The Freaky Math of Plug In Hybrids

More

plug in car.JPGTimes 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. 


Jump to comments
Presented by

Lisa Margonelli is a writer on energy and environment. She spent four years and traveled 100,000 miles to write her book, "Oil On the Brain: Petroleum's Long Strange Trip to Your Tank." More

Lisa Margonelli directs the New America Foundation's Energy Productivity Initiative, which works to promote energy efficiency as a way of ensuring energy security, greenhouse gas emissions reductions, and economic security for American families. She spent roughly four years and traveled 100,000 miles to report her book about the oil supply chain, Oil On the Brain: Petroleum's Long Strange Trip to Your Tank, which the American Library Association named one of the 25 Notable Books of 2007. She spent her childhood in Maine where, during the energy crisis of the 1970s, her family heated the house with wood hauled by a horse. Later, fortunately, they got a tractor. The experience instilled a strong appreciation for the convenience of fossil fuels.

Get Today's Top Stories in Your Inbox (preview)

Social Security: The Greatest Government Policy of All Time?

It's the most effective anti-poverty program in U.S. history. So why do some people hate it?


Elsewhere on the web

Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register. blog comments powered by Disqus

Video

Adventures in Legal Weed

Colorado is now well into its first year as the first state to legalize recreational marijuana. How's it going? James Hamblin visits Aspen.

Video

What Makes a Story Great?

The storytellers behind House of CardsandThis American Life reflect on the creative process.

Video

Tracing Sriracha's Origin to Thailand

Ever wonder how the wildly popular hot sauce got its name? It all started in Si Racha.

Video

Where Confiscated Wildlife Ends Up

A government facility outside of Denver houses more than a million products of the illegal wildlife trade, from tigers and bears to bald eagles.

Video

Is Wine Healthy?

James Hamblin prepares to impress his date with knowledge about the health benefits of wine.

Video

The World's Largest Balloon Festival

Nine days, more than 700 balloons, and a whole lot of hot air

Writers

Up
Down

More in Technology

From This Author

Just In