it. Additionally, like all alternative fuel arrangements, it creates a chicken-egg problem where you won't have the fueling infrastructure in advance of the ubiquity of the vehicle and vice-versa.

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