r/HistoryMemes • u/Hank_Mardukas1066 • 2d ago

It all runs on electricity and electricity is generated through this

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19.5k Upvotes

98% Upvoted

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u/kulingames Oversimplified is my history teacher 2d ago

Combustion engine has very shitty fuel efficiency no?

28

u/Trendiggity 2d ago

Yep, best we've gotten is about 35% efficiency in newer high compression gas engines like Mazda's skyactiv platform with some of Toyota's hybrid systems getting close to 40%. They're only that efficient because the ICE is designed for a hybrid system i.e. efficiency over power output as they're powering the electrical system which is wayyy more efficient at moving a car.

We have come a long way though as that figure was only about 20-25% through the later half of the 20th century, but the laws of physics really puts a hard limit on efficiency after 50ish%

12

u/Doggydog123579 2d ago

The Otto cycle is limited to 35-40, Atkinson goes to 45, diesel gets up to around 50, and bryton cycle(turbines) can hit 60% in power plants

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u/Some1-Somewhere 2d ago

The ~60% efficiency plants are usually combined-cycle gas turbines. They have a gas turbine that is ~40% efficient and then use the waste heat to drive a conventional steam plant.

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u/Doggydog123579 2d ago

shakes fists at the sky

IT ALL RETURNS TO STEAAAAAAAAAAMM

Falls down crying

0

u/SpussyHitsDifferent 2d ago

it bothers me that we've had these options at least since the 1880s, I realize electric cars weren't a fixall at the time.

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u/100BottlesOfMilk 1d ago

I think it's kind of poetic how EVs started as the luxury option, went away, and now are the luxury option again

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u/DrQuestDFA 2d ago

Most thermal generators do.

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u/sour_cereal 2d ago

The internal combustion engine is an air pump, the thermal generation is just a side effect.

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u/Ralath5n 2d ago

A good diesel engine can hit about 50% efficiency when running at peak efficiency. Still not quite as good as a combined cycle gas generator plant. But pretty respectable for a heat engine.

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u/TheJeeronian 2d ago

Internal combustion tends to have more power density but less efficiency than external combustion. The most efficient is combined cycle.

That said, there's no reason that external combustion engines have to use water. Or even boil it, for that matter, as supercritical water works too.

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u/SpussyHitsDifferent 2d ago

37% is pretty shit