Prius consumes more energy in lifetime than Cherokee
I thought this article hit a little too close for comfort. If you really want to call yourself an environmentalist, do what my sister-in-law did: Buy a small Toyota hatchback and put 5,000 miles a year on it for two decades.
Then there was this interesting article in the Economist discussing the future of diesel cars in America:
The dirty little secret about hybrids is that their batteries and extensive use of aluminium parts make them costly to build in energy terms as well as financial terms. One life-cycle assessment claims that, from factory floor to scrap heap, a Prius consumes more energy even than a Hummer III. Diesels are unlikely to consume anything like as much over their lifetime. That could change, of course, if some bright spark decides to replace a hybrid’s petrol engine with a diesel–to launch a family car capable of 100mpg. Now there’s a thought.
Actually not, Economist staff writer person. That assessment you refer to says that the diesel Jetta wagon will also use as much energy in its lifetime as the H3. And guess what? In all likelihood that diesel hybrid you cite will too, for the same reasons as the Prius and Jetta. But you would have known that had you bothered to actually read that lifecycle assessment. I don’t blame you, actually. The damn thing is over 400 pages long. I know because I did read it. In fact, I built a spreadsheet with the data I gleaned from it to answer some burning questions I had.
I don’t know how this study slipped past my radar screen. I’ll blame Grist again, thus motivating someone to check the archives so they can rub my face in it. Here is the headline from CNW Marketing Research Inc. (headed by Art Spinella) touting the results of their research:
Hybrids Consume More Energy in Lifetime Than Chevrolet’s Tahoe SUV
This conclusion was drawn from their research on the total energy used to build, maintain, operate, and recycle a car. Who could have guessed that the report was met with praise by SUV enthusiasts (and Detroit in general) and with skepticism by hybrid enthusiasts (Toyota in particular). The validity and methodological robustness of the report took a hit when CNW reviewed it a few months after the press release and concluded that maybe the Tahoe uses a little more energy than first reported (a whopping 30% more), thus consuming more lifetime “dust to dust” energy than hybrids after all. Oh, well, scratch that headline.
To give you a feel for how radical this report’s findings are, consider that a Prius will consume six cents of gas per mile if gas is $3.00 a gallon. This study calculates that a Prius would consume $2.87 worth of lifecycle energy per mile (dust to dust energy) at that same $3.00 value. Here is how it works. Let’s say you need a new alternator. They account for the energy needed to make the new alternator, and to replace and recycle the old one. Simply multiply that methodology as needed to get desired results.
The study still shows that a Jeep Cherokee will use less lifecycle energy than a Prius. Now, my family happens to own a Prius and a Cherokee, so I can’t really lose here. However, as I look into this report, you should expect a case of extreme bias from me considering that I contribute to the best environmental blog on the planet. Bias can be largely subconscious, meaning I can’t do anything about it if I tried. That’s what peer review and the scientific method — of which this post has none (and neither does the study I am about to critique) — are for. Peer reviewing this study won’t be easy. From CNW:
The database used for the Excel spreadsheets is proprietary to CNW and will not be released.
Additional data, other than what is presented on CNW Marketing Research, Inc.’s various web sites will remain unavailable to protect the proprietary nature of the data and the research methodology.
All rights to this information are held by CNW Marketing Research, Inc. Use of this information without prior approval except as noted above is strictly prohibited and will be treated as theft of intellectual property valued at US $25 million.
Anyone wanting data (even subscribers) cannot receive raw data bases. We control how data is released and maintain final approval on how information is presented because too often selective data points are used to “prove a point” rather than being complete, objective or neutral.
Sheesh. We wouldn’t want people proving points now, would we? All the same, I want to at least try to come at this not as an incensed Prius snob but from the perspective that the study is likely to be correct — if not in total, then almost certainly in part. I have always viewed the Prius as a proof-of-concept car demonstrating that environmental benignness can be used as a status symbol, hopefully setting off competition for increasing benignness, eventually leading to cars vastly superior to the Prius. Global warming has made all things environmental much more complicated.
