Aug 11 2009, 5:01PM
The Freaky Math of Plug In Hybrids
Times have changed: the once-mighty GM seems to be live blogging its "game changing" Chevy hybrid electric VOLT today, claiming its $40K price is justified by its 230 mpg EPA rating. But that number, like so many numbers associated with plug in hybrids, is less impressive than it seems. The charming dorks at Environmental Economics point out that the Volt gets 230 mpg when the trip length is exactly 51.11 miles, but for a trip of 200 miles the car gets 62.5 mpg, which is not much better than my diesel VW Golf, purchased used for around $15K. Of course, there's a lot to love about Plug In hybrids, and GM's new game, but the numbers around them are vexing.
Rickety math wouldn't be a problem if it weren't for the fact that we're trying to fashion an energy policy out of the dream of having a million electric and plug in vehicles on the road by 2015. (More math: today we have only 2000 capable of sustaining freeway speeds, according to cleantechblog. So we're looking at 5000 percent growth in six years. Talk about your hockey stick inflection point!)
But the other problem with plug in hybrids, in particular, is that their gas mileage depends heavily upon the behavior of the driver. As I wrote for Forbes, one person can coax more than 99 mpg out of a modified plug in Toyota Prius, while a pedal-to-the-metal type who forgets to plug the thing in at night will get less than 40 mpg. A study by Argonne National Lab found that driving style alone can reduce the electric range of a vehicle from 40 miles to 15. The numbers get even dicier from there out, because charging a plug in Prius in a state that's got a lot of coal fired electrical generators turns out to be not much better from a greenhouse gas emissions perspective than just using gasoline.
Plug in hybrids are a great idea for Detroit, and for the rest of us too, but they are not a silver bullet for the problems of energy security and greenhouse gas emissions. And they're really not solid enough to base an energy policy around.
We can all drive more fuel efficient cars starting today without spending a dime – it’s a matter of adjusting our driving habits. I learned a ton at an eco-driving workshop at this summer’s Midwest Renewable Energy Fair. Check out the top ten tips at http://digginginthedriftless.wordpress.com/2009/06/23/10-ways-to-cut-gas-costs-and-save-the-planet/
Happy gas savings,
Denise Thornton
http://digginginthedriftless.wordpress.com
I agree with you, that the volt has WAY to large a price tag. Electric cars are amazing things- they can help our economy, they can create jobs, they can help us save money in our pocket, they are a little better for the environment. But none of that matters if they are too expensive for people to buy.
As for GMs MPG rating, I don't think we should even be discussing it, we should be discussing 100% electric cars. Electric cars are lighter, less maintenance, more efficient, cleaner, and potentially less expensive than hybrid cars. And GM has experience building 100% electric cars with the GM EV-1 (this is why I get so mad at GM) Not many people now the history of GM, but they did infact build a working electric car in the 1990s called the GM EV-1 (Danny DeVito and Bill Nye were 2 of many who leased it). GM decided to refuse to let leasers continue to lease it, took them into the desert, and crushed them. GM then sold the patent for the electric car batteries (NiMH) to Chevron. Chevron sued Toyota for using the Battery, and refuses to license the NiMH battery to any auto manufacturer trying to build a 100% electric car. That's why in the last 10 years, when we could have been developing electric cars, we heard nothing about them. That's why auto companies are stuck using li-ion batteries, which are MUCH more expensive, and less suitable, than NiMH batteries. For more information, I suggest reading the book about electric cars,"Two Cents Per Mile" by Nevres Cefo, which you can read excerpts and reviews of an Amazon.com.
As usual, they will spin the numbers however makes it appear that this is the best thing since sliced bread. Unfortunately, as you discussed, the product rarely lives up to the hype.
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Juan
I like the card in this picture of the articale, it is very specail.
Thanks,
Shingles in the Eye