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The largest electric aircraft just flew [video]

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Re: The largest electric aircraft just flew [video]

#271

Post by ddlsmurf »

ragebol wrote: post #246
ddlsmurf wrote: post #226

Earlier quoted context omitted.

I'd dispute they do any of those better, they stole the IP, then used public funds to make cheaper versions in the hope of leading the markets, including by being artificially more affordable while there is any competition. Besides electric cars and solar, it's very debatable wether those will actually be ecological in the end. For ex. they are still opening massive amounts of fossil based electric plants, so the tru…

> used public funds to make cheaper versions in the hope of leading the markets, including by being artificially more affordable while there is any competition If you replace 'public' with 'VC', isn't that the exact same as the US does in Silicon Valley?

if VCs didn't care about making their money back, but instead had very different interests, then somewhat

Re: The largest electric aircraft just flew [video]

#272

Post by athrowaway3z »

class3shock wrote: post #155

Doing some math. Regional jets get somewhere around 45.9 seat miles per gallon (1). So 30 seats, going 125 miles would take around 80 gallons of jet fuel. This is likely low because all the jets listed are bigger and likely flying longer flights that are more efficient but just go with it. Jet fuel has a specific energy of 12 kwh/kg and a density of 6.7 lb/gal (2). So 80 gallons of jet fuel is 536 lb, or 243 kg, and…

The economics to do what planes do today make no sense; but i think that's making the analysis the wrong way around.

There are opportunities for which airplanes have never made economic sense because they have big fixed costs like pilot, hangar, fuel-infra, engine(-maintenance). So will small short haul (?pilot-less) rechargeable planes have enough allure to beat out alternatives where planes were never considered before?

probably not at any major scale in a future where it competes with other autonomous transport, but that's me guessing at numbers. There will be enough of a market to build these things for niche constraints (eg the fuel-infra if small modular reactors become widespread).

Re: The largest electric aircraft just flew [video]

#274

Post by ZeroGravitas »

ddlsmurf wrote: post #270
ZeroGravitas wrote: post #259

Earlier quoted context omitted.

Running trucks on a 50% coal grid like in China makes both economic and environmental sense. It makes more of both as the Chinese grid gets cleaner.

neither of those are true, if they were, remember when tesla wanted to sell trucks like 10 years ago ? if you use electric trucks, half the mass you pay to move around is useless. Also the grid isn't "half coal", the truck doesn't wait for the sun to come out to charge. Which is another cost to transporters: the hours of downtime to recharge. They only make very limited sense in very last mile scenarios in dense citi…

Solar is only about 13% of China's power. They have hydro, wind, nuclear and gas too as well as coal.

Their off peak prices have generally been overnight, ideal for truck charging, though they have started having them around noon too like many other nations with growing solar share. Great for a mid shift top-up.

Coal is worse to burn than gasoline, but a car engine throws 80 percent of that away so you have to burn more compared with an efficient EV.

This has all been debated to death for over a decade, MIT has interactive tools to calculate figures, there's really no excuse for not knowing this about a subject you are so passionate about.

Re: The largest electric aircraft just flew [video]

#275

Post by cuu508 »

dyauspitr wrote: post #164
luma wrote: post #87

Earlier quoted context omitted.

Hybrid after the first 125 miles, total range 500 miles. Their problem is diversions - an incident at the destination airport may mean an passenger aircraft may need to land at an airport which could be a couple hundred miles away. The hybrid powerplant throws the fuel efficiency numbers off so goal is not to run it unless needed, but they could not get certification without it.

Unless they have a whole new airport and flying experience, I don’t think a lot of people are going to fly just 125 miles. That’s less than two hours of driving. It would be 2 hours of just airport shenanigans much less the flight itself.

> 125 miles. That’s less than two hours of driving.

Assuming you have a straight road in that direction with a speed limit that allows an average speed of more than 100km/h.

Re: The largest electric aircraft just flew [video]

#276

Post by kibwen »

ticulatedspline wrote: post #157
class3shock wrote: post #155

Doing some math. Regional jets get somewhere around 45.9 seat miles per gallon (1). So 30 seats, going 125 miles would take around 80 gallons of jet fuel. This is likely low because all the jets listed are bigger and likely flying longer flights that are more efficient but just go with it. Jet fuel has a specific energy of 12 kwh/kg and a density of 6.7 lb/gal (2). So 80 gallons of jet fuel is 536 lb, or 243 kg, and…

This graphic always reminds me why it's so hard to beat gasoline and that batteries kinda suck. https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...

Energy density alone is a misleading metric, because what matters is how much energy actually gets delivered to the drive mechanism. It's actually not that hard to beat gasoline, because despite its excellent energy density, gasoline engines are only 30% efficient. First and foremost a gasoline engine is a machine for producing heat and noise, and only incidentally for producing forward motion.

Re: The largest electric aircraft just flew [video]

#277

Post by notahacker »

ddlsmurf wrote: post #265
cpt_sobel wrote: post #253

Earlier quoted context omitted.

> they stole the IP, then used public funds to make cheaper versions in the hope of leading the markets If you steal my IP and you make a better - or at least comparative but cheaper - product, that's on me for not innovating further.

It's trivial to compete if you don't have R&D costs, and don't care about stuff like your employees, regulations or safety, or even sales since you can just use government money (this is not without consequence either). And it's not only about free market stuff, why do you think they're so excited for all countries to use their 5g products for example ? Don't think this is benign.

There are plenty of legitimate criticisms of Chinese policy, but you should probably reread your arguments and check for coherence.

Chinese EV trucks make no economic sense even though they're 30% of China's fleet but also they're only investing all that as a trojan horse even though they use them almost exclusively domestically, plus the old "Asians don't innovate they just copy" canard even though there wasn't much Western IP on electric trucks to copy in the first place and China's battery technology is somehow not Alibaba knockoffs but more performant than Western equivalents (whilst state sponsored Chinese industries remain generations behind in stuff that's actually strategically critical for them to clone via industrial espionage like semiconductors and jet engines)

Re: The largest electric aircraft just flew [video]

#278

Post by Toutouxc »

echoangle wrote: post #268
Toutouxc wrote: post #194

Earlier quoted context omitted.

I still don’t see what the problem is. The entire flight was likely just a few patterns and your earlier figure of 100 kWh (let’s assume they get their electricity for cheap) is already a serious amount of energy. It takes 100 kWh of energy to lift a 10.4ton object by about 3.2 km, so we’re obviously in the same ballpark for the maiden flight, and the rest is just drag. For drag, I’ll approximate the plane fuselage a…

> A 737 has a lower drag coefficient than my car Drag coefficient is about the shape and needs to be multiplied by area to get drag. Your car is a lot smaller when viewed from the front than a 737. And there's no way a plane flying at the speed it does has the same drag losses as two EVs.

That’s why I approximated the fuselage as two EVS (the frontal area) and I only looked up the drag coefficient of a 737 because it’s a well-known narrow-body airliner.

I don’t know what speeds they flew, but AFAIK most maiden flights are very tame. My point stands, low hundreds of kilowatthours of energy seems like the right ballpark.

Re: The largest electric aircraft just flew [video]

#279

Post by dghlsakjg »

Toutouxc wrote: post #194
dghlsakjg wrote: post #183

Earlier quoted context omitted.

The specific claim from the company is that the entire 27 min flight was done with $5 worth of power using an all electric power system with a power output exceeding one megawatt. https://www.heartaerospace.com/newsroom/heart-aerospace-comp... I still think it is an amazing achievement. I just don’t see how they were able to get it done on $5 worth of power, or they just quoted the wrong price.

I still don’t see what the problem is. The entire flight was likely just a few patterns and your earlier figure of 100 kWh (let’s assume they get their electricity for cheap) is already a serious amount of energy. It takes 100 kWh of energy to lift a 10.4ton object by about 3.2 km, so we’re obviously in the same ballpark for the maiden flight, and the rest is just drag. For drag, I’ll approximate the plane fuselage a…

The 100kwh number was based on a rate of electricity that is 1/6th the average cost of electricity in the area they did the flight. Even the absolute cheapest rate in that region is 4x the price I used. The price I quoted was a little less than the cheapest published electrical rate in North America, which isn’t in the United States.

So you can barely make it work if you price electricity at a rate that doesn’t exist in the country they did it, using an amount of power that much, much smaller planes usually require to stay aloft (A Cesnna 172, which will struggle with 4 adults, uses 145hp/115kw for takeoff and climbout at a much lower speed). A plane of comparable size and capacity uses 1500-2000 hp turbine engines. That lines up with their own megawatt plus claim.

Regular rates in the area they operate in get them less than 25kwh. They would have had to negotiated a hell if a discount to have pulled it off. And even so, it would be a deceptive claim. It’s like claiming that you doubled the cost efficiency of a 737 (by getting a sponsorship from Shell).

Re: The largest electric aircraft just flew [video]

#280

Post by PaulRobinson »

dyauspitr wrote: post #164
luma wrote: post #87

Earlier quoted context omitted.

Hybrid after