There is nothing more deflating than having someone do extensive research (for two years in this case) and conclude that the car you bought to save the planet, a Prius, consumes more energy on a lifecycle basis than the dreaded Hummer II (a conclusion that also changed when the authors took a second look). I have done my share of status symbol bubble popping. I have pointed out the negatives of trading in a gasoline car for one that burns soy-based biodiesel, the futility of putting PV panels on a Seattle house, and the self-nullifying nature of building energy efficient rural McMansions. For all of you out there who have done those things and then read my posts after the fact … I now feel your pain and beg your forgiveness.
This post is already long, so I am going to present some basic conclusions now before it is too late. Also, I am going to limit my conclusions to the Prius, because I own one and want to balance the bias created in the study when they lumped a bunch of hybrid drive system cars together.
1) Trust me, there is nothing in this study to lose sleep over. My spreadsheet shows that in most cases, the energy costs will come way down as the number of cars sharing this technology grows over time. Things like low-weight steel, large batteries, and hybrid drive trains will become the norm if we progress to cars like diesel plug-in hybrids and hopefully from there to all electric. Another positive note is that the study shows the Prius is better than the industry average for all cars in the study, even with all of these temporary disadvantages that saddle any new technology at first.
In a nutshell, the results of the study show that the fancier the car, the more energy will be required to produce, maintain, and recycle it. There isn’t an official category for “fancy” car, so its definition is in the eye of the beholder, but one can easily conclude that the Prius is a fancy car. A curvy sports car smaller than the Prius may use more lifetime energy as does a giant slab-sided Hummer II but for different reasons. The Hummer loses because it is so huge and eats a ton of gas. The sports car loses because it has unique parts that are energy-intensive to manufacture and dispose of (similar to the Prius, which also has technological start up energy costs).
2) The study contains its share of bias. But then, what study doesn’t? If an author expected (hoped for, wanted) a study to show that cars (and hybrids in particular) use more energy on a lifetime basis, then the hundreds of assumptions made would tend to be subconsciously skewed to get that desired result. Spinella has to be glad he got the results he did. His company has received tremendous exposure from press interest. In other words, he didn’t just stumble onto these results: he went looking for them to prove a point. He suspected hybrids might be worse than many regular cars for total lifetime energy and that is why he initiated the study.
Spinella knows what he is doing, having funded this study out of his own pocket to avoid the inevitable accusation of being called a shill for big whatever. You could argue that he is still kowtowing to Detroit, who has probably buttered much of his bread, but I don’t think that is the case. Judging from the many comments I have read he just isn’t a big fan of hybrids.
I found this little blurb on the topic of bias at Oxford’s Future of Humanity Institute:
I warn students that most studies have an agenda associated with their focal factor; the authors, funders, and referees have answers they expect and want to see. Authors can manipulate the statistics to get the answer they want, and funders and referees can refuse to publish unwanted answers.
3) If you own a Prius, relax. Because the Prius presently has high status, it has replaced a lot of other high-status cars that would have been even more energy intensive (lifetime and otherwise) and it also has some of the lowest emissions of any gas-powered car you can buy. If total lifetime energy expenditure were all that mattered to most consumers, we would all walk, ride bikes, or still be driving the same car we bought twenty years ago like my sister in law. In addition, for all of you patriots wanting to cut U.S. dependence on foreign oil, a Prius will do it because most of the energy cost of manufacture is in Japan! Driving a Hummer with a support our troops sticker on it is still an oxymoron. The energy costs associated with building the Prius drop with every car made, so it may be only a matter of time before those energy costs become some of the very lowest.
