Technology

People down here acting like $5 to keep 25,000 lbs in the air for 30 minutes is not a milestone worth announcing.

"Be perfect NOW" 🤣

Time to pass those savings onto the ~~consumer~~ shareholders!

If they can fly a small airliner for 30 minutes for $5. Either there's a whole lot they're leaving out. or they're not paying anywhere near what I pay for electricity.

They say the engines delivered more than 1 megawatt of power. Cool, so 1 MW over 30 minutes. That's 500kWh. Which means if they paid $5 for it. They paid 1 cent per kWh. Now i don't know about you guys. But i sure as hell don't pay 1 cent per kWh.

they also dont specify how many kwh they used. which is why i assumed a sustained 1mw of power. they also dont say how much the plane weighted. only what it could potentially carry. that doesn't mean that's what it weighted in the test.

don't get me wrong. cool stuff to fly electric planes. but i can't help but feel incredibly sceptic when they leave out a lot of numbers while making the insane claim that they only used $5 worth of electricity.

It just occurred to me that with the recent advancements in cargo-container-sized nuclear reactors, they would excellent fit to power aircraft due to their high energy densities. There were attempts at nuclear-powered aircraft in the past using older technology, but IIRC they irradiated crews and were primarily for bombers carrying nukes that would supposedly need to be in the air continuously for days at a time.

Good and as battery technology improves, EV aircraft would be ideal for short commuter hops.

Oh boy... So, they took off from a test facility adjacent to Plattsburgh International Airport. I don't see it stated, but I give it 98% they landed where they took off. Plattsburgh has some of the lowest residential and commercial electricity costs in the country, so that $5 nets them about 110kWh of juice.

They also reached a maximum altitude of 1,100 feet with a plane that weighs in excess of 25,000 pounds. Lifting 25,000 pounds up to 1,100 feet takes 37 million joules of added potential energy, or a bit above 10 kWh.

The entire remaining 100kWh of energy budget is the equivalent of accelerating the 25,000 pound aircraft up to 252 meters/second at perfect efficiency in a vacuum. This flight was not going very high, and it was not going very fast.

If the economics of their hybrid idea work out, it'll be fantastic, but the attempt at marketing over transparency here doesn't fill me with optimism.

Heart Aerospace is claiming that the hybrid-electric ES-30 could reduce airline costs of operating regional aircraft by more than 40 percent.

How much you want to bet that this 40% savings will never make it to the customers' pockets?

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 in electricity" but surprisingly small.

Feel free to check my math, my brain hurts.

Is there no simple anymore? Plane A went this far on 5 dollars electricity. Plane B went the same distance on X dollars worth of jet fuel. I want to know the distance travelled and I want to know what "X" is.

i just got back from a week in bali. we rent a mini ev 2 person car to get around and in the span for the whole trip we literally spend $0 because we charge them off the wall plug of the villa we stay at

but if we want to be pedantic the car is Wuling airev and iirc it has 17 kwh of battery. that is quite enough for us for the whole week, we only need to charge it once at 60%. so lets say its around 7 kwh. in Indonesia a kwh cost around $0.1. so for a whole week it only need less than a dollar for 'gas'

In other words the Us won’t use this technology because it hurts the oil companies pockets

Every time I hear of an all electric aircraft of any size, I always wonder what they're going to do about landing weight.

Every modern transport category jet has a higher takeoff weight than landing weight, because of the simple unavoidable fact that landings are rougher than takeoffs. Taking off, the load gradually comes off of the landing gear, on landing it's suddenly applied. Jets burn tons, literally tons, of fuel enroute, so they're considerably lighter on approach. It's why aircraft have dump valves to jettison fuel overboard in case of forced landing early in the flight.

Batteries don't get lighter as they're discharged, so...?

This article is idiotic.

$5 cost. 25,000 pounds. BUT OVER WHAT FUCKING DISTANCE?

$5 gets me 23 miles in my Delica. It gets me 100 miles on my motorcycle. It gets me 30 miles in my Porsche 914. But the article says nothing about distance.