Tesla

[HPsauce]

.....times generating efficiency of what?

And is transporting fuel efficiency really that low? (I would have guessed high 90's percent)
Typically 3000 gallons in a tanker and it can't have a fuel tank bigger than that to just deliver it locally. Pipelines do the backbone work and are extremeely efficient.

[Goran]

Originally Posted by HPsauce

.....times generating efficiency of what?

And is transporting fuel efficiency really that low? (I would have guessed high 90's percent)
Typically 3000 gallons in a tanker and it can't have a fuel tank bigger than that to just deliver it locally. Pipelines do the backbone work and are extremeely efficient.

generating efficiency is ignored because the source is assumed to be the same for both, be it coal or nuclear.

We can ignore oil tanker because we assume the tanker delivers fuel to the same UK power plant for both electric and fossil fuel cars. So its trucks vs cables for comparing car efficiency. Unless UK has extensive pipe network from refinery to petrol station?

Even if we are extra generous and took out the fuel trucks, you are still faced with 36% for diesel cars vs 58% for electric cars.

[HPsauce]

Originally Posted by Goran

generating efficiency is ignored because the source is assumed to be the same for both, be it coal or nuclear.

We can ignore oil tanker because we assume the tanker delivers fuel to the same UK power plant for both electric and fossil fuel cars. So its trucks vs cables for comparing car efficiency.

Well, sadly no. Your maths are not logical.

[Goran]

Please elaborate.
Ok, crude oil to electricity power plant efficiency is 34% says Siemens, global coal power plant efficiency is roughly 33%
So it makes no difference, you may as well burn the crude oil to generate electricity, skip the refinery step and deliver it to electric cars. Total efficiency comparison is then (ignoring oil extraction which you must do for both)
electric car
0.34 x 0.85 x 0.68 = 0.197

diesel car
0.34 x 0.88 x 0.41 = 0.12

again generously ignoring the tanker trucks.

Please share your calculation.

[HPsauce]

I'd not include the 0.34 in the diesel calculation. So that would be nearer 30%.

No doubt there are other factors, but overall not a huge difference between electric or petrol/diesel, though my suspicion is that electric is actually less efficient if coming from fossil fuels.

I don't have a formula, remember all I initially said was:

Originally Posted by HPsauce

Greenness. This is largely down to the source of your electricity. Traditional power stations (coal, oil, gas) are no better and probably much worse at generating motive power per "CO2" than petrol/diesel. Once we get to a high level of renewables then the chain of energy delivery probably needs a rethink.

I think your formulae/calculations largely support my initial guess (highlighted in bold).

[Goran]

Originally Posted by HPsauce

I'd not include the 0.34 in the diesel calculation. So that would be nearer 30%.

No doubt there are other factors, but overall not a huge difference between electric or petrol/diesel, though my suspicion is that electric is actually less efficient if coming from fossil fuels.

I don't have a formula, remember all I initially said was:

I think your formulae/calculations largely support my initial guess (highlighted in bold).

I am happy to learn where I am going wrong. Refinery requires energy to run. It requires a lot of electricity. There are no IC engines for efficient crude oil combustion. Therefore you can't lose the power plant efficiency factor for IC engines.

Also 41% is unrealistically high for real world consumer diesel cars, I was too generous. And we didn't mix in petrol, what percentage of cars in the UK are petrol.

Of course if we said nuclear plant for electric cars then IC engines would lose out even more. There is just no way around that huge electric vehicle drive train efficiency factor of 68%.

[HPsauce]

Refineries are actually pretty efficient, as are many/most other processes in both chains.
The really BIG losses occur when hydrocarbons are burnt to generate power;
1. In power stations, typically running around 30% efficient
2. In vehicle engines, again around 30%

Electric vehicles (ignoring all the battery issues) will probably only become "better" in that competition when they can use power from alternative sources.