4) This study could have different effects. If it is propagated by the media as gospel as has been done for ethanol and biodiesel, then it could help kill hybrid technology, the plug-in, and electric cars, locking us into Detroit’s bottom line, big, high-profit, conventional cars. The initial high-energy costs of new technology force manufacturers to use more energy to build things like robots and to do research. But, over time these energy costs will dissipate. Any technology that breaks us free from the internal combustion engine must run this energy gauntlet first.
Another possible effect is that Toyota may take the report seriously, rather than continue to poo-poo it, and rapidly develop a hybrid that is also the world’s most lifecycle energy efficient car. One of the lowest energy consumers in the report is a Scion xA (0.79 energy dollars per mile). Stuff a hybrid drive system in that puppy and compare it to a Hummer (3.585 dollars per mile)!
5) The conclusions are unlikely to be completely off the mark for cars in general. Hopefully, it will motivate car designers to do a better job rather than just freeze technology to avoid a temporary energy spike during research and development. I’m just glad I’m not a car designer. Imagine throwing into your design matrix the need to show total lifetime energy consumption will be lower than a competitor! Imagine trying to verify such a thing when concepts as simple as gas mileage estimates are in constant turmoil. When Pimentel tried to show that ethanol and biodiesel are energy negative by accounting for the energy to make things like tractors everyone threw out his studies. If Pimentel’s studies are wrong, then so is this one.
Let me give you just a few examples of how easy it is to bias a study like this. Since facts can be hard to come by, hundreds of assumptions (educated guesses) have to be made. The results of the study are expressed as money spent on energy per mile. So, if your car goes 200,000 miles instead of 100,000, your cost per mile would be cut in half. He chose 109,000 miles for the Prius and 197,000 for the Hummer. Now, he didn’t pull these numbers out of thin air. He owns a marketing research company. They have statistics to use.
It is kind of hard to categorize a Prius. He assumed the Prius is essentially a newer version of a Pinto (a small four-cylinder hatchback). I owned four Pintos in a row as an impoverished college student and not one of them made it much past 100,000. Think about it. A four-cylinder engine has twice the wear as an eight-cylinder one and should wear out a lot faster. However, there are Prius taxies that have passed the quarter million mile mark without a hitch. No Pinto ever did that! How can a four-cylinder engine do that? Well the engine has spent much of its life shut off or at low RPM because it has an electric motor to help it.
Similarly, if you assume a Hummer will be treated like a pickup truck, you can expect that it will be passed along and used to haul lumber and yard waste. But a Hummer is also hard to categorize. It isn’t a truck. It is a phallic symbol for rich guys and it really doesn’t have any other use outside the military. It was designed to haul combat troops, not yard waste. It is also very expensive to maintain. I think it is highly unlikely that most of these single digit MPG pigs are going to be driven very long once the shine wears off and gas goes to five bucks a gallon. Just putting a new set of tires on one of those stupid things would throw most people into hock.
All hybrids are not created equal. You can’t just lump all vehicles with a hybrid drive system together. Locomotives are hybrid vehicles. The Insight, Civic, and Prius are special because of their extraordinary gas mileage. But, because they all also have some kind of hybrid drive train, the public immediately confused the hybrid logo on the back of a car with better gas mileage and even took it a step further to assume it meant environmentally superior.
A hybrid logo does not mean any of those things. Hook an electric motor to a turbo charged V-8, stuff the both of them into a huge truck and you will have a hybrid gas hog that might accelerate faster than a similar truck without the electric motor, but won’t necessarily result overall in less fuel consumption. Marketing firms (similar to CNW) quickly realized that the public had associated (confused) the term hybrid with good things and that is why there are now hybrid vehicles out there that use the system mostly for impressive accelerations instead of impressive gas mileage. Like the “Hemi” logo and biodiesel stickers, people want the hybrid emblem on their car. I met a lady last week who must have told me three times that she also owns a hybrid. Because it happens to be a hybrid SUV, it looks no different from the non-hybrid, which is why she felt compelled to point the fact out.
Visibility is a necessary condition for status. That’s one of the beauties of the Prius. It’s a billboard on wheels.