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Sunil Somalwar, a physics professor at Rutgers University, presents the following argument at the Better World Club site:
Let us conservatively say that a Prius goes 40 miles on a gallon of gasoline. After taking into account the 20 lbs CO2 released by burning a gallon of gasoline, 40mpg amounts to two miles per pound of CO2 emission. On the other hand, a plug-in electric car may not emit any CO2 from the tailpipe, but when I draw a kilowatt-hour from the electric grid here in New Jersey to charge the car batteries, a coal plant in some other state belches out 2.5 lbs of CO2. According to Toyota, the plug-in version of the Prius will run about 2.5 miles on that kilowatt-hour of electricity, which means that I get only one mile per pound of CO2 emission. When I plug it in, my 40-50 mpg Prius becomes half as efficient and turns into a 20 mpg SUV. (The story with GM's upcoming Volt plug-in car is no different.)
Here's the rest of the story (it's pretty short). Has the good professor overlooked anything?
Comments
Posted 7/18/08 4:24 PM by ej
The most obvious blunder this professor has made is to claim that the Prius (or the Chevy Volt) gets 2.5 miles from a kilowatt of power. The Volt, just like any 3100 pound electrically propelled vehicle, gets about 5.5 miles per kilowatthour. He is no doubt confused because he saw that the Volt's battery pack has a 16 kilowatthour capacity and the Volt travels 40 miles on battery power alone (which is enough, interestingly enough, to avoid 94% of gasoline during commuting and 95% for other activities, even without workplace recharging). However, the Volt's battery pack is never allowed to go beyond 80% charge nor drop below 30% charge, meaning that only the middle 8 kilowatthours are actually being used. This is to allow for a 10-year-plus battery pack life. The professor has made the same mistake many others who are unfamiliar with the Volt design have made.
As to the idea that the only reason for electric cars is carbon reduction, that's totally absurd. Crude oil avoidance is the number one reason people want to go electric, not carbon reduction. Dependence on crude is a far more imminent threat and one about which there is no debate. There's plenty of debate about the need or effects of any carbon reduction. (I just read a paper by Australian astrophysicists who claim that a 1 to 2 degree centrigrade drop in temperatures will occur during this decade and will last for over 30 years, and that this always occurs when the Jovian planets are in alignment, causing the sun to stay outside of the center of the universe. I'm waiting to hear contrary arguments, but so far haven't heard a peep.)
If nuclear plants hadn't been stymied for the past 30 years and coal plants built instead, there wouldn't even be any concern about carbon levels. Any carbon induced global warming has been caused primarily by anti-nuclear environmentalists. That's easy to prove.
As to the idea that the only reason for electric cars is carbon reduction, that's totally absurd. Crude oil avoidance is the number one reason people want to go electric, not carbon reduction. Dependence on crude is a far more imminent threat and one about which there is no debate. There's plenty of debate about the need or effects of any carbon reduction. (I just read a paper by Australian astrophysicists who claim that a 1 to 2 degree centrigrade drop in temperatures will occur during this decade and will last for over 30 years, and that this always occurs when the Jovian planets are in alignment, causing the sun to stay outside of the center of the universe. I'm waiting to hear contrary arguments, but so far haven't heard a peep.)
If nuclear plants hadn't been stymied for the past 30 years and coal plants built instead, there wouldn't even be any concern about carbon levels. Any carbon induced global warming has been caused primarily by anti-nuclear environmentalists. That's easy to prove.
Posted 7/18/08 5:12 PM by kent beuchert
At least he seems to accept that the Prius itself is making a positive contribution. Here in the UK many folk including most journalists have not even managed to get themselves that far. I agree that there are many reasons for owning a Prius or an electric car, beyond just emission levels. Still, we don't want to make matters worse, do we?
Where does the commenter above get his information about the Volt? I thought the production design of this semi-mythical marketing tool had not even been finalised yet?
Where does the commenter above get his information about the Volt? I thought the production design of this semi-mythical marketing tool had not even been finalised yet?
Posted 7/19/08 2:55 AM by JerryW
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http://lists.mutualaid.org/pipermail/sustainableto...
Several people brought up the obvious point that it depends on how you are recharging your battery (e.g. off grid system, green power sources, etc). Also, even in the case of coal powered plants, most plug-ins will most likely be plugged in at night, when excess electricity is already generated anyhow -- i.e., the coal is being burned regardless (because it's too costly and inefficient to power down a plant temporarily on a daily basis). Right now, a considerable amount of that energy powers NOTHING, so by using it to recharge batteries, at least you're getting something useful for all the CO2 you're emitting.
I've run across a number of discussions of this on-line -- here's a TreeHugger take:
http://www.treehugger.com/files/2008/04/plug-in-hy...