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http://www.autoexpress.co.uk/car-ne...mit-more-lifetime-co2-than-a-petrol-supermini

I've got a few opening salvos:

  • headlines are more hype than reality--it's only in one part of the U.S. (the midwest, where coal-power dominates) that an EV emits more "lifetime" CO2--than the lowly Mitsubishi Mirage.
  • How is the "lifetime" calculated and did they consider the costs of extracting/refining petroleum?
  • I can't even find the study, and the Trancik Lab that is quoted seems all-in on renewables http://trancik.mit.edu/
 

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http://www.autoexpress.co.uk/car-ne...mit-more-lifetime-co2-than-a-petrol-supermini

I've got a few opening salvos:

  • headlines are more hype than reality--it's only in one part of the U.S. (the midwest, where coal-power dominates) that an EV emits more "lifetime" CO2--than the lowly Mitsubishi Mirage.
  • How is the "lifetime" calculated and did they consider the costs of extracting/refining petroleum?
  • I can't even find the study, and the Trancik Lab that is quoted seems all-in on renewables http://trancik.mit.edu/
You seem to forget that Natural gas power plants emitted an average of 549 grams (19 ounces) CO2 per kilowatt hour....Comapred to Coal-based power plants emitted an average of 915 grams (32 ounces) of carbon dioxide (CO2) per kilowatt hour of electricity produced.
 

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Why are we comparing a French jet fighter with a Tesla on a Volt site? :p
 

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Not that we needed it, but yet another reason to get rid of coal plants. At least the article is very up front about the assumptions and limitations. One note is that the grid gets cleaner over time, so to extrapolate into the future the CO2 emissions in the out years would need to be revised downwards. Finally I never understand why studies like these ignore pollutants. Those can kill you or take some IQ points off. Emissions aren't directly harmful in the same way.

Why are we comparing a French jet fighter with a Tesla on a Volt site? :p
+1
 

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I think this statement from the article says it all:

“if we consider the US average electricity mix, the CO2 emissions intensity of the Tesla Model S is significantly lower than that of the Mirage.”

The bias of picking a low population density area fed by mostly coal energy and picking a performance sedan versus a car that can't even get out of its own way, is a clear indication that they just wanted to stir up views by picking worst case for the EV and best case for the "petrol" car.

Mike
 

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If you want to see the zip code by zip code break down use this link

http://www.ucsusa.org/clean-vehicles/electric-vehicles/ev-emissions-tool#z/01886/2017/Chevrolet/Volt

For a 2017 Volt the equivalent MPG emission figures are,
MA 79 (Zip 01886)
Chicago 46 (Zip 60615)
Niagara Falls 99 (Zip 14301)
Sunnyvale 76 (94043)

I don't know what GAS/Electric ratio they were using for the Volt but if you look at the Bolt figures they must have assumed the Volt used a fair amount of gas.

The figures for the Bolt are,
MA 122
Chicago 53
Niagara Falls 190
Sunnyvale 113

It's clear that on the coasts the Volt has fewer emissions than any possible hybrid when run as a mix of gas and electric. If you never use gas then it's the equivalent of a 100 MPG hybrid (The Bolt has a MPGe rating about 15% better than the Volt so I multiplied the Bolt numbers by .85). In the Midwest the Volt and even the Bolt is equivalent to a good hybrid but not quite as good as the best hybrids.
 

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I don't know what GAS/Electric ratio they were using for the Volt but if you look at the Bolt figures they must have assumed the Volt used a fair amount of gas.
And THAT FIGURE is trivial to obtain. VoltStats has a statistically significant number of vehicles in its reporting fleet. All those kind of numbers are on the main page at the bottom of the chart. 94 MPG for the fleet including high-consumption rollers like Sparkie and Volts that never get charged at all, 112 MPG for more typical use case.
 

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Since I typically drive my Volt more like a Bolt, I was more interested in that number. I tried several different zip codes in California and they all gave the same number; it looks to me like it doesn't look at the differences between power companies and likely doesn't account for the time of day that the bulk of charging is done. I know for a fact that when I charge mine (over night) that my power company has an excess of wind power and ramps down their thermal plants as much as is possible.
 

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And THAT FIGURE is trivial to obtain. VoltStats has a statistically significant number of vehicles in its reporting fleet. All those kind of numbers are on the main page at the bottom of the chart. 94 MPG for the fleet including high-consumption rollers like Sparkie and Volts that never get charged at all, 112 MPG for more typical use case.
I was merely stating that I don't know what ration the authors of the chart used, they may very well have used Voltstats number. BTW I do hope that Voltstats will be able to restore their connection to OnStar. Nothing seems to be happening there so I fear that Voltstats is effectively dead.
 

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I was merely stating that I don't know what ration the authors of the chart used, they may very well have used Voltstats number. BTW I do hope that Voltstats will be able to restore their connection to OnStar. Nothing seems to be happening there so I fear that Voltstats is effectively dead.
Do you assume every response is someone picking a fight with you, and you need to justify your post? Sorry, I'll not bother to support your points anymore.
 
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