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this post was submitted on 15 Aug 2026
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This seemed intuitively wrong to me (like, way too low a cost), but: 25,000 pounds moving 100 mph is equal to 11,331,007 J of kinetic energy. Since 3.6 million J equals 1 kWh and 1 kWh on average costs $0.17, that means you could accelerate 25,000 pounds to reasonable bare minimum flying speed for about fifty cents (not considering efficiency of the machinery). My mind still can't process this, but math is math.
On the other hand, looking at it from a potential energy perspective it's a bit more expensive. 25,000 pounds at a cruising altitude of 10,000 ft. (still quite low from an airliner perspective) is about 339 million J, 94 kWh or about $16 -- the cost of lunch at MacDonald's.
Since a plane requires the most thrust at takeoff, you could use ground-based catapults to get the plane to takeoff speed (or faster even) and then you could carry smaller batteries and propelling machinery. For extra fun, you could have landing planes snag a wire and use their momentum to accelerate a plane taking off.
To save even more weight, since you're going airport-to-airport you could leave off the landing gear and just have the planes come down on a bouncy trampoline-like surface. If you think that's batshit crazy, the British actually experimented with this idea for their aircraft carriers in the 1950s.
Edit: to make these numbers more realistic I'm going to assume something like a 737, which can weigh something like 150,000 pounds fully loaded (this includes fuel but you'd need batteries instead for an electric plane). Getting this to a 150 mph takeoff speed would take about 100 million J (getting it then to a cruising speed of 500 mph would be another 233 million J, but that's pretty minor compared to the other costs). Climbing this plane to 30,000 ft would take 6.1 billion J. Resisting a drag force of 5000 pounds (about what a 737 experiences at cruising speed at 30,000 ft) for 500 miles (the distance from Cleveland to New York City) would need 17.6 billion J. Assuming landing is free (fuck TANSTAAFL) that means a typical trip needs 23.8 billion J or 6618 kWh or $1125. Assuming a real-world efficiency of 25% means the actual cost would be $4500 (which is in the ballpark of what jet fuel costs). Assuming 200 passengers, that's $22.50 per person. Not exactly "$5 of electricity" but surprisingly small.
Feel free to check my math, my brain hurts.
Don't you dare talk about catapulting using electric technologies in America though. Steam only! πΊπΈπ½π¦ π
I didn't say which type of catapult. I don't need ICE showing up at my door.
Steam melts ice! Also many wavelengths of lasers does too if you want to be modern
Gabe Newell made billions with steam! You're all stupid!
There are many who have suggested replacing the fuel intensive takeoff with electric ramps, similar to what the do on aircraft carriers. The problem is most people could not handle 3-4 gs.
But, there could be a detachable battery pack that disconnects after takeoff to fly back to charge as a drone.
I fucking hate everyone and would love to subject you fucks to 4g of pain taking off with a stupid catapult system. Nice math.
The Navy is stupid.
All those screaming kids would get a quick education on how relatively nice everything was before the plane was launched.
"Billy, why are you crying? Do I have to take you on another plane ride? Oh, you're gonna cry harder now? That's it, I'm getting the vomit bags. I got this nice new child design one for you that wraps around your head and ties closed at your neck. Won't that be a treat?"
One important caveat to this. It costs less than 17 cents to generate 1 kwh. Closer to 3 cents really. But that's the cost of making the electricity, getting that electricity to a house or charger or what have you costs more. Since energy is a for profit industry they tack all the logistics costs to the client buying the electricity.
So your math is spot on but I fear the amount of markup on the electricity will be massive especially since it's for a business let alone an airline.
National average it's 55Β’ to run 3kw on 3phase electricity for an hour. Offshore areas like Hawaii and Alaska see higher costs like 1.60$/hr per 3kw on 3phase electricity but Alaska has a higher natural gas usage and Hawaii is further away from the CONUS electrical grid. National average per 24/hrs of charging is a little over 13$ with 3kw at 3phase.
And yet it still costs me 30 dollars to charge my car in Georgia and in a state like new York it's 60 to 100 dollars.
The entire airport is now covered in solar panels. Yes, the runway is a solar panel too.
Solar Freakinβ Runways!
Ahhh. That makes sense. I'm assuming the airplane is also just a giant flying solar panel!
Correct. You are a solar panel now too. Bon voyage!
A plane should still be capable of unassisted taking off and landing for emergencies, imo.
Landing yes, it's kinda silly to try to implement arresting cables for landing anyway. Takeoff though? If the system is broken, well then takeoff is delayed, but that wouldn't be an emergency. Planes can't take off all the time because of weather conditions.
And they lose spots at terminals.
Yeah same thing that happens because of weather conditions. Not an emergency.
yeah it's pretty crazy how much energy is in fuel.
1 kg of oil contains about 30 MJ of energy. enough to accelerate an object of the same mass to 7.7 km/s. which is almost escape velocity on earth (11.2 km/s), or enough velocity to shoot the object out of earth's gravity field altogether.
(a kg of oil, ofc, costs about $1)
This plane can't carry passengers. All the useful load is taxen up by batteries. It's the fundamental issue with all-electric aviation
Well, feel free to correct me on my math here, I'm no battery expert. Google says a 100 kWh battery typically weighs between 1000 and 1500 pounds. Since we'd need 6618 kWh for the hypothetical trip from Cleveland to NYC, that means we'd need 67 x 100 kWh batteries which would weigh between 67,000 and 100,000 pounds. Google also says the typical fuel load for a 737 is around 50,000 pounds, so the relative overage from batteries (since obviously you wouldn't need to carry any fuel) would be 17,000 to 50,000 pounds. This would roughly give you a passenger capacity range between 120 and nobody. Even worse if you consider the need to have some reserves of power for unexpected circumstances. There's also the problem mentioned elsewhere in this thread that the batteries don't become lighter as they're discharged, so your landing weight is the same as your takeoff weight.
So yeah, battery weight is the core problem. But if battery weight comes down by "just" 50% (and I have no idea if that's on the horizon or not) then electric aviation becomes quite viable.
There is nothing in labs to even suggest that battery capacity in the next 20 years.
OK, electric planes are fucked then. No wonder they're resorting to "$5 of electricity" clickbait bullshit.
What about Flintstones style breaks, where everyone's legs stick out under the plane and they need to use them to stop?
Sure, it wouldn't be effective, but one or two of these new flights being on the news and global emissions would be down even farther than with your plan.
I was about to crunch the numbers to check for myself, thanks for doing it, you did a great job.
Amazes me how they made it work considering the amount of arcane shit it takes to make jet engines work. Of course it is possible since electric motors are torque monsters, but it still must've taken insane efforts to make it work.
I wonder if we'll see these flying anytime soon or if they'll get shot down by the fossil fuel i industry just like everything else that is amazing
It will never practically work unless there is some fundamental new technology to store electrical energy, and the periodic table says no.
It will be too hard to time landings and take offs at small ports, but if you replace this with a massive flywheel you can have gearing to both spin it up on landings and draw from it to launch.
Wouldn't work Militarized though because you wouldn't be able to refuel it mid flight.
Microwave beams from satellites. What could go wrong?