This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
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@MichaelPorter @yugthebug @Natasha_Jay so the common scale in the subtitle is wheels moving? Definitely a bit of a mind-twister! Possibly because the flow implies remaining.
@mikerspencer @yugthebug @Natasha_Jay Nor sure what you mean by “common scale in the subtitle.”
All of the numbers at the top of each diagram represent percentage losses from the original 100%. Let's say we start with 100 kWh.
Drivetrain losses are the same for both electric vehicles, 20% of whatever's left.
For the “UK grid" car, that's 20% of 45 kWh, or 9 kWh (9% of the original 100 kWh).
For the “wind & solar" car, it's 20% of 79 kWh, or 16 kWh (16% or the original 100 kWh). -
This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
Of the total energy a barrel of oil, a fraction can be converted into gasoline. Other fractions are converted into diesel and bunker fuel and lubricants and other industrial inputs etc
You can’t say 100% of oil going into a car. You have to start with the fraction of a barrel that that’s convertible into the fuel used in cars.
Even more fascinating is why a two legged meat puppet drags with them 1000 pounds of toxic waste to buy their milk.
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@Natasha_Jay
I am kinda wondering why the drivetrain is 16 percent loss vs 9 percent loss when they are both electric though??@yugthebug @Natasha_Jay A lot of power is lost in the gearbox vs electric cars that are (usually) direct drive.
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
@Natasha_Jay Also, oil is INCREDIBLY useful for making plastics, fertilizer, chemicals, synthetics, lubricants, and all sorts of other shit that's difficult to replace from natural sources. And then we just go and burn the shit...
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
Seems like should focus on developing chargers that allow DC-DC charging directly from on-site solar panels.
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
@Natasha_Jay Middle graphic is incorrect. You would not have losses for Gas supply & power station + Nuclear reactor heat + Biomass power + Other generation. You would only have one of them at a time!
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
@Natasha_Jay I call nonsense. The car isn’t determined by power source so why is a (for eg) Tesla powered by solar going to be getting more power to the wheels than “standard”electricity? Also why is transmission more expensive in one than the other? Is there some underlying assumption that solar is a home generated source? In which case it’s unlikely to fully power the car unless you have a very large array for a house.
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
@Natasha_Jay I've heard this described before as "the primary energy fallacy"
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@mikerspencer @yugthebug @Natasha_Jay Nor sure what you mean by “common scale in the subtitle.”
All of the numbers at the top of each diagram represent percentage losses from the original 100%. Let's say we start with 100 kWh.
Drivetrain losses are the same for both electric vehicles, 20% of whatever's left.
For the “UK grid" car, that's 20% of 45 kWh, or 9 kWh (9% of the original 100 kWh).
For the “wind & solar" car, it's 20% of 79 kWh, or 16 kWh (16% or the original 100 kWh).@MichaelPorter
The subtitle reads "energy flows... on a common scale."I understand the maths and you're explaining it well - thanks! But the figure is still a little confusing that one scenario gets 11% braking returns and the other 19%. Might just have been better to leave that bit off.
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
@Natasha_Jay I think this would work a little better if it included the amount of energy. I get what it’s trying to say, that electric vehicles on an electrified grid are the most efficient of the three options here, but I think people could get thrown off by seeing different percentages between the two electric vehicles. Percentages can be tough, but everyone understands loss, and you can compare the total energy expenditure versus kinetic movement at the end.
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@Natasha_Jay the dodges there are that it doesn't show a hybrid on petrol and that none of the cars seem to have passenger cabin heating, but it's essentially true.
Now if only there were more battery cars that weren't spyware-on-wheels...
@mjr @Natasha_Jay if you posted this on a mobile device the car spyware is redundant anyway.
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
@Natasha_Jay as one xkcd says, electric and gas engines both have pros and cons
on the one hand, electric motors are cleaner and more efficient
on the other hand, electric motors are more powerful -
@mjr @Natasha_Jay if you posted this on a mobile device the car spyware is redundant anyway.
@mscheffel @Natasha_Jay no mobile device is with me every car trip, I have the source code to most of my mobile devices & that seems not possible with most cars yet, and I hate the "one thing is broken so we shouldn't care if everything else is broken too" idea.
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
@Natasha_Jay by right, there should be a 20% for solar, and whatever is lossed for wind. but i get why those numbers aren't included.
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
@Natasha_Jay For wind power it ignores how much wind energy the turbine fails to capture. For solar it ignores how much the panels fail to convert to electricity. In what way is this a fair comparison?
For petrol it fails to account for what could have been gained by separating out the hydrogen atoms and fusing them... but I'll let that one slide for now.
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
@Natasha_Jay FWIW, I'm not sure this is a particularly enlightening way to think or describe this issue. Using the abstract amount of theoretically available maximal energy is intuitive in only fairly rare and narrow circumstances, and this framing feels weird to me.
Maybe, describing the inherent conversion efficiency limits from fuel to motion vs electricity to motion would work better? The foundational ratio is still the same, but at least, it'd be close to the abstractions that physicists and engineers actually use in thinking about motor/engine efficiency.
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It should be noted that the huge drop in petrol cars' efficiency when it reaches the engine and dissipates into heat is NOT going to be improved much upon. There is a fundamental physics limit that prevents it.
@mespique @Natasha_Jay je zajímavé, že u jaderných (atomových) elektráren, se nad tím nikdo nepozastaví...
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This analysis is fascinating: it breaks down how when you fill up a petrol car most of the energy never moves it.
Petrol car: 13–21% of the crude oil's energy reaches wheels.
Electric car on today's UK grid: 43–45%.
Electric car on wind+solar: 77–80%.
via Jan Rosenow, Professor of Energy & Climate Policy at University of Oxford
@Natasha_Jay he's on Fedi: @janrosenow
unfortunately not active anymore, but used to post a lot. Maybe give him a follow to summon him back
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@Natasha_Jay Also, oil is INCREDIBLY useful for making plastics, fertilizer, chemicals, synthetics, lubricants, and all sorts of other shit that's difficult to replace from natural sources. And then we just go and burn the shit...
I used to maintain a biodiesel plant. Soybeans in, oil products out. Byproducts were USP grade glycerin, lecithin, etc... And it was done at an incredibly massive scale, efficiently.
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@MichaelPorter
The subtitle reads "energy flows... on a common scale."I understand the maths and you're explaining it well - thanks! But the figure is still a little confusing that one scenario gets 11% braking returns and the other 19%. Might just have been better to leave that bit off.
@mikerspencer @yugthebug @Natasha_Jay Derp, I didn’t even read that. Okay, I see what you’re getting at.
btw The issue we are discussing came up *repeatedly* when I was teaching science - mainly when a lab result was a percentage, *and* the students had to express uncertainty, which often was a percentage also. So we had to be very clear as to whether a result was
(25 ± 4)% or 25% ± 4% (i.e. (25 ± 1)%).
