91–100 of 919 posts
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You may not have a choice in the matter as more and more countries are thinking of/implementing ICE bans in the near future.
They're unlikely to succeed because if the massive tax on poor people (ICE bans) actually gets implemented, all of the poor people who are forced to buy an unaffordable EV will vote for populists promising to unwind the bans.
Why does 500wh/kg make electric aircraft possible? 6x less than kerosene. Is that the break even on cost if you can source very cheap electricity? Seems like it would still annihilate the payload/range.
Well we had electric aircraft for half a century, but thats just toys. The variable is how many passengers can you fit.
This is simply not true with electrical planes. A mega watt hour of power is about 60-100$. And much cheaper than that with renewables. Not at retail prices of course. But if you consume power by the mwh, you'd be investing in your own generation (solar + storage) pretty soon. A mwh is about what you need to move a small electrical plane a few hundred miles. The kerosene cost for a similar journey in a small jet is going to be hundreds of dollars, even for a small jet. The smallest jets burn 50-100 gallons of fuel per hour (in cruise). Depending where you get your fuel, that ranges from 3-5$ per gallon. That's why small jets are only for rich people. Even a very short flight sets you back hundreds of dollars. A simple propeller plane is cheaper. But we're still talking 5-10 gallons per hour. That's why people talk about 100$ hamburgers. Because that's what it costs to take your tiny plane out to grab a burger somewhere.
Big big jets are a bit more economical with fuel than small ones. But they only makes sense if you can distribute fuel cost among many passengers.
With electrical, you can use lots of smaller planes cost effectively rather than having to put lots of people in a few bigger ones. For the same reason, you don't need big airports either. Or worry about pollution. And even the noise of small electrical planes is not as much of a problem. And with autonomous flight, we won't even need pilots long term. Small electrical planes are good enough and much nicer for passengers, more flexible to operate, etc.
It's not a new battery chemistry, though. It's still lithium-ion. Does something prevent thermal runaway with this?
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Let's consider Cessna-172S ([4]). Its characteristics: - 130 kW engine, Lycoming_O-360 that weighs 117 kg. For comparison, an electric motor of this range would weigh 11-13 kg (at 10-12 kW/kg, [2]). That saves 100+ kg weight immediately and we can put 50+ kWh batteries instead. - It carries up to 200 liters of kerosene ([3]), which weighs 164 kg. We can place 82 kWh of batteries instead. - The engine consumes around…
The power requirement at cruising speed would quite a lot less than max power would it not? If cruse consumed 60% of max you'd be using closer to 80kW which would give you over 2 hours flight time.
Why does 500wh/kg make electric aircraft possible? 6x less than kerosene. Is that the break even on cost if you can source very cheap electricity? Seems like it would still annihilate the payload/range.
Seems like marketing hype to me. An 8-hour transatlantic flight requires something like 600MWhr of energy. That's about 75MW, which is in small nuclear reactor territory.
(They actually planned to go all the way to 350MW, which could theoretically run a transatlantic passenger jet with 2,000 passengers, assuming it’s even possible to build such an airframe.)
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My plan to buy an EV in the next five years may be realistic after all. Happy!
You may not have a choice in the matter as more and more countries are thinking of/implementing ICE bans in the near future.
Why does 500wh/kg make electric aircraft possible? 6x less than kerosene. Is that the break even on cost if you can source very cheap electricity? Seems like it would still annihilate the payload/range.
Let's consider Cessna-172S ([4]). Its characteristics: - 130 kW engine, Lycoming_O-360 that weighs 117 kg. For comparison, an electric motor of this range would weigh 11-13 kg (at 10-12 kW/kg, [2]). That saves 100+ kg weight immediately and we can put 50+ kWh batteries instead. - It carries up to 200 liters of kerosene ([3]), which weighs 164 kg. We can place 82 kWh of batteries instead. - The engine consumes around…
Earlier quoted context omitted.
You may not have a choice in the matter as more and more countries are thinking of/implementing ICE bans in the near future.
Not banning per se, just stopping sales of new. So there will still be plenty of used ICE cars knocking around for a good few years.
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I feel that synthetic kerosene via electrolysis is a far more viable path to sustainable aviation than battery-electric engines. The energy-inefficiency doesn’t really matter as long as you can keep the total cost of the flight within consumer reach.
Carbon neutral synthetic fuels might make sense for airliners, because they're already pretty efficient, reliable and incomprehensibly powerful and there's tons of other stuff in them that'd require maintenance even if you took out the engines. They don't make sense for general aviation planes that are usually a fifty year-old engine design that requires expensive overhauls and guzzles expensive fuel wrapped in a bit…
Earlier quoted context omitted.
You may not have a choice in the matter as more and more countries are thinking of/implementing ICE bans in the near future.
We do have a choice because, on paper, we do have a choice in choosing those countries’ politicians. I know I’ll never give my vote to a politician keen on banning gasoline cars. It’s sadly also true that the technocrats actually taking those decisions are a lot less directly accountable, but nothing that a second “yellow vests” movement won’t be able to fix.