5 ms·

Would this make sense in a Tesla Semi Truck? Cheaper lighter, electric motors are essentially the same as generators in reverse.

endymi0n 8y ago
This starts getting viable only now on a turbine scale of several Megawatts, with a very continuous workload. Scale this down to a car delivering an average of just a few kW that is driven maybe an hour or two per day and you‘ll lose all that efficiency to just cooling down the motor to -240•C and keeping it there.
- fyfy18 8y ago
  I assume that's why GP was talking about Tesla trucks. If a truck has two drivers it can be used for nearly a whole day - assuming the batteries could keep up.
  - MRD85 8y ago
    Who needs two drivers when the trucks are self driving and can operate safely 24 hours per day?
  - garyclarke27 8y ago
    Yes or even a Road Train with say 3 drivers on board for 24 hour use, big shortage of drivers in US apparantly. Road train must be more feasible now, software should be able to easily steer multiple trailers with independent steering ,forward in same path as cab and for reversing which would be tricky without such.
- ovi256 8y ago
  I get your point about the difference of scale in power but cars routinely reach 100 kW - that's just 134HP after all. Floor the gas pedal on a mid-size sedan or a small truck and there you have it, 100kW. Good point about the load cycle.
  - tigershark 8y ago
    The continuous output of a car is certainly not 100KW, unless you keep the first gear to travel at 60km/h literally drinking fuel...
    - gambiting 8y ago
      It will be for a truck though - once you have 40 tonnes on your trailer, I'm almost certain the engine will have to keep producing 100kW just to keep on moving at a steady 50mph.
    - TheSpiceIsLife 8y ago
      Even that won’t use max power. The amount of energy required to move a vehicle forward at 60km/h is a fixed quantity to do with rolling resistance and drag. There’s going to be greater loss due to friction in the engine and losses in the gearbox, probably in the single digit range? I honestly don’t know anything accurate. Most power is required accelerate.
tigershark 8y ago
In my opinion it doesn’t make sense at all even in this megawatt wind turbine as per my other comment.

endymi0n 8y ago

This starts getting viable only now on a turbine scale of several Megawatts, with a very continuous workload. Scale this down to a car delivering an average of just a few kW that is driven maybe an hour or two per day and you‘ll lose all that efficiency to just cooling down the motor to -240•C and keeping it there.

fyfy18 8y ago
I assume that's why GP was talking about Tesla trucks. If a truck has two drivers it can be used for nearly a whole day - assuming the batteries could keep up.
- MRD85 8y ago
  Who needs two drivers when the trucks are self driving and can operate safely 24 hours per day?
- garyclarke27 8y ago
  Yes or even a Road Train with say 3 drivers on board for 24 hour use, big shortage of drivers in US apparantly. Road train must be more feasible now, software should be able to easily steer multiple trailers with independent steering ,forward in same path as cab and for reversing which would be tricky without such.
ovi256 8y ago
I get your point about the difference of scale in power but cars routinely reach 100 kW - that's just 134HP after all. Floor the gas pedal on a mid-size sedan or a small truck and there you have it, 100kW. Good point about the load cycle.
- tigershark 8y ago
  The continuous output of a car is certainly not 100KW, unless you keep the first gear to travel at 60km/h literally drinking fuel...
  - gambiting 8y ago
    It will be for a truck though - once you have 40 tonnes on your trailer, I'm almost certain the engine will have to keep producing 100kW just to keep on moving at a steady 50mph.
  - TheSpiceIsLife 8y ago
    Even that won’t use max power. The amount of energy required to move a vehicle forward at 60km/h is a fixed quantity to do with rolling resistance and drag. There’s going to be greater loss due to friction in the engine and losses in the gearbox, probably in the single digit range? I honestly don’t know anything accurate. Most power is required accelerate.

tigershark 8y ago

In my opinion it doesn’t make sense at all even in this megawatt wind turbine as per my other comment.