First test flight of largest all-electric aircraft used just $5 of electricity
5 days ago by FoxtrotDeltaTango to c/technology
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.
Well, the data we do have is that the flight was just under 30 minutes and very likely under 100 miles.
From the Wikipedia on airline fuel efficiency:
The worst-performing flights are short trips of from 500 to 1500 kilometers because the fuel used for takeoff is relatively large compared to the amount expended in the cruise segment, and because less fuel-efficient regional jets are typically used on shorter flights.
In the example values table, the most efficient plane for a 560km trip burns 0.92 kg of fuel per km, so doing some rough math and assuming the electric plane travelled 100 miles, that would be roughly 148kg of fuel, or 50 gallons (190L).
At current jet fuel prices ( $3.76/gallon ) that's about $188 US in jet fuel as a rough estimate. It's unclear if the test flight went up to full altitude or if the plane was at full weight, so a fair comparison might have used even half as much jet fuel.
Edit: From some of the other comments, it seems like they might have only considered flight time as cruising time, not takeoff and landing, so my numbers will be quite far off if that's the case. My gut feeling is that this is probably the case, because this seems like too big a difference otherwise.
$5 of electricity to lift an airplane 10,000 feet definitely seems low.
If you want to be really smug, you could say a gas powered plane requires $0 of fuel to glide for 30 minutes
Now that you mention it, they specify a maximum total weight of 25,000 lbs, so at 100% efficiency it would take 339MJ of energy to lift the fully loaded plane to 10,000 ft. That can be converted as 94 kWh, and at the current cheapest electricity price in the US of $0.1235/kWh, that's $11.63
Therefore, it is literally impossible for this plane to reach 10,000 ft for $5 fully loaded.
price in the US of $0.1235/kWh, that’s $11.63
Way cheaper than I'd have guessed.
737 at max takeoff weight is 175k lbs. So that's around $80 to get airborne. Seems like a steal when you're charging easily triple that for one seat.
The plane only went 100 AGL. It has a service ceiling of 2,000 feet AGL
This plane has massive wings, making it incredibly good at gliding (for its massive weight)
As far as I can tell from public information, they climbed to 1,100 and glided the rest of the time to land
Jets are less efficient because they're designed to carry large amounts of cargo and/or passengers. This plane was at near max weight, 25,000 pounds, with zero cargo or passengers
The entire thing had to be stripped down. Single pilot op because they didn't have the capacity for a 2nd seat and pilot
All this "jet" can do is transport its own batteries short distances, slower than a Cessna 150, and very low altitudes
27 minutes of slow flight in a 150 at high density altitude, well leaned out, would cost about the same and have the ability to carry a passenger
This plane is nothing more than a marketing ploy. At least it's quite effective at that
$5 for 30 minutes in the air. pick any speed you want. it doesn't matter. avgas and jet fuel don't compete with $5.
I pick 30 minutes at Mach 7
How long do you want to spend at Mach 7 relative to stopping and starting? Because that could be a lot of G-force.
Meh just accelerate with F-force and then switch to G-force when you are up to speed and vice versa when slowing down, problem solved!
I want people to find my face at the starting runway, and my skull in some field 7 miles away from where the plane landed.
i definitely won't be in your way. bring back pictures.
$3.60 for mogas at a couple places near me. Very high density altitude, well leaned out, in slow flight, you could get 27 minutes out of a 150 for $5
These guys are also apparently getting electricity for 2-4 cents per KWh, which is many times cheaper than most would be able to get it
You'd even have more useful load than this "jet" that can carry no passengers or cargo
You could also fly a glider. It'd be as useful as this thing
Wrong thread buddy. Maybe you need a refresher in navigation theory.
The site for the plane manufacturers says they have a max range of 125 miles.
So this is practically useless for flights. It's faster to just drive 125 miles in an EV.
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.
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.
Don't you dare talk about catapulting using electric technologies in America though. Steam only! 🇺🇸🗽🦅🏈
I didn't say which type of catapult. I don't need ICE showing up at my door.
