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It would make infinitely more sense to look into carbon neutral hydrocarbon fuels that could be used in conventional turbofans. Some more material on this topi

It would make infinitely more sense to look into carbon neutral hydrocarbon fuels that could be used in conventional turbofans. Some more material on this topic: https://aviation.stackexchange.com/questions/26910/could-an-electric-engine-provide-the-same-performance-as-jet-engines-on-current https://aviation.stackexchange.com/questions/26910/could-an-...

ShorsHammer 9y ago
Another SE link of interest, how much electrical power needed to run a 747 engine: https://aviation.stackexchange.com/questions/19569/how-many-kilowatts-to-get-an-electric-747-8-airborne https://aviation.stackexchange.com/questions/19569/how-many-... The consensus is ~90 MW. That's a lot of energy, electric air travel is certainly possible, but it will likely come at a severe cost to speed and endurance. If we are going to travel slowly would personally prefer autonomous airships.
- TheSpiceIsLife 9y ago
  Megawatts is a power unit. To sustain 90MW for a 4hr flight you need a battery that can provide 360MWh of energy. Anyone care to do the numbers on how much a lithium ion battery would weigh to be able to deliver 360MWh, and remember if you want to use it more than once you can full charge no discharge it.
  - Hextinium 9y ago
    A standard lithium ion battery has between 100-265 Wh/kg if you need 360 thousand to 135 thousand kg of lithium ion batteries plus probably a few thousand for charging equipment. A a 747 has capacity for about 45k kg of fuel so a factor of 4 improvement is needed before that is comparable.
    - ShorsHammer 9y ago
      The energy density of most fossil fuels is still far beyond anything we've managed through incremental improvement on 1900's battery technology. There's much more work to be done.
- maccam94 9y ago
  I think we'll see smaller capacity VTOL aircraft for shorter flights before we get batteries with enough energy density for long-range flights. You'd just need to have a fast charging rate or potentially swappable batteries at landing pads. Daisy-chaining VTOL trips carrying 10-20 passengers ~100 miles at a time could be faster and more flexible. Uber has done some research on this too: https://www.uber.com/info/elevate/ https://www.uber.com/info/elevate/
- bewo001 9y ago
  When I last looked into this, I googled electric motors in the +30MW range and found that some gas pipelines use electric turbines of that power. These are massive, stationary engines which made me wonder if the weight of the motors might be an equally serious problem as the weight of the energy storage. Carbon neutral jet fuel really seems to be the simpler alternative.
greglindahl 9y ago
Is it impossible to develop 2 things at the same time? In fact, both are under development.

ShorsHammer 9y ago

Another SE link of interest, how much electrical power needed to run a 747 engine: https://aviation.stackexchange.com/questions/19569/how-many-kilowatts-to-get-an-electric-747-8-airborne https://aviation.stackexchange.com/questions/19569/how-many-... The consensus is ~90 MW. That's a lot of energy, electric air travel is certainly possible, but it will likely come at a severe cost to speed and endurance. If we are going to travel slowly would personally prefer autonomous airships.

TheSpiceIsLife 9y ago
Megawatts is a power unit. To sustain 90MW for a 4hr flight you need a battery that can provide 360MWh of energy. Anyone care to do the numbers on how much a lithium ion battery would weigh to be able to deliver 360MWh, and remember if you want to use it more than once you can full charge no discharge it.
- Hextinium 9y ago
  A standard lithium ion battery has between 100-265 Wh/kg if you need 360 thousand to 135 thousand kg of lithium ion batteries plus probably a few thousand for charging equipment. A a 747 has capacity for about 45k kg of fuel so a factor of 4 improvement is needed before that is comparable.
  - ShorsHammer 9y ago
    The energy density of most fossil fuels is still far beyond anything we've managed through incremental improvement on 1900's battery technology. There's much more work to be done.
maccam94 9y ago
I think we'll see smaller capacity VTOL aircraft for shorter flights before we get batteries with enough energy density for long-range flights. You'd just need to have a fast charging rate or potentially swappable batteries at landing pads. Daisy-chaining VTOL trips carrying 10-20 passengers ~100 miles at a time could be faster and more flexible. Uber has done some research on this too: https://www.uber.com/info/elevate/ https://www.uber.com/info/elevate/
bewo001 9y ago
When I last looked into this, I googled electric motors in the +30MW range and found that some gas pipelines use electric turbines of that power. These are massive, stationary engines which made me wonder if the weight of the motors might be an equally serious problem as the weight of the energy storage. Carbon neutral jet fuel really seems to be the simpler alternative.

greglindahl 9y ago

Is it impossible to develop 2 things at the same time? In fact, both are under development.