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Most electrical planes flying today will have around 160-200 wh/kg of battery. That's not a lot but somebody is buying them nonetheless. The reason for that rel
by jillesvangurp 5y ago
Most electrical planes flying today will have around 160-200 wh/kg of battery. That's not a lot but somebody is buying them nonetheless. The reason for that relatively modest energy density is that anything flying and certified now would have entered the certification process many years ago. The question is not if those batteries can be improved but by how much.
Tesla already has cars on the road with batteries doing better than that. Their upcoming 4680 battery cells will be around 380 wh/kg, apparently. Then there are several companies working on solid state batteries promising closer to 500-600 wh/kg. Sounds good? That's 2-3 x the range of electrical planes on the market now or very soon. There's nothing to be skeptical about here. Pretty much a done deal. With that type of battery, we'll be seeing planes do 400-800miles; possibly a bit more. If you think that's ludicrous, the Eviation Alice is currently pre-selling a plane that will do 440 miles. Apparently, they use 260 Wh/kg batteries currently. Upgrading to something with 500 wh/kg would pretty much get them close to a 1000 mile range.
I consider 2x to be the minimum of what we can expect this decade. That's just a matter of updating these planes with batteries that are either already being produced or will be very soon. More a matter of when than if, really. These are first generation planes too. It's not a question of if they will improve but how quickly and by how much. Designs, engines, wiring, materials, etc. There still is a lot of room for improvements.
Longer term, I'd say 4-6x current ranges should almost certainly be doable based on just battery improvements. My view: 4x would be disappointing. 6x is a good number to shoot for longer term and we can actually hope for more. Like 8-10x. But actually 3x current ranges would already be a game changer. We'll see.
- SECProto 5y agoYes, this feels a bit like reading an opinion piece dissing on EVs in CarAndDriver 15-20 years ago. Of which there were many.
- bernulli 5y agoRange is one thing - what is the passenger capacity of these planes?
- jillesvangurp 5y agoWrong metric. Cost per passenger per mile is a better one. The reason big jets are popular is that jets burn lots of fuel, which is expensive. Bigger jets burn fuel a bit more efficiently so the cost per passenger becomes more reasonable. Big battery electric planes are likely not possible with current battery technology. But the good news is that small electrical planes are pretty cheap and the electricity is cheap too. So, instead of buying a big Boeing to save fuel, you could buy a few dozen smaller planes, fly to smaller airports that Boeing would not even be allowed to land, and drop passengers off closer to their destinations.
- bernulli 5y agoIn addition to calling my question 'wrong' - can you also answer it? Also, if your 'correct' metric were right, then everyone would walk. Does that solve the problems flying does? I don't think so. [edit]: Also, I guess your metric explains why everyone is only taking the bus or train, and private transportation does not exist?
- blip54321 5y agoI'll answer a different question. The major cost of airplanes is engine wear. Engines have a TBO of maybe 2000 hours, which means about a year's worth of flying at 40 hours per week. For a cheap plane like a basic Cessna, the overhaul is the cost of the aircraft. If electric planes are lower-maintenance, for GA purposes, they could be a lot cheaper. The hobby would go from millionaires to ordinary folks. Electric motors don't wear out like combustion ones do.
- bernulli 5y agoSure, and an engine that wouldn't need any fuel/power at all would be even better - the question is, what is practically/theoretically achievable. But I guess the fact that everyone is avoiding the elementary question of 'how much can a transportation system transport' tells me all I need to know about the practicality here.
- mike_d 5y agoThe Air Force has proven a system that uses renewable energy to power a system that combines water and carbon dioxide extracted from the air to produce E-Jet synthetic fuel. Currently a chemically similar but less environmentally sound synthetic fuel is approved to be mixed 50/50 with regular JP8 in military aircraft and they are doing acceptance testing for full synthetic. This effectively takes every high efficiency jet engine and makes it carbon neutral, with the added benefit that you don't need to ship the fuel anymore. At that point electric planes are dead. https://www.afmc.af.mil/News/Article-Display/Article/2820003/air-force-partners-with-twelve-proves-its-possible-to-make-jet-fuel-out-of-thin/ https://www.afmc.af.mil/News/Article-Display/Article/2820003...
- jillesvangurp 5y agoThat's one of several possible fuels. What all of those have in common is that they are more expensive than kerosine, which in turn is more expensive than electric. The big advantage of battery electric is cost. Wherever you can fly them, it will be the cheapest way to do it, by far.
- ncmncm 5y agoCosts change. Cost of synfuels will only come down, as solar electric continues to do.
- genewitch 5y agoHow do you get the CO2 out of the air, other than the obvious "grow corn"?
- ncmncm 5y agoSeriously? Adsorb it. You have to move a lot of air through your system, but that just costs energy. With solar cost still in free fall, it will soon be cheaper to get CO2 out of the air, add hydrogen extracted from water, and deliver CH4 or larger molecules, than to get them out of the ground.
- AtlasBarfed 5y agoHow about this for phase-out: 1) use ev motor engines, but power with a fuel cell + methane/hydrocarbons 2) phase in synthetic fuels 3) swap out the fuel cell and synth fuel for batteries when feasible