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.
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?"
The Navy is stupid.
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.
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!
National average it's 55¢ 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.
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.
Since a plane requires the most thrust at takeoff, you could use ground-based
Actually dragging (or wheeling in) a wire or having a wire car supplying the plane with electricity during takeoff would work too.
I think the only realistic use case is going to be short trips. For long range offsetting the carbon for jet fuel just makes more sense.
But really small personal vehicles could be interesting. There is the Pivotal BlackFly which can VTOL and uses less electricity than a big electric car - and it needs to roads. So for commuting this could actually work to save on infrastructure.
The biggest problem with flying cars is, well, have you seen how people drive?
It's stressful enough just crossing the street. But at least you know when you're doing it, look both ways, look around for idiot drivers. If there were flying cars you'd always be in danger everywhere.
look both ways
Which many don't regularly do and now added vertical dimension, more directions to look.
Can you imagine the chaos of hundreds of thousands of flying cars all trying to takeoff or land at the same time during morning and afternoon commutes. It would be glorious to witness, minus the human carnage. Even with the help of air traffic controllers there are still collisions with the current volume of air traffic. In a word, unworkable.
Two obvious solutions to traffic congestion in the US are work from home and replacing the public transport networks that automobile and oil interests dismantled.
Yeah and airplane pilots have to do a whole lot of training before they're trusted with flying.
And yeah, 100% agree on better public transit and more WFH. We've developed technology to do this but somehow people insist that we should all sit in moving metal cages surrounded by six lanes of other people in their metal cages every day so we can have a Teams meeting with the person sitting next to us in the office.
Actually dragging (or wheeling in) a wire or having a wire car supplying the plane with electricity during takeoff would work too.
After doing more of the math, I realized that the energetic cost of takeoff is quite a small fraction of the overall cost. So the only real benefit of the catapult would be to reduce the size and weight of the propulsive machinery on the plane. So externally providing just the electricity wouldn't be much of a benefit.
This is a pretty bananas idea, but I wondered if in the future we'll be able to have something like a large robot arm "throw" a small plane from the top of a skyscraper as well as catch it for landing. Something like a modified trebuchet, slowly storing energy in a suspended weight to power throwing the plane, or to store the energy from catching the plane. We'd probably need further advances in robotics control, and the arm might need to be too heavy to be fast enough. And overall this makes even less sense than a catapult / puller that is already in use for gliders.
To do that, you would need a short acceleration of 3-4gs. That's like 900-1200lbs of force on husky Americans l
For extra fun, you could have landing planes snag a wire and use their momentum to accelerate a plane taking off.
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.
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.
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)
Wouldn't work Militarized though because you wouldn't be able to refuel it mid flight.
Microwave beams from satellites. What could go wrong?
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.
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.
Literally the first sentence:
The first flight of the largest battery-electric aircraft to take to the skies lasted nearly half an hour while costing just $5 of electricity.
Can your Porsche 914 fly for half an hour on $5 of fuel ?
It would have to be a very high cliff.
If humans can hang glide I don't see why we couldn't use those aerodynamic principles to try to glide a car hooked up to glider wings. It's a real engineering challenge, but I feel like it would be possible to get some distance in a scenario where a car uses its wheels to go fast, drives off a cliff, deploys some kind of glider wings (or drive with the glider wings timed out to where the car gets to the cliff edge right at the point where the wings plus updraft provide enough lift) to get the vehicle to glide a substantial distance.
Seems horribly dangerous but not impossible.
Or have a really strong updraft
I can fly a glider for half an hour for $0 in fuel or electricity
In the right conditions I can fly a Cessna 150 for $5 in fuel. Just have to shop around the whole country for cheapest fuel and best flight cknditions. So exactly like they did
These guys have the cheapest electricity in the country considering they advertise 1MW power output that apparently only ends up coating $5 over 27 minutes
EVs make a lot of sense. This plane does not, nor does any currently proposed design for an all-electric plane
My 1975 was tuned for distance. When I drove it from Key Largo to Seattle, it did 35mpg average over the 3500 miles I drove. That car was lost in an accident, sadly.
