4 ms·

61.5% sounds like a lot, but how much electricity is needed to replace everything that fossil fuel is now used for? I think it needs to increase to 400% or so t

61.5% sounds like a lot, but how much electricity is needed to replace everything that fossil fuel is now used for? I think it needs to increase to 400% or so to do that.

ViewTrick1002 2y ago
We don't need to replace primary energy with electric energy in a 1:1 ratio. An ICE car is 20-30% efficient, an EV is 90% efficient. Generally we are looking at a grid expansion, but it is not massive. See this amazing chart on rejected vs. useful energy: https://flowcharts.llnl.gov/ https://flowcharts.llnl.gov/
- WalterBright 2y ago
  > an EV is 90% efficient An EV is 85-90% efficient with power coming out of the batteries. However, the charging efficiency of the batteries is at about 80%. So the overall efficiency is 80% of 90%, or 72%.
  - heavenlyblue 2y ago
    For the sake of replacement, we should not include the charging efficiency, because the context is that of "how kuch energy the car can store" rather than "where it comes from"
    - Scarblac 2y ago
      It's "how much is needed to keep doing the same thing", I don't see why charging would be excluded.
    - WalterBright 2y ago
      It is not about how much it can store. You cannot wish away the charging losses. There are no losses to pumping gas into a tank. Nor can you wish away the losses in the charger itself. Converting AC to DC is hardly 100% efficient.
      - pfdietz 2y ago
        In that case, you should also not wish away refining losses, where petroleum is turned into gasoline and other fuels.
        WalterBright 2y ago
        If you want to get an accurate accounting of CO2 emissions, sure.
_ph_ 2y ago
Somewhere between 2-3x the electricity consumed right now (which is way down from the peak several years ago as efficiency increases, e.g. LEDs instead of light bulbs etc.). It would be crazy expensive to build nuclear reactors to produce so much electricity, with renewables it is still quite a task, but a much more manageable one.
- Moldoteck 2y ago
  in fact for germany building a similar renewable output will be much more expensive. Don't forget about transmission and balancing. Needless to say Germany doesn't have an actual plan to ditch gas, even h2-ready plants will either use a mix with gas(most probably) or pure h2(if it'll even be deployed) will still have huge NOx emissions

61.5% sounds like a lot, but how much electricity is needed to replace everything that fossil fuel is now used for? I think it needs to increase to 400% or so to do that.

ViewTrick1002 2y ago

We don't need to replace primary energy with electric energy in a 1:1 ratio. An ICE car is 20-30% efficient, an EV is 90% efficient. Generally we are looking at a grid expansion, but it is not massive. See this amazing chart on rejected vs. useful energy: https://flowcharts.llnl.gov/ https://flowcharts.llnl.gov/

WalterBright 2y ago
> an EV is 90% efficient An EV is 85-90% efficient with power coming out of the batteries. However, the charging efficiency of the batteries is at about 80%. So the overall efficiency is 80% of 90%, or 72%.
- heavenlyblue 2y ago
  For the sake of replacement, we should not include the charging efficiency, because the context is that of "how kuch energy the car can store" rather than "where it comes from"
  - Scarblac 2y ago
    It's "how much is needed to keep doing the same thing", I don't see why charging would be excluded.
  - WalterBright 2y ago
    It is not about how much it can store. You cannot wish away the charging losses. There are no losses to pumping gas into a tank. Nor can you wish away the losses in the charger itself. Converting AC to DC is hardly 100% efficient.
    - pfdietz 2y ago
      In that case, you should also not wish away refining losses, where petroleum is turned into gasoline and other fuels.
      - WalterBright 2y ago
        If you want to get an accurate accounting of CO2 emissions, sure.

_ph_ 2y ago

Somewhere between 2-3x the electricity consumed right now (which is way down from the peak several years ago as efficiency increases, e.g. LEDs instead of light bulbs etc.). It would be crazy expensive to build nuclear reactors to produce so much electricity, with renewables it is still quite a task, but a much more manageable one.

Moldoteck 2y ago
in fact for germany building a similar renewable output will be much more expensive. Don't forget about transmission and balancing. Needless to say Germany doesn't have an actual plan to ditch gas, even h2-ready plants will either use a mix with gas(most probably) or pure h2(if it'll even be deployed) will still have huge NOx emissions