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Are there denser ways to store electrical energy? Hydrogen fuel cells maybe? Seems like you need something much lighter than lithium-ion batteries to even begi

by TillE 9y ago

Are there denser ways to store electrical energy? Hydrogen fuel cells maybe? Seems like you need something much lighter than lithium-ion batteries to even begin to fill the role of passenger planes.

speeq 9y ago
Here are some comments from Musk regarding electric aircraft: https://www.youtube.com/watch?v=yx3auTD85Fw https://www.youtube.com/watch?v=yx3auTD85Fw
- ratsbane 9y ago
  "I'd love to do it... but I think my mind would explode."
kevincox 9y ago
Hydrogen fuel cells would also make refuelling much faster. In the video they claimed an hour recharge time for the small plane. While you can get more parallelism as you add more batteries it still seems like making it much faster would be beneficial.
- Hasz 9y ago
  It seems like battery swapping would be a viable alternative here. The packs are only ~17kWh
- labcomputer 9y ago
  Probably not as much as you'd think, though. Cars powered by compressed natural gas take longer to fill than gasoline-powered ones[1]. I can't find it right now, but Edmunds did a long-term test of a natural gas Honda Civic. One of the persistent complaints was long fill times at public high-pressure stations. Natural gas has about 4x the energy density of Hydrogen, so the problem becomes even worse.
  - seanmcdirmid 9y ago
    Ya, that explains the huge lineups to fill up natural gas vehicles in Thailand. They have plenty of gas, but the infrastructure needed to distribute it is tricky.
- dogma1138 9y ago
  Hydrogen fuel cells would solve another problem and that is when you expand the hydrogen you reduce the weight of the aircraft. The problem with batteries is that a full battery and a discharged one weigh the same.
Hasz 9y ago
The tricky part with hydrogen is the containment. You either need cryogenically cooled tanks to get it to a liquid state, or metal hydrides to store it chemically. Both have fairly poor energy density (by volume and mass). What's more, the fuels cells aren't cheap either, and some of the more efficient ones operate at very high temperatures. For all it's faults hydrocarbon fuels are really good at storing energy that's easily extractable.
evjim 9y ago
Hydrogen creation using electrolysis is really inefficient. Somewhere under 50%.

by TillE 9y ago

Are there denser ways to store electrical energy? Hydrogen fuel cells maybe? Seems like you need something much lighter than lithium-ion batteries to even begin to fill the role of passenger planes.

speeq 9y ago

Here are some comments from Musk regarding electric aircraft: https://www.youtube.com/watch?v=yx3auTD85Fw https://www.youtube.com/watch?v=yx3auTD85Fw

ratsbane 9y ago
"I'd love to do it... but I think my mind would explode."

kevincox 9y ago

Hydrogen fuel cells would also make refuelling much faster. In the video they claimed an hour recharge time for the small plane. While you can get more parallelism as you add more batteries it still seems like making it much faster would be beneficial.

Hasz 9y ago
It seems like battery swapping would be a viable alternative here. The packs are only ~17kWh
labcomputer 9y ago
Probably not as much as you'd think, though. Cars powered by compressed natural gas take longer to fill than gasoline-powered ones[1]. I can't find it right now, but Edmunds did a long-term test of a natural gas Honda Civic. One of the persistent complaints was long fill times at public high-pressure stations. Natural gas has about 4x the energy density of Hydrogen, so the problem becomes even worse.
- seanmcdirmid 9y ago
  Ya, that explains the huge lineups to fill up natural gas vehicles in Thailand. They have plenty of gas, but the infrastructure needed to distribute it is tricky.
dogma1138 9y ago
Hydrogen fuel cells would solve another problem and that is when you expand the hydrogen you reduce the weight of the aircraft. The problem with batteries is that a full battery and a discharged one weigh the same.

Hasz 9y ago

The tricky part with hydrogen is the containment. You either need cryogenically cooled tanks to get it to a liquid state, or metal hydrides to store it chemically. Both have fairly poor energy density (by volume and mass). What's more, the fuels cells aren't cheap either, and some of the more efficient ones operate at very high temperatures. For all it's faults hydrocarbon fuels are really good at storing energy that's easily extractable.

evjim 9y ago

Hydrogen creation using electrolysis is really inefficient. Somewhere under 50%.