25 miles per gallon. 30 minutes would be 12.5 miles on half a gallon.
My current one does about 25-30 mpg. It weighs 1950 pounds. So, yes. It can comfortably do half an hour on one gallon or so and have fuel left to get me to a refill.
They have flat 4 two liter VW engines. Extremely efficient if tuned correctly. One top of that, there is a direct 1 to 1 drop-in electric kit for these. When my current engine dies, I have an electric kit I'll put into it to make it an 914E.
I used to drive a '76 Rabbit that got 40 mpg (and with a carburetor no less). Unfortunately, it had no chance of passing an emissions inspection and not much chance of surviving even a low-speed collision.
Point to me in your quote where it talks about distance.
LOL.
"ErRrR pOiNt tO Me iN yOuR..,."
Let me spell it out for you.
The achievement being reported is that the plane performed a 30 minute flight. The implied details being that it took off, flew around in circles, and landed again at the same air port.
The distance the plane traveled is not the achievement and it's not relevant.
$10 an hour still seems really good though right? I'm not sure how much Airlines pay currently for fuel though.
Only article I could find was this: https://flyinginsight.com/...
On average, a 737 or A320 consumes between 2,500 and 3,000 litres of fuel per hour
Take a typical two-hour flight, such as Amsterdam to Barcelona. The total fuel burn would be approximately 5,500 litres. At a reference price of $0.59 per litre, that translates to around $3,200 in fuel costs.
So that's $10 an hour down from $1600 an hour? Seems decent.
The X1 demonstrator is more comparable in weight and power to an EMB 120 Brasilia, a 30-seat turboprop. Forum chatter seems to indicate those burn around 1000 lbs per hour, or $335/hr in fuel using the $0.59/liter price you mentioned.
Dropping down to $10 is still pretty decent lol
Heart aerospace's website indicates the X1 demonstrator has a 140kt "VNE" - never exceed - speed. So it's probably safe to assume cruise speed would be closer to 100kt, and $5 of electricity used in half an hour might equate to around 50nm straight line distance.
It's pretty impressive for a plane roughly equivalent in size to a 30-seat turboprop airliner like the EMB 120
The first flight of the largest battery-electric aircraft to take to the skies lasted nearly half an hour while costing just $5 of electricity. That aviation feat comes at a time when jet fuel prices have skyrocketed because of the US war with Iran.
At what airspeed?
Did you reply to the wrong comment because you're quoting time, not distance?
Why would you leave behind a perfectly nice airstrip when your goal is testing a new aircraft? One step at a time, Speedy. Aircraft distance depends on altitude and winds. Not the goal of this flight to break this kind of record. Easier things like time come first. Only then can they calculate how far they can go. Aircrafts can't park on the shoulder like your 2D vehicles do.
The plane has a max range of 125 miles.
More US electrical bullshit to swindle investors.
With horse power and cargo capacity an airplane has I really doubt it
That seems like really bad efficiency, or really expensive power. I used to have a Nissan Leaf that would do over 5 miles to the kW. Even with rather substantial battery degradation, I could get 80 miles to a charge, and a full charge would run me about $1.25 at the local utility rates.
Charging at home vs public charger, driving speeds, hilly terrain, etc.
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?
Ticket prices will in fact go up because they had to spend money on these new planes.
How would they ever recoup their cost? Do you even capitalism bro? (/s)
For most airlines the biggest cost is fuel, they reliably make the money back on the planes themselves because they run them for 30 years, so it's a long-term investment but it will pay off.
