Electric cars are cleaner than they are given credit for

[Brian Loves Cars]

This Motor Trend article shows states in which the Volt would be cleaner than the Prius, where the Volt would be cleaner in EV mode or cleaner in ICE mode, etc. I recently posted some back-of-a-napkin calculations converting my Volt in EV mode to equivalent MPGs for CO2, cost, oil consumption, etc.

But it occurs to me - as I'm sure it has occurred to many of you - that in reality the scales tip even more in favor of electric cars during operation. The reason why is simple - the gas burned by the Volt in ICE mode is not the only oil consumed. Oil is needed to move the original oil to a refinery, some oil is burned at the refineries to power the refineries, some electricity is consumed by the refineries to refine the product, and then some oil is used to transport the finished gas to the stations where we pump it.

The relevant questions would be:

0. How much power and oil are used in the process of drilling for oil? (i'd guess this is meaningful)

1. what percent of oil is burned/consumed during the refining process (i'd guess this is meaningful)

2. what percent of oil is burned by tankers transporting it a typical distance relative to the load they are hauling (i'd guess this is negligible)

3. how much electricity is used to produce a gallon of gasoline? This guy thinks its 4-7 kwh/gallon. That is extremely significant and affects arguments of all kinds related to electric vehicles including draws on the power grid, total Co2 (tilting that argument far towards EV's) and more.

The consequences of this are profound if that 4-7kWh figure is accurate.

4. how much oil/gas is consumed in transporting the finished gasoline to fueling stations? I'd guess this is fairly small, although perhaps not negligible.

5. how much electricity is used to pump the gas into cars or down pipelines, etc.? I'd guess this is negligible.

For a really quick (because, frankly, I have not looked into this deeply enough to justify any thorough calculation) if we assume that point 0. above is 0, point 1. above is 0, point 2. above is 0, point 3 above is 5 kWh/gallon, point 4. above is 5%, and point 5. above is 0...

Assume that the Volt averages 38mpg on its ICE, and 4 miles per kWh driving on its batteries...

Pounds of Co2 per kWh = 2.2 (dirty coal power), we'd have
Prius at 50 mpg: 0.6 lbs of Co2 per mile
Volt on ICE: 0.77 lbs of Co2 per mile
Volt in EV mode: 0.55 lbs of Co2 per mile

Pounds of Co2 per kWh = 1.4 (closer to the national average), we'd have
Prius at 50 mpg: 0.52 lbs of Co2 per mile
Volt on ICE: 0.68 lbs of Co2 per mile
Volt in EV mode: 0.35 lbs of Co2 per mile

I know nearly nothing about the refining process, but I suspect that terms 0. and 1. above are probably substantial, and since NONE of the terms above are actually 0...

The Volt, Leaf, or another car operating in EV mode is probably cleaner than the Prius in ANY conditions from a Co2 perspective. Co2 is not too important to me at this time and this stage of my understanding the various arguments about global warming, but oil consumption is. And oil consumption clearly favors the EV's.

Just a thought.

PS: I realize that as of now the manufacturing cost of an electric car tilts this analysis back in favor of conventional cars. The batteries in a Volt, Leaf, or Prius are definitely expensive to make and I'm sure they consume an enormous amount of energy to manufacture before the cars ever get driven, no doubt about it. But in time people will innovate a way to make big, bad, fast charging batteries that are much less expensive to manufacture both in dollar terms and in energy terms. This is a technology at its infancy, after all.

[tboult]

This Motor Trend article shows states in which the Volt would be cleaner than the Prius, where the Volt would be cleaner in EV mode or cleaner in ICE mode, etc. I recently posted some back-of-a-napkin calculations converting my Volt in EV mode to equivalent MPGs for CO2, cost, oil consumption, etc.

But it occurs to me - as I'm sure it has occurred to many of you - that in reality the scales tip even more in favor of electric cars during operation. The reason why is simple - the gas burned by the Volt in ICE mode is not the only oil consumed. Oil is needed to move the original oil to a refinery, some oil is burned at the refineries to power the refineries, some electricity is consumed by the refineries to refine the product, and then some oil is used to transport the finished gas to the stations where we pump it.

The relevant questions would be:

0. How much power and oil are used in the process of drilling for oil? (i'd guess this is meaningful)

1. what percent of oil is burned/consumed during the refining process (i'd guess this is meaningful)

2. what percent of oil is burned by tankers transporting it a typical distance relative to the load they are hauling (i'd guess this is negligible)

3. how much electricity is used to produce a gallon of gasoline? This guy thinks its 4-7 kwh/gallon. That is extremely significant and affects arguments of all kinds related to electric vehicles including draws on the power grid, total Co2 (tilting that argument far towards EV's) and more.


SNIP...


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The data used by MT was based on the Argonne GREET model and EPA data for energy production. It what is called wells-to-wheels and includes most of the upstream energy usage. I'm hoping this year to do a paper on the issues (there are some things missing), but mostly updating to use 2010 or 2011 energy production. MT used the Greet 2010 model, but that is really based on 2007 energy production data... and the grid has gotten a good bit cleaner in that time (at least in CO).


The other issue is that one can pay extra to get cleaner energy. I pay for wind now. Many others go with solar, and and I may add solar this year too.

The electricity used to produce gallon of gas is about 1kw, the remaining 5-6 kw is the other energy used/lost during the process most of which is from NG and petroleum. But that is all included in the GREET model
http://greet.es.anl.gov/

Edit: I just redid the energy computation.. electricity to produce 1 gallon is .17kw (less than 1), see this post
http://gm-volt.com/forum/showthread....313#post130313

[Ross Buchan]

I liked the article in general and it struck me as fair minded. What I don't get is the stated cost of a replacement Volt main battery. You can call any Chevrolet dealer and it says right in their book $3,000. I assume installation would be about $1,000 on top of that but where is Motor Trend getting their cost estimate for the replacement Volt battery? The government subsidizing the Volt battery? That would be news to me.

[volt3939]

Never stated "replacement cost", just "cost", as in initial cost to manufacture IMO. A replacement will most likely be a refurbished one, that's why they want your old one back when it's replaced under warranty. 3K for a refurbished pack sounds about right...

[Ross Buchan]

If that is what they mean it works for me in about 7 1/2 years.

[jeffhre]

I liked the article in general and it struck me as fair minded. What I don't get is the stated cost of a replacement Volt main battery. You can call any Chevrolet dealer and it says right in their book $3,000. I assume installation would be about $1,000 on top of that but where is Motor Trend getting their cost estimate for the replacement Volt battery? The government subsidizing the Volt battery? That would be news to me.

I believe the cost of cells is not included in the price quoted.

[saghost]

I believe the cost of cells is not included in the price quoted.

That's FUD cooked up by the MNL forum. We've had a couple complete battery replacements on the furom - and the dealer charged (so far to the warranty I believe, though they had to be persuaded in one case) the $3k price, for the complete battery.

At that price, GM is almost certainly subsidizing the cost to reduce consumer concerns. But it's a real dealer price for a complete battery assembly. (I wouldn't be surprised if there's a VIN requirement and/or a substantial core charge.)

[DonC]

That's FUD cooked up by the MNL forum.

I agree that we've had a couple get replacement battery packs for $3000 but why would anyone on the MNL forum care? Seems very odd. Not questioning you just wondering what's up with that.