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does anyone know the viability of hydrogen fuel cell electric motor airplanes? It seems like this is a more logical step, since from what I've read the energy
by awongh 9y ago
does anyone know the viability of hydrogen fuel cell electric motor airplanes? It seems like this is a more logical step, since from what I've read the energy density of batteries really isn't optimal for something like an airplane, even with technologies projected to come to market in the next couple of decades. And the whole thing still has the possibility of being zero-emissions.
- worldsayshi 9y agoAlso, perhaps it doesn't have to travel as far as conventional airplanes. Perhaps it can be okay to be twice as slow (because of more stops and lower powered engines) if it's only slightly cheaper. Trains and long distance busses are still around for routes that are also trafficked by airplanes. Presumably because they are often cheaper.
- awongh 9y agoI guess I was more extrapolating to jet engines, where I don't know if speed is as much of a factor in energy conservation, given the market.
- audunw 9y ago> And the whole thing still has the possibility of being zero-emissions. Well, so does a hybrid plane, if it's fueled with biofuels. Zero net CO2 emissions anyway. I would imagine other emissions are less problematic since it happens far away from populated areas. I'm not sure why hydrogen is desirable. Hydrocarbons have higher energy density and is easier to store and fuel. I can imagine that the closed loop of H2O + electricity <-> electricity + H2 + O is more efficient than the hydrocarbon equivalent. But neither technology is near their theoretical limits, so it's a bit hard to say yet. Regardless, if we build hybrid planes, we can use whatever technology makes the most sense. It shouldn't be too hard to swap out the energy storage mechanism. Who knows, maybe we'll invent a good rechargeable aluminum-air battery and replace everything with that.
- Tarrosion 9y agoIt's worth noting that burning jet fuel at airliner flight altitudes is roughly 2x as bad for the climate as the carbon emissions alone would suggest: http://www.ipcc.ch/ipccreports/sres/aviation/index.php?idp=64 http://www.ipcc.ch/ipccreports/sres/aviation/index.php?idp=6...
- awongh 9y agowhy does bio-fuel mean net zero emissions? I assume you're talking about bio-disel or ethanol? Don't both of these still produce cO2 when you burn them? But if you're producing the hydrogen with zero emissions, then it's a 100% cO2 free process, isn't it?
- eru 9y agoWhen a tree makes wood, it takes CO2 out of the atmosphere. When you burn the wood, you release exactly that carbon. Similar for making ethanol.
- eru 9y agoHydrogen storage ain't easy. It's not the motors that are the problem in weight, but hydrogen storage tanks or electric batteries.