Over the 30 years this aircraft could theoretically be in operation fuel costs are going to skyrocket. So not only is it saving some money today, it's saving a lot of money tomorrow. We may even get to the point where aviation fuel becomes literally unavailable, an electric aircraft like this is a pretty good insurance policy. But you do have to buy a whole new aircraft, and maybe you've still got 20 years on your current one, so you need to make that money back, and one of the best ways to ensure that you pay off that cost is to have more customers, and the best way to have more customers is to have cheap fairs. You can afford cheap affairs because you'll feel costs a lower.
Airlines almost never own an aircraft. They sell to banks and lease back, so they have smooth annual OPEX costs, not large CAPEX costs every few years.
"Every few years?" You mean every 14 years, right? And this article was even nearly 2 years ago, so theyre probably even older now: https://www.independent.co.uk/...
You know what would be a good win? Charging customers the same rates to power their homes as the operators of this aircraft.
Question is, are they actually gonna use them now?
If there are savings, it would make it in customer's pockets. Aviation is incredibly competitive
I would, however, bet against them ever achieving that savings. Maybe they can find a battery-electric hybrid configuration that shaves off a percent or two, but I find even that unlikely
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" 🤣
Because they didn't. And anyone that is capable of critical thought can easily take the few numbers they provide in the article and do some simple calculations.
They claim the motors pull more than 1mw of power. So using 1 mw for 30 minutes is 500kWh. That means they paid 1 cent per kWh. (Spoiler. They dont)
And nowhere, does it say the plane weighted 25000 pounds. It says it "can exceed" 25000 pounds. But by no means does that mean that's what it weighted in this test.
The most likely scenario is that the plane was bare minimum rather than maximum. I doubt even passenger seats were installed.
This plane is a piblicity stunt and will never be a viable product (the company itself said it is not meant for commercial production)
This "jet" has a lower max speed than a Cessna 150, a service ceiling of 2,000 AGL - far less than any commercial aircraft. It weighs 25,000 pounds with no passengers or cargo, almost certainly it's max weight. They can't even fit a 2nd pilot
They do not disclose how much energy was actually used, just a vague "$5" figure and a listed max power of 1MW
It's just a marketing ploy and you fell for it
What you need is a cookie. Cheer up.
There are also flights where this could be used as fully electric right now, or very soon if they increase range a bit. If you fly from Tallinn to anywhere via Finnair, you go through Helsinki, that's like a 30 minute flight. And the reason you don't just drive to Helsinki is that you'd have to take the ferry which costs more money, takes over an hour and the Helsinki airport isn't that close to the port.
Similarly, you can fly from Tallinn to the two bigger islands here in Estonia, very short flights versus like a 3 or 4 hour bus ride involving a ferry. 30 and 40 minute flights with the current 30-40 person planes that company uses.
There are plenty of flights where 30 min in the air is enough. The general public seems to only consider trans ocean and regional flights but there are plenty of uses cases they don't see.
In other words the Us won’t use this technology because it hurts the oil companies pockets
I'm guessing autocorrect swapped "US" with "Us."
At this point we’ll stop ourselves
I did my best to find any technical data about the flight. Couldn’t find any actual numbers. FWIW it’s not intended to be a standalone method of powering the aircraft for commercial use; they plan on making it a hybrid, which makes far more sense as far as range and payload are concerned. Best guess a 25000 lb aircraft like this will probably cruise around 120-150Kt at a nice, slow, efficient airspeed for a test like this. So maybe a 40-50 mile flight because “air time” probably started as soon as they lifted off.
Yeah the problem is they also don't tell us the load during the flight. From the lift equation (let's be hand wavey) if they're a similar size to a regional jet (same planform area) your heavy lift is better driven by speed than lifting coefficient. Of course, it's hard to go fast with electric props, so I wonder if a safe ceiling is probably 400Kt 300Kt?
Gives a nice range of you know... 40 to 200 150 miles.
Edit:
No way. The speed record for a prop aircraft currently stands at about 300Kt. If we use that generously our new ceiling is lower.
It’s right there, friend.
25,000lb. Reading the article it says “more than 25,000 lb”.
