Embodied Energy: Prius Vs. Hummer

Reader Contribution by Sebastian Blanco
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I got an email from a relative with claims that scientific studies have proven that a Toyota Prius consumes more energy over its lifetime than a Hummer. Can this be true?

Wow, this brings me back to a simpler time, when the Internet was ablaze with reports of a study that proved?–?proved!?–?that it was better for the Earth to drive a Hummer than a Prius. If that sounds absurd, it’s because it is. But just because something is wrong doesn’t mean it leaves the Internet. In fact, that’s where untrue things seem to live on forever.

In 2006, a group called CNW Marketing Research said that even though a 50-mpg Prius doesn’t suck down a lot of fuel to move from place to place, the extra energy and resources required to build, drive and then recycle one?–?especially its nickel-metal hydride batteries?–?require more embodied energy than the notorious symbol of automotive excess: a Hummer.

Since the “study” first hit the Web six years ago, plenty of organizations have debunked it.

Dr. Peter H. Gleick of the Pacific Institute, a nonprofit that works for a healthier planet and sustainable communities, issued his own paper, saying, “Reading CNW’s report and the accompanying pieces they provide reveals numerous misuses of facts and data.”

A leading science-based nonprofit, the Union of Concerned Scientists (UCS), pointed out that a common life-cycle assessment calculation is that 85 percent of embodied energy use associated with a conventional vehicle’s life cycle is attributable to operation and 15 percent is attributable to manufacturing and disposal. Given that, UCS says, it’s unlikely that a 50-mpg hybrid could be worse for the environment than a 17-mpg Hummer H3, even if it took twice as much energy to make the hybrid and it is driven half as much before it is replaced. Toyota concurs with that ratio, and noted that the CNW study reversed the 85 and 15 percentages.

David Friedman, deputy director of the Clean Vehicles Program at UCS, laughed when I asked him about this urban legend. He wondered whether CNW had updated the paper yet again (the organization did so in 2007 and 2008). I told him CNW hadn’t, but people still stumble upon the report all these years later.

“I think it has legs,” he says, “because it has been marketed well. There is a lot of good marketing about this report, not a lot of good science. I will always support efforts to question things that seem obviously true, but for this one, they have never revealed their methodology.”

In the end, while it is true that the Prius runs on gasoline, a fossil fuel, and all the parts that go into it come from finite resources, plenty of analyses have shown that CNW’s original claim?–?that a Hummer is better for the Earth than a Prius?–?is false. It will remain false, no matter how many times your gullible uncle hits “Send.”

?Sebastian Blanco, Editor, AutoblogGreen.com, part of AOL Autos

Photo courtesy GM