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There are electric planes out there, but they're pretty small. You're not likely going to see any electric 747s anytime soon, if ever. "A battery's efficiency,

There are electric planes out there, but they're pretty small. You're not likely going to see any electric 747s anytime soon, if ever. "A battery's efficiency, or ability to hold power, is measured in specific energy. Right now, even the best batteries have a specific energy of only 250 watt-hours per kilogram, but we have to get closer to 800 to really start flying, and that is still nothing compared to jet fuel's specific energy, which is nearly 12,000 watt-hours per kilogram." "So if you want to add more power to a plane, you need to get a bigger battery, and to get that plane airborne despite the weight, you'll need even bigger battery that's more powerful, but that means more weight. And then you'll need an even bigger battery to offset that weight." https://www.businessinsider.com/electric-planes-future-of-aviation-problems-regulations-2020-3 https://www.businessinsider.com/electric-planes-future-of-av...

gambiting 5y ago
Not with Lithium-Ion tech, no. But aluminum-air batteries provide an order of magnitude higher densities of energy(~1300Wh/kg), and should be able to power a large-ish plane. The main problem being of course that aluminum air batteries are not rechargable, but all you'd need to do is swap the spent aluminium rods at the airport and replace them with fresh ones - then use renewable energy nearby to melt and reform the aluminium rods to be used again. https://en.wikipedia.org/wiki/Aluminium%E2%80%93air_battery https://en.wikipedia.org/wiki/Aluminium%E2%80%93air_battery
- cableshaft 5y ago
  Interesting. I'm surprised I didn't hear that solution mentioned in Bill Gates "How to Avoid a Climate Disaster" book. He basically made the same battery weight argument and was pushing for alternative biofuels for planes, if I remember correctly. And that was just published earlier this year, and seemed pretty comprehensive about discussing all possible solutions, at least as far as I could tell. Maybe just because it's (presumably) nowhere near the point where it could be feasible for commercial passenger planes?

gambiting 5y ago

Not with Lithium-Ion tech, no. But aluminum-air batteries provide an order of magnitude higher densities of energy(~1300Wh/kg), and should be able to power a large-ish plane. The main problem being of course that aluminum air batteries are not rechargable, but all you'd need to do is swap the spent aluminium rods at the airport and replace them with fresh ones - then use renewable energy nearby to melt and reform the aluminium rods to be used again. https://en.wikipedia.org/wiki/Aluminium%E2%80%93air_battery https://en.wikipedia.org/wiki/Aluminium%E2%80%93air_battery

cableshaft 5y ago
Interesting. I'm surprised I didn't hear that solution mentioned in Bill Gates "How to Avoid a Climate Disaster" book. He basically made the same battery weight argument and was pushing for alternative biofuels for planes, if I remember correctly. And that was just published earlier this year, and seemed pretty comprehensive about discussing all possible solutions, at least as far as I could tell. Maybe just because it's (presumably) nowhere near the point where it could be feasible for commercial passenger planes?