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I think your math is faulty. An electric plane wouldn't need as much energy as a fuel burning jet because you only need to be turning the fan blades. Where a j

I think your math is faulty. An electric plane wouldn't need as much energy as a fuel burning jet because you only need to be turning the fan blades. Where a jet loses a lot of energy compressing the air, a electric jet would probably be more like a propfan or a ducted fan. The best jets are about ~35% efficient at turning energy in to forward speed. Assuming an electric motor is 80% efficient and the propulsion is 80% efficient, you'd be looking at 64% efficiency. It's possible there are other factors reducing the efficiency of an electric motor, but I doubt they are worse than parity with the existing jets. Using your numbers, that means an electric plane would use $25,000 worth of electricity. The typical plant outputs much more than 333 MW as well. As we move toward less fossil fuel use, infrastructure will better support our increased energy usage. When internal combustion engines were first introduced, someone easily could have said "Do you realize how many billions of gallons of fuel it will take to power all of that? Not a chance in the world of that happening!" The state I live in has well over 100,000 MW of generating capacity. Given that scale, supplying energy to planes doesn't seem so ridiculous. I'm willing to bet that we won't just be slapping electric motors in place of fuel turbines anyways. Plane designs will probably progressively move towards better suitability for alternative energy. Maybe electronic motors for extra energy during take-off, with enough reserve power for emergencies?

ars 10y ago
> Where a jet loses a lot of energy compressing the air It does not loose energy from this. The compressed air expands afterward, returning almost all the energy. > The best jets are about ~35% efficient at turning energy in to forward speed. Where are you getting these numbers? I'm seeing much much higher numbers than that then I google it. > Assuming an electric motor is 80% efficient and the propulsion is 80% efficient, you'd be looking at 64% efficiency. Again, those numbers don't sound in the slightest bit correct. > Using your numbers, that means an electric plane would use $25,000 worth of electricity. What? Run your numbers again. I assumed 50% efficiency for Jets and 100% for electrical. > The state I live in has well over 100,000 MW of generating capacity. Given that scale, supplying energy to planes doesn't seem so ridiculous. It's not about the energy usage, it's about how do you connect the thing to an airplane. Do you plan to move cables the size of telephone poles? 100,000 volts? Have you seen electrical substations? Does that look like the kind of thing you would put on an airplane?
- msandford 10y ago
  On electric you have transmission losses, charge losses, discharge losses, losses in the motor controller and losses in the motors. Most batteries aren't better than about 80% charging and about the same discharging. So 0.8 to the fourth, or about 40%

ars 10y ago

> Where a jet loses a lot of energy compressing the air It does not loose energy from this. The compressed air expands afterward, returning almost all the energy. > The best jets are about ~35% efficient at turning energy in to forward speed. Where are you getting these numbers? I'm seeing much much higher numbers than that then I google it. > Assuming an electric motor is 80% efficient and the propulsion is 80% efficient, you'd be looking at 64% efficiency. Again, those numbers don't sound in the slightest bit correct. > Using your numbers, that means an electric plane would use $25,000 worth of electricity. What? Run your numbers again. I assumed 50% efficiency for Jets and 100% for electrical. > The state I live in has well over 100,000 MW of generating capacity. Given that scale, supplying energy to planes doesn't seem so ridiculous. It's not about the energy usage, it's about how do you connect the thing to an airplane. Do you plan to move cables the size of telephone poles? 100,000 volts? Have you seen electrical substations? Does that look like the kind of thing you would put on an airplane?

msandford 10y ago
On electric you have transmission losses, charge losses, discharge losses, losses in the motor controller and losses in the motors. Most batteries aren't better than about 80% charging and about the same discharging. So 0.8 to the fourth, or about 40%