Plug-In Hybrids Aren't Coming, They're Here

Wired is running a story about the small but vocal, and growing, number of people who aren't waiting for automakers to deliver plug-in hybrids. They're shelling out big money to have already thrifty cars converted into full-on plug-in hybrids capable of triple-digit fuel economy. "The conversions aren't cheap, and top-of-the-line kits with lithium-ion batteries can set you back as much as $35,000. Even a kit with lead-acid batteries — the type under the hood of the car you drive now — starts at five grand. That explains why most converted plug-ins are in the motor pools of places like Southern California Edison... No more than 150 or so belong to people like [extreme skiing champion Alison] Gannett, who had her $30,000 Ford Escape converted in December. Yes, that's right. The conversion cost more than the truck."

Comments

Efficiency

[Anonymous Coward]

Doesn't efficiency call for a better designed vehicle, rather than just a different fuel source?

Re:Efficiency

[LackThereof]

she's just shifting the emissions to a power plant, which may end up being worse than burning fuel in her car

You're mistaken here, for the simple fact that internal combustion engines are horribly inefficient. You're lucky to get 20% efficiency out any car engine, most of the energy in the gasoline/diesel/ethanol is given off as waste heat.

Electric motors run closer to 90% efficiency, and most of our fossil-fuel power plants are pushing 40% efficiency now; some new natural-gas plants are even hitting 60%.

That's a big difference.

I'm not sure I'd call that being here

[Trepidity]

A tiny number of wealthy people custom-retrofitting cars at uneconomical cost isn't really what advocates of plug-in hybrids have in mind, so I wouldn't say the concept is "here" yet.

Re:Whole lot of stupidity

[paul248]

Maybe you're just being short-sighted. If our goal is to eliminate our dependence on oil for transportation, then commercializing (partially) electric storage and drive systems is certainly a step in the right direction.

Re:Why the absurd fixation on batteries?

[gmarsh]

They don't have better energy density. 160Wh/Kg for LiOn beats the pants off anything in production by Maxwell Technologies. EEStor claims ridiculously high energy density in their ultracapacitors, but I'm skeptical for now until their technology leaves the lab.

Another thing is, batteries tend to keep their voltage as you discharge them - a LiOn cell may drop from 4 to 3.5V from full to 10% charge. Capacitor voltage is set by E=0.5CV^2 - an ultracapacitor charged to 2V will be down to 1V at 25% charge.

Pulling "usable" energy (reasonably constant voltage) out of ultracapacitors requires wide-input-range switching power supplies. These require larger inductors, bigger transformer cores, etc. and are less efficient than narrow range SMPS. The charging circuitry for ultracapacitors will also be less efficient than LiOn charging circuitry for the same reason.