- #1
Grinkle
Gold Member
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- TL;DR Summary
- What is Tesla equivalent miles per gallon comparing at the macro level?
From here -
https://www.fueleconomy.gov/feg/noframes/39769.shtml
I see:
1 gallon of gasoline burned in an internal combustion auto engine will yield 33.7 kWh of usable work - is that what this means?
I am trying to get my head around whether e-vehicle use takes more fossil fuel or less fossil fuel than gasoline / Diesel engine use. Because electricity is generated from fossil fuel, I want to immediately conclude that the 2nd law of thermodynamics says that I don't need to think very hard on it, electricity must use more fossil fuel than burning raw fossil fuel directly - but a conversation with a friend has me uncertain.
If it is the case that a large generator can be very efficient at turning fossil fuel into electricity, and there is not much loss in the distribution, then perhaps the efficiency of the electric vehicle engines can be better enough relative to gasoline engines that in the net it takes less fossil fuel to generate and distribute and utilize an electric vehicle than a gasoline vehicle.
Is this known either to be the case or to not be case, or is this conclusion very judgement driven and hard to quantify?
I must also consider the below, which surprised me so I am glad I looked it up. Only 63% of electricity in the US is generated from fossil fuel. I mistkenly thought it was closer to 90%.
https://www.eia.gov/tools/faqs/faq.php?id=427&t=3
So I think that means if I am looking for the break-even point on fossil fuel consumption, I must give e-vehicles an approximate 30% margin in the above net calculation thinking if I am not talking about a hypothetical situation where the only root source of usable work is fossil fuel.
https://www.fueleconomy.gov/feg/noframes/39769.shtml
I see:
1 gallon of gasoline burned in an internal combustion auto engine will yield 33.7 kWh of usable work - is that what this means?
I am trying to get my head around whether e-vehicle use takes more fossil fuel or less fossil fuel than gasoline / Diesel engine use. Because electricity is generated from fossil fuel, I want to immediately conclude that the 2nd law of thermodynamics says that I don't need to think very hard on it, electricity must use more fossil fuel than burning raw fossil fuel directly - but a conversation with a friend has me uncertain.
If it is the case that a large generator can be very efficient at turning fossil fuel into electricity, and there is not much loss in the distribution, then perhaps the efficiency of the electric vehicle engines can be better enough relative to gasoline engines that in the net it takes less fossil fuel to generate and distribute and utilize an electric vehicle than a gasoline vehicle.
Is this known either to be the case or to not be case, or is this conclusion very judgement driven and hard to quantify?
I must also consider the below, which surprised me so I am glad I looked it up. Only 63% of electricity in the US is generated from fossil fuel. I mistkenly thought it was closer to 90%.
https://www.eia.gov/tools/faqs/faq.php?id=427&t=3
So I think that means if I am looking for the break-even point on fossil fuel consumption, I must give e-vehicles an approximate 30% margin in the above net calculation thinking if I am not talking about a hypothetical situation where the only root source of usable work is fossil fuel.