We should assume they used a highly efficient airfoil that can maintain the most efficient possible cruise for the demonstration aircraft probably at L/D max if they’e looking for time aloft, so I doubt it’s even worth considering top speed or ceiling. It would be interesting to know what NACA profile they used and what the top speed characteristics would be.
Edit: looks like a Vne of 140 Kias. This is not a fast aircraft. Also a minimal useful load. If you make a couple clicks through to the site of the test it’ll give you more info.
The first flight of the largest battery-electric aircraft to take to the skies lasted nearly half an hour while costing just $5 of electricity.
The X1 aircraft is comparable in size to a small regional airliner and can achieve a maximum takeoff weight exceeding 25,000 pounds with the help of four wing-mounted electric motors. The battery-electric propulsion system delivered more than one megawatt of power during the maiden flight.
It doesn't tell us what the load was for the test flight at this price point.
You're probably right that it is good and slow and much less weight.
Likely a short flight.
Time to pass those savings onto the consumer shareholders!
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...?
You can rethink the engineering with electric motors.
The planes you are describing are designed assuming they will be lighter on landing because of fuel. So why design them for take off weight?
Electric motors are condusive of blown wing design for example, and would have a unique landing profile. (The plane can land at much slower velocity)
Edit: yeah they've moved the engine shroud which allows for lower speeds. Given the same runway you would be able to trim vertical speed.
That ain't gonna happen on a civilian airliner.
Blown wings are basically powered lift. You're planning on bringing a civilian passenger plane down final approach at a speed it can't glide at if the power plant fails?
I could see that for a carrier based aircraft where STOL is a factor but no you're not doing that in airline operations.
Why couldn't it actually be safer since you could have distributed power centers, across multiple motors?
You could also have hybrid approaches - there is space between not being able to glide and smashing your landing.
I'm just getting at it being a different system so some old assumptions can be reexamined.
Bigger challenge than landing is energy density.
Regardless it's a very interesting space.
Multiple redundant motors are heavy.
You can rethink the engineering with electric motors.
One of the other limitations is that you're stuck with propellers if you're using electric motors, so your top speed is going to be significantly slower than jets. Unless you do the Tu-95 thing with contra-rotating props whose tips exceed the speed of sound, and then you have monstrous noise problems.
Fun fact, batteries DO become lighter when they discharge. But obviously not like fuel. But it's still a fun fact.
FYI 1 kg battery when fully discharged loses about 10⁻¹² kg of its rest mass ...
The same way we make bigger aircraft with higher landing weights: beefier landing gear and structural reinforcement. Airliners don't have a lower max landing weight than takeoff because they have to, they do it because it's cheaper and more efficient. Add some more structural weight and you lose some payload, but if the efficiency gains from fuel cost savings make it worthwhile, then manufacturers will make them.
You'll hit a point where the payload is so poor it isn't worth operating.
That’s true regardless, batteries will never power intercontinental wide-bodies (short some major new developments in battery design). This will probably reduce the maximum aircraft size where batteries remain viable, but they are obviously very viable for short hops in small jets, the point where they cannot compete is somewhere but it’s not “never”, even with this limitation.
That all said, maybe someone will explore just dropping batteries along the way? It sounds ridiculous, but it also sounds like something we have the tech to solve…
It's a bigger deal on bigger aircraft, but on mid-size narrow bodies it's not as much of a problem. A 737, depending on the model, only has a difference of about 20-30k lbs between MTOW and MLGW and no fuel dump capability. An overweight landing isn't really a big deal in one, just a quick maintenance inspection. Closing the gap so MTOW and MLGW are equal is doable. It's hard to overstate how huge of an expense fuel is to an airline, if they have to lose some passengers and cargo they would absolutely do it if it got rid of the fuel expense.
Of course all that is contingent on having batteries with enough energy density to get somewhere close to current MTOWs while having something of a useful range.
That's ridiculous. No one on final gives a crap about take-off weight. What you need is a ride in a glider or parachute. Learn to land on your ride's minimal weight. Dropping stuff is only an extra measure if possible, not a necessity.
when r/fuckcars thinks they know anything about aviation.
↑ when a video game pilot thinks they know anything about aviation ↑
I'm a CFI.
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.
An experimental plane to help develop a future hybrid still another experimental phase away that will still be limited to regional travel due to autonomy issues. Still pretty awesome, but still some time away.
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.
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.
Thank you for that.
They didnt say the planes weighted 25000 pounds. They said it could exceed 25000 pounds. My guess is that not even the passenger seats were installed in this run.
1mw of power from the 4 engines. For 30 minutes, 500kWh. So for $5 they paid 1 cent per kWh. Somewhere there's a bunch of bullshit hidden.
Well, its possible the motors weren't at 100% at all times, but I'd imagine that at that maths its still 1-2 cents per kWh, which still seems quite off.
I looked it up quickly to get some context. Google (alphabet). Which is a huge consumer of energy. Has deals directly with the electricity producers. It's reported they pay ~4-12 cents per kWh in the US, depending on where the energy comes from.
And they can get those prices because they are an enourmous customer that can sign multi-year deals that benefits the producers ability to expand production.
So... i would love to know how this company managed to get rates around 1-2 cents per kWh
I give it 98% they landed where they took off
They did. It can bee seen in the press release photos and the video they released
so that $5 nets them about 110kWh of juice
They would have needed more than that. Likely got some lower rate somehow
This flight was not going very high, and it was not going very fast
Vne, max airspeed, of this plane is 140 knots (72 m/s). Less than a Cessna 150. Max altitude is 2,000 feet AGL, significantly lower than a Cessna 150
If the economics of their hybrid idea work out, it’ll be fantastic
It would be, but I highly doubt it. Energy density of batteries is simply too low. This plane can barely fly at slow speeds with no cargo or passengers, and with a cockpit stripped down to a single pilot. Hybrid thrust would be heavier than either jet A or battery-electric, and it still has the downsides of including batteries for the entire flight
Hydrogen or nuclear will be viable before battery-electric in aviation
I can understand a hybrid train because of certain sections of track electrification issues and the fact that diesel electric is how even trains that run entirely on diesel operate so you're essentially just toting around a generator to operate your already electric engine. I understand hybrid cars with regenerative braking and range extension. I don't really understand hybrid planes.
Like I can imagine electric is more efficient for takeoff because electric engines produce more initial power generally than what fossil can match per engine size(a big part of both hybrid trains and cars both using batteries for initial acceleration) and then you cruise with jet fuel. I'm just having a hard time imagining it is worth it from a defossil fuel perspective or from a straight efficiency perspective.
Combustion engines have maximum fuel efficiency at a specific RPM. A Hybrid has the advantage that you can run that engine at maximum efficiency 100% of the time and using the generated electrical energy to generate motion. The gains by being able to keep the ICE at peak efficiency are more than the loss you take from the conversion. That's the same principle as in hybrid cars - look up Technology Connections video where he analyzes the behavior of his hybrid car. It is for sure preferable to than just the ICE directly, losing a lot of efficiency and therefor fuel because of differences in needed power output. Combining this into a plugin-hybrid makes - as you said - the takeoff use no or just the default amount of jet fuel at all.
This will not eliminate the need for jet fuel, but even a reduction is preferable to the status quo. Until we get batteries that are light enough while keeping energy density at least as high as now (preferably higher), purely electric long-range flight is not an option that's available.
I don't think you'll ever get there for flight personally. Just need to accept synthetic aviation fuel as the only real option for energy density (both volume and weight) and accept certain modalities being absolutely priced out of air transport.
I guess my main issue is you're now flying around with those takeoff batteries and extra engine components. Is that really ever going to be worth it for anything but those short hop flights this is designed for? And if not why are we even investing in this because those short hop flights frankly need to be eliminated for trains anyway.
But why you dont believe it? OP gave a detailed rebukal of your initial post, and then your answer is "I just don't believe, just accept that ..."
You want to know why I don't believe we'll get batteries with enough energy density for sustained long haul flight? I was responding to their last sentence. Ya know, acknowledging that batteries more dense than hydrocarbons isn't really on the radar so for that aspect of things synthetic aviation fuel is pretty much what you gotta accept to go for zero carbon. I had already agreed with them that it's potentially more efficient in takeoff in my initial post. They just expanded on why. I frankly am perplexed at what you think I'm dismissing since we largely agree.
And if not why are we even investing in this because those short hop flights frankly need to be eliminated for trains anyway.
Well, islands and other geographical features still exist in some places to provide geographical and geological barriers to train connections between certain city pairs.
Some military tanks are going hybrid, too, despite not really being able to move very far on the electric battery. It's still worth it for idling and running the on-board systems without actually running the fossil-fuel-burning engine, though, and is potentially a stepping stone towards greater improvements in the electric drivetrain for quieter and more energy efficient movement.
With how warfare is currently evolving, i do not see much future for MBTs in general, at least not in the amounts that were produced before. Drones simply kick the shit outta them while costing a fraction.
What if the worthwhile goal and priority were in fact to "defossil"?
What do you mean? I favor synthetic aviation fuel derived from hydrolysis which is very lossy on energy and would largely kill most current air routes in favor of trains. I think a 40x price increase on fuel is likely, but the actual implementation is proven since it's essentially plug and play with existing infrastructure. I think the best way to make up for the subsequent loss of profitable air routes is electrified rail. This tech isn't for getting off oil though, it's for reducing use at best and if it actually does improve efficiency it would be used along with synthetic fuel.
i also prefer electrified rails, but i'm fine with decarbonizing aviation where rails aren't feasible. rail construction has thresholds to meet in terms of travel density, frequency, and ground conditions.
Good and as battery technology improves, EV aircraft would be ideal for short commuter hops.
Dude, I'd take short hop flights all the time if they end up being that environmentally friendly.
I really hope this will catch on for once, it could be a great solution for all those people who insist they have to do domestic flights... (in countries like Germany which aren't that big comparatively speaking)
Yeah unfortunately this is only viable for extremely short flights 100-200 miles as the article says. Batteries are just too heavy and planes needs too much power for anything more.
These would be the perfect private jet for the ultra rich who take a jet to work a few minutes away, or to go shopping, but for commercial flights they’re basically not an option until we have a huge breakthrough in battery tech. We need the mythical “coming next year” for the last 20 years “solid state batteries”.
IIRC take off and landing is using a huge portion of the fuel needed in regular planes. If you can use this new technology to do those manoeuvres, it would also be a big win for general flights.
Yes and hopefullybreduce pollution and noise levels around airports
Yeah that's it. It's not a matter of "catching on", it's a matter of better battery tech emerging which is more affordable.
Personally I think high speed rail is a better bet. All the tech already exists and the weight of the batteries is less problematic.
Yep definitely. I have to question the $5 of electricity claim though. $5 of electricity would barely even get an electric car that far. What size are the batteries? Where did they get this incredibly cheap power to where it can output over a megawatt of power?
As I said in another comment, this is a step towards making a more efficient hybrid plane for trips under 500 miles, of which about 4 million are made per year in the U.S. alone. Having enough battery power to take off efficiently makes those trips a lot more economical. On longer flights, fuel for takeoff is a lot smaller portion of the overall costs and doesn't matter as much. Except for all the fossil fuel burned, of course.
Yeah and I agree, that’s a great step that hopefully will come to fruition soon enough. I’m just saying that people need to temper their expectations because full electric passenger flights, especially long haul, are simply not possible with existing battery technology, not even close.
People who insist on domestic flights in Germany are really critiquing the train network which is vast, but way to slow and the on time performance is terrible. If they would fix the trains there would be much less call for flights.
Better than the US is not an endorsement.
Fixing public transport would solve so many of Germany's issues to be fair
thanks for using Leebra!
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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'
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