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Using his numbers, a Prius at 50mpg uses 2 gallons of gas for 100 miles, and produces 30,200 grams of CO2 per 100 miles, less than the coal charged LEAF. Even worse is the reference to electricity required to refine a gallon of gasoline actually says "about 21,000 Btu—the equivalent of 6 kWh", http://gatewayev.org/how-much-electricity-is-used-refine-a-gallon-of-gasoline not the 6 kwh of coal powered electricity which Mr. Larsen used to come up with 6,300 grams of CO2 to refine a gallon of gas. Since 6 kwh of coal powered electricity is not actually used to refine a gallon of gas his numbers would be even worse for EV's, so much so that I think all his numbers must be off and are not a valid reference.
 
JRP3 said:
Using his numbers, a Prius at 50mpg uses 2 gallons of gas for 100 miles...
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Wow, can we drop this yet? Yes, if you assume a 100% coal-powered EV, and compare it against the most efficient ICE vehicle in production, and ignore various externalities of gasoline production, and are only concerned with CO2/mile, the ICE wins. You win. Happy now?
 
The link was posted as a reference, I think it has some seriously flawed data and should not be used as a reference. To be clear I think his numbers come off much worse for EV's than they should, even though he mistakenly used 6kwh's of equivalent energy as coal powered electricity, which should have skewed things more in favor of EV's. I'll "win" when studies and comparisons use more accurate data.
 
Time to thread-jack the data debate back on topic...

I park in my local Fresh and Easy's "hybrid parking only" all the time. I actually do it in hopes that someone will call me out on it. I'd love to hear their arguments :roll:

Alas, no one ever has :lol:
 
JRP3 said:
The link was posted as a reference, I think it has some seriously flawed data and should not be used as a reference. To be clear I think his numbers come off much worse for EV's than they should, even though he mistakenly used 6kwh's of equivalent energy as coal powered electricity, which should have skewed things more in favor of EV's. I'll "win" when studies and comparisons use more accurate data.
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Heh. Okay, then, JRP3: I have updated the information using data from the EPA, and the actual percentages of greenhouse gas emissions from the various types of power plants that make up our electric grid nationwide. Maybe you'll deem the results a bit more acceptable...?

The Ludicrous “Long Tailpipe” Accusation by Petrolpuppets

coalplant.jpg
 
Actually I get combined emissions for the Versa of .814 per mile using the fueleconomy.gov link. 73 + 296 = 369 gr = .814 lbs.
The Prius is 44 + 178 = 222 gr = .4894 lbs
 
Yanquetino said:
The Ludicrous “Long Tailpipe” Accusation by Petrolpuppets

coalplant.jpg
Click to expand...
One incorrect assumption about the LEAF numbers is the battery capacity of 24 kWh. Since only ~21 kWh is usable the kWh for full charge, using the listed efficiencies, would be 24/.87/.93 = 25.95 kWh for a full charge. The lbs. CO2 for a full charge would be 25.95*1.2283 = 31.87 lbs. CO2. Working though the rest of the steps gives 43.66 lbs. CO2 per 100 miles using a grid average CO2 output.
 
JRP3 said:
Yes that seems more in line, and puts a Prius only slightly below a grid mix charged LEAF for CO2 emissions.
http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=31715&id=31767&id=32154&#tab2" onclick="window.open(this.href);return false;
The only caveat of course is if you assume night time charging which is not the same as grid mix and skews more heavily towards coal and higher CO2 emissions.
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True! But the grid mix I cited is *not* specified for only daytime hours. So while there might be more coal at night, there might be less coal in the day. I can only assume that the percentages listed represent a 24-hour "average." Do you have data showing different percentages for day and night?

Seems to me... it's pretty much a wash, regardless, and about as close as we're going to get.

And my point down below on the page still stands: those "long tailpipes" are still smokin' away at night anyway, whether not EV owners are charging their vehicles. Consequently, they're not "adding" to the amount of CO2 produced: they're merely putting the excess energy to good use rather than wasting it. In that regard, EVs should get to subtract the amount of greenhouse gases attributed to them if they charge while we're asleep. :)

With the Prius, yup, that's right: it apparently emits about a pound and a half less CO2 than a Leaf per 100 miles driven. I am thinking that might :?: be because it gets its electricity from petroleum, which produces much less CO2 per kWh than the entire grid mix. That won't be the case as the grid gets cleaner over time, of course. And certainly not for EV owners with solar panels. And even now not with the i-MiEV, as you can see if you run its utility down below.

As for your very slightly different calculations above, I assume they are likely attributable to mere decimal points. I use the "standard" 19.40 lbs. of CO2/gallon from a tailpipe in my calculations. That ends up being about 8,800 grams. When I divide that by the Versa's 30 mpg, I get 293.33 grams/mile instead of the 296 grams/mile that its EPA page states. I just don't think it is worth quibbling about those 2.66666666666667 grams/mile (0.00587899365826 lbs.!).
 
dgpcolorado said:
One incorrect assumption about the LEAF numbers is the battery capacity of 24 kWh. Since only ~21 kWh is usable the kWh for full charge, using the listed efficiencies, would be 24/.87/.93 = 25.95 kWh for a full charge. The lbs. CO2 for a full charge would be 25.95*1.2283 = 31.87 lbs. CO2. Working though the rest of the steps gives 43.66 lbs. CO2 per 100 miles using a grid average CO2 output.
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I don't think that's correct. I have already included the "useable" charge in my figures, but it is not readily apparent on the surface. You see, I am basing my calculations on the EPA's 73 mile range for the Leaf, which already depends upon it "useable" charge --not the full 24 kWh. Moreover, even though only the useable 21 kWh achieves that range, the EVSE is putting 24 kWh into the pack. Hence, backing up the lines to the power plant, the amount of CO2 it produces is still based on 29.66 kWh.
 
Yanquetino said:
dgpcolorado said:
One incorrect assumption about the LEAF numbers is the battery capacity of 24 kWh. Since only ~21 kWh is usable the kWh for full charge, using the listed efficiencies, would be 24/.87/.93 = 25.95 kWh for a full charge. The lbs. CO2 for a full charge would be 25.95*1.2283 = 31.87 lbs. CO2. Working though the rest of the steps gives 43.66 lbs. CO2 per 100 miles using a grid average CO2 output.
Click to expand...
I don't think that's correct. I have already included the "useable" charge in my figures, but it is not readily apparent on the surface. You see, I am basing my calculations on the EPA's 73 mile range for the Leaf, which already depends upon it "useable" charge --not the full 24 kWh. Moreover, even though only the useable 21 kWh achieves that range, the EVSE is putting 24 kWh into the pack. Hence, backing up the lines to the power plant, the amount of CO2 it produces is still based on 29.66 kWh.
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Not true I think. If 3 kWh of the pack is not accessible you don't have to replace it when charging*. The 73 miles of range comes from, at most, ~21 kWh of energy added to the battery pack after being fully depleted to turtle (not including efficiency losses that you calculate separately).

An assumption that the EPA range is based on 24 kWH usable energy would mean that the 73 mile range is 12.5% too high. Is it really reasonable to assume a 64 mile range for a LEAF? I think not.

*[Some of the "missing" 3 kWh is energy below turtle that can never be accessed. Some is charge above "100%" that the battery management system will never allow to be filled because it would shorten the life of the battery pack.]
 
Yanquetino said:
dgpcolorado said:
One incorrect assumption about the LEAF numbers is the battery capacity of 24 kWh. Since only ~21 kWh is usable the kWh for full charge, using the listed efficiencies, would be 24/.87/.93 = 25.95 kWh for a full charge. The lbs. CO2 for a full charge would be 25.95*1.2283 = 31.87 lbs. CO2. Working though the rest of the steps gives 43.66 lbs. CO2 per 100 miles using a grid average CO2 output.
Click to expand...
I don't think that's correct. I have already included the "useable" charge in my figures, but it is not readily apparent on the surface. You see, I am basing my calculations on the EPA's 73 mile range for the Leaf, which already depends upon it "useable" charge --not the full 24 kWh. Moreover, even though only the useable 21 kWh achieves that range, the EVSE is putting 24 kWh into the pack. Hence, backing up the lines to the power plant, the amount of CO2 it produces is still based on 29.66 kWh.
Click to expand...
Hmmm. The more I thought about this, the more I think you're right, dgpcolorado. :) I was stuck on thinking of the Leaf's battery pack as fresh from the assembly line, totally empty --which would take the full 24 kWh to fill it for the first time. Yet it is true that, after being driven for its full 73 mile range, there would still be 3 "unuseable" kWh in that pack. So charging it with the EVSE would only put 21 kWh back into it.

What finally clicked for me was to take the 73 mile range, divide it by the useable 21 kWh, then times that by the full 24 kWh to see what kind of range would be theoretically possible if one could somehow tap into the pack's total capacity. When I then divided the plant capacity I had originally calculated by that theoretical range... the results matched what you were showing. Ergo... at the factory, when charging the pack for the first time, the amount of CO2 generated upstream... would be the same per mile.

I have made that change to the webpage and software! And appreciate the help!

Oh... and JRP3: with that change... the Leaf now "beats" the Prius! :D
 
Beats the Prius a lot on what is added to the local pollution.

Did the gas "long" tailpipe count all the evaporation and spillage along the way?

How about the gas/oil used in "oil" wars and the production of war materials for those wars?

How about the training and maintaining of forces anticipating those wars?

How about the energy and pollution "costs" of building and maintaining the oil/gas supply line, storage, and delivery: in ships, tanks, pipes, trucks, and their support and supply?

Without the "black opium" industry to support, a HUGE section of the world's economy could be devoted to better things: perhaps building and maintaining parks!
 
garygid said:
Beats the Prius a lot on what is added to the local pollution.

Did the gas "long" tailpipe count all the evaporation and spillage along the way?

How about the gas/oil used in "oil" wars and the production of war materials for those wars?

How about the training and maintaining of forces anticipating those wars?

How about the energy and pollution "costs" of building and maintaining the oil/gas supply line, storage, and delivery: in ships, tanks, pipes, trucks, and their support and supply?

Without the "black opium" industry to support, a HUGE section of the world's economy could be devoted to better things: perhaps building and maintaining parks!
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We don't know if the EPA's "upstream" emissions for gas cars include everything that should be included (drilling, extracting, pumping, etc.), although one response to my web page claimed that its information comes from the GREET model --which supposedly is pretty comprehensive.

You can BET, however, that they haven't included all the figures from wars and military policing to keep our "drug" supply coming, nor the costs to us tax payers because of the subsidies to the richest companies in history. :evil:

What...? You don't think the Oregon militia will soon be invading California to conquer its wind and solar farms? :lol:
 
Whoa...! Here is a widget from SMUD to compare CO2 lbs. between EVs and ICEs:

http://c03.apogee.net/contentplayer/?utilityid=smud&coursetype=misc&id=18862" onclick="window.open(this.href);return false;

The differences between my software's results and what this widget tallies are enormous! :eek: They can't be right, can they? Am I missing something here?
 
Yanquetino said:
Whoa...! Here is a widget from SMUD to compare CO2 lbs. between EVs and ICEs:

http://c03.apogee.net/contentplayer/?utilityid=smud&coursetype=misc&id=18862" onclick="window.open(this.href);return false;

The differences between my software's results and what this widget tallies are enormous! :eek: They can't be right, can they? Am I missing something here?
Click to expand...

That is a really shitty widget.
 
Yanquetino said:
True! But the grid mix I cited is *not* specified for only daytime hours. So while there might be more coal at night, there might be less coal in the day. I can only assume that the percentages listed represent a 24-hour "average." Do you have data showing different percentages for day and night?
Click to expand...
I can't find solid data, but "grid mix" uses available generating capacity, much of which is shut down, or turned down at night.

And my point down below on the page still stands: those "long tailpipes" are still smokin' away at night anyway, whether not EV owners are charging their vehicles. Consequently, they're not "adding" to the amount of CO2 produced: they're merely putting the excess energy to good use rather than wasting it.
Click to expand...
My understanding of the grid does not support that assumption. NG plants do not keep "smokin' away at night", they throttle way back or shut down. Coal plants also throttle down some. Nuclear is baseload and keeps putting out close to rated power I think. Hydroelectric is tricky, as it's both baseload and peak load. Hydro can be throttled back at night to bank up capacity for peak use during the day, that way peak hydro, which is cheap, can be used instead of peak NG, which is more expensive. So while hydro might be able to throttle back up in some areas at night to fill in the extra load of a fleet of EV's plugging in, it's more likely that coal will be kept up higher at night to allow the hydro to be banked for daytime peak loads. Bottom line is it appears that most additional night time marginal load will be provided by coal in many areas, pushing the over all CO2 mix for night charged EV's higher than the overall grid mix.
 

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