Let me start by saying I've wanted for a long time to use "kerfuffle" in a blog post. The contretemps that's the subject of this post fits the word perfectly. You may remember a few years back that a meme went around stating that the "lifetime energy usage" of a Hummer was less than that of a Prius. As the rumblings had it, this was primarily because of the energy required to manufacture, carry, and dispose of the Prius' battery pack.
The origin of this meme was a report by an entity called CNW Research that is, as best I can tell, a marketing research firm. The report claims to use 3,000 data points to put a price tag on the "dust to dust" (inception of design to manufacture to use to disposal and recycling of the vehicle at its "end of life") energy of a wide variety of vehicles. It's stated that they even include the fuel used driving to work by the employees of the vehicle's manufacturer in their calculations.
They rank many vehicles in a tremendous variety of categories but the phrase that caught on was that the Prius uses more energy from dust to dust than a Hummer.This is despite the fact that the report itself puts these two vehicles in separate categories. CNW Research recommends that the report be used to compare vehicles within a category, not across categories.
On its face, this result seems ludicrous. And Pacific Institute (here) and Slate Magazine (here), among others have strongly criticized the results. CNW Research has defended their results at pages linked here.
Instinct often leads one astray in the field of energy, let's take a brief look. The actual report is available at CNW Research's site in pdf and Excel versions. The pdf is 458 pages and 3 MB so it's a chore.
That said, there are some telling indications to start with, among which are the misuse of units (watts, kilowatt hours, joules, etc.). In fact, they refer to "juelles." Not confidence-inspiring, to say the least. There are strange estimates of vehicle lifetime years of use (e.g., for the H1 34.96 years) with no indication of the source of the number. These numbers are critical because the ultimate number they give is energy cost per mile. The denominator, miles, is found by taking lifetime in years and multiplying by miles per year. There's no indication of the source of either number (other than "CNW Research").
It appears that they use several resales to secondary owners in their cost calculations, though this clearly has nothing whatsoever to do with energy expenditure - I doubt that the writing of a check, and a trip to DMV are significant energy expenditures in the final analysis. And cost is a telling indication. For example, the Prius is stated to have a "life-cycle energy cost" of $3.25/mile. Using the lifetime mileage of 109,000 miles, that means that, exclusive of the materials cost of the Prius, profit for the manufacturer and the various suppliers, distributors, etc., the energy from cradle to grave of a Prius costs over $350,000.
Now, suppose I buy a loaded Prius for $25,000 and drive it 109,000 miles. Using the IRS rate, a decent proxy for all costs of driving (including depreciation, maintence, etc.) and excessive if anything for the Prius, the total cost (not adjusted for time value of money) would be $84,950. Even assuming 100% of that is energy costs, who's paying the other $269,300?
I will acknowledge that "society" pays a significant amount in the form of road maintenance and other public goods. And CNW Research claims to account for these. But it's impossible that this would account for the enormous discrepancy.
All that said, it's clear that CNW Research has invested a lot of time and effort and gathered a spectacular amount of data. I'd like them to be open with it because the conclusions they've reached, correct or incorrect, are quite important. I don't accuse them of bias on the basis of funding, I don't see that kind of skew in their analysis and they claim to have funded it internally. Fair enough, I'll take them at their word.
If this information were to presented as a peer-reviewed publication and the data made available, it would be extremely valuable. I understand that CNW Research wants to profit from their efforts and I'm sympathetic to the profit motive. But the results, as presented, leave ample room for skepticism at best and dismissal at worst. To their credit, they have extensive appendices and answer many questions emailed by readers. Unfortunately, they don't clear up the points listed above.