What I don't hear from news about impact

<div class='quotetop'>QUOTE(priapus the second @ Nov 16 2007, 01:50 PM) [snapback]540667[/snapback]</div>

There have been a number of peer-reviewed life-cycle assessments. See especially #3 below:

1) The 2001 MIT study called On the Road in 2020: An Assessment of the Future of Transportation Technology used a life cycle analysis that concluded that increasing fuel efficiency with hybrid technology, is a net energy and global warming pollution winner.

2) Andrew Burnham, Michael Wang, and Paula Moon at the Center for Transportation Research of Argonne National Labs recently gave presentation called "Energy and Emission Effects of the Vehicle Cycle" at the 2006 SAE World Congress. One of the key the conclusions is "Total energy cycle energy use *decreases* for advanced powertrains & lightweight vehicles. Improved fuel economy offsets increase in vehicle cycle energy."

3) Heather L. MacLean and Lester B. Lave of Carnegie Mellon University published a 1998 life-cycle assessment which concluded that 85 percent of energy use associated with a conventional vehicle's life cycle is attributable to operation. Only 15 percent is attributable to manufacturing and disposal.

4) Sophie Nicolay of the University of Leige in Belgium, published a lifecycle study in 2000 that concluded that the lifecycle environmental impact of electric and hybrid cars is much lower than that of petrol and diesel ones.

 

<div class='quotetop'>QUOTE(priapus the second @ Nov 16 2007, 03:02 PM) [snapback]540694[/snapback]</div>

Well, you can read the complete source article .

Our results indicate that driving an automobile uses much more energy than producing, servicing, or disposing of it. We estimate that service has a large economic impact and an amount of toxic releases similar to the fuel cycle, even though our study is biased toward underestimating the overall impact of service. Laboratory test data on tailpipe emissions and fuel economy give different implications than actual in-use data. We find that exhaust and evaporative emissions of toxics, criteria pollutants, HC, and CO2 continue to be important, even with increasingly strict federal emission standards.

 

<div class='quotetop'>QUOTE(MegansPrius @ Nov 16 2007, 12:18 PM) [snapback]540707[/snapback]</div>

It appears the source is for paid subscribers only. Any other links? Thanks for the additional references by the way.



<div class='quotetop'>QUOTE(priapus the second @ Nov 16 2007, 12:02 PM) [snapback]540694[/snapback]</div>

Huh? How is the school still out? Please post your data. Interested to read your findings that disprove this hypothesis.

 

<div class='quotetop'>QUOTE(priapus the second @ Nov 16 2007, 12:50 PM) [snapback]540667[/snapback]</div>

Ethanol production has improved considerably in the last couple decades, and it appears there's a slight energy gain from corn ethanol compared to energy put in (EROEI - energy returned on energy invested). It's something like 1.3:1, depending on who does the study. However, sugar cane ethanol is much more efficient. Cellulosic ethanol is even better, so if we could use the whole corn stalk, maybe 4:1, I can't remember the actual number (Nat'l Geographic had a recent article on this, if you want something easy to read). But so far it is very expensive to produce large quantities of cellulosic ethanol (don't confuse price with energy returned, there's a correlation but it's not direct, particularly in this area with various taxes and subsidies involved - for one thing we're strongly discouraging Brazilian sugar cane ethanol because of a 50-some cent tariff to keep our corn farmers in business, and to accidentally preserve Brazilian rainforest). Gasoline has an EROEI about 25:1, but in the 80's it was 100:1, when oil was easy to find and recover.

Current technology is not the answer we need to get out of the imported oil problem, but it's a stop-gap until we get the real deal (cellulosic ethanol, better biodiesel) going. I have heard that ethanol has been credited with keeping gas prices somewhat moderated as petroleum prices have increased, since much of the nation uses E10, perhaps unknowingly.

 

Hi Nerfer and Priupus...,

Ethanol is effectively an energy transport medium in the USA right now. The energy used for distillation, is the energy that gets released when the fuel is burned. The solar energy in the corn is only enough to cover its planting and harvest. So, when your drving down the road in E85, its very possible your running your car on Coal from Montana, effectively.

So, why not just liquify the coal? And save the green-house emissions of the farm operations? Or just make electricity from the Coal, and get 80 % effectiveness out of an EV (rather than 10 % out of ICE only car).

True some Ethanol production is looking to use live-stock manure for ethanol production. But until a fossil fuel restriction on "Biofuel" fermentation is implemented, its not really a biofuel. And E85 is a shell game. What walnut shell is the coal and natural gas under!?

Bio-butanol with the new production methods is a much more promissing biofuel. Check out http://www.butanol.com .



Hi Priupus...,

The reason you do not hear much about impact and the Prius anymore, is the marketing agency that put forth this artifice has been soundly shown to be wrong. The articles quoted above, beside rebuttals from the Pacific Institute, and the Rocky Mountain Institute have overwhelmed the attempt to de-market the Prius.

The nickel mine article was found to be full of factual omissions. The mine has been in operation for many decades, and since 1990 has won awards for forest land restoration. The nickel used to make the Prius batteries is a small fraction of the mine's ouput (about 1%). The rest goes for all the other everyday uses of nickel. Such as stainless steel (eating utensils, mass transportation railway cars, corrosion resistant hardware, restaraunt grade and other high-end kitchen equipment), turbine high temperature alloy blades, plating on mechanical and electrical connectors (even the gold plated items have a nickel undercoat), and artificial Chrome on SUV grills and wheels.

 

Megansprius has it right regarding the life-cycle analysis of vehicles. Every study I've ever seen shows roughly that 85% to 90% of the energy is in the fuel, 10% to 15% is in the manufacture and scrapping.

Here's a study from Argonne National Labs, regarding the use of aluminum in cars. If anyone ought to be able to get it right they should. See the graphs, page 10, and note the extensive surrounding discussion on the energy costs of materials used (in this case, aluminum). The data for the Prius are modestly different, in part due to the traction battery, but in larger part due to the much lower use of fuel.

http://www.transportation.anl.gov/pdfs/TA/106.pdf

It's also pretty easy to to put a gross upper bound on the energy in production and scrapping relative to fuel, just by looking at costs. And therefore to convince yourself that the energy required to produce the car can't be hugely greater than the energy in the fuel required to run it.

At $3 gallon, 20 MPG, 150,000 mile vehicle life, a typical US car will burn about $21K in gasoline. Typical car only costs $30K. In the long run, that $30K has to cover all the cost of production, of which energy is just a small part. Even if gasoline is a relatively expensive source of energy, it's clear that the energy inputs to manufacturing can't be hugely higher (and probably are vastly lower) than the energy in the fuel.

There are more precise ways to get at this question, but I could not find a nice calculation all in one place. The direct energy associated with $1 in automobile outputs is only about $0.01. The indirect energy associated with the materials that go into autos is about 5x the direct energy used in the assembly plant. Those are both from reports from the US Congress Office of Technology Assessment, and are about 20 years old. But I doubt that things are that different today. Anyway, put that together, and that means that about 6% of the cost of the car is for the energy required to make the materials and assemble them. For my $30K car above, that would be $1800. Which again is tiny compared to the cost of the fuel.

Basically, every reputable study (ie, not CNW) I've ever seen in this area says the same thing. For cars. And ditto for energy-using home appliances, and so on. Basically, the energy cost in use is far greater than the energy cost in manufacture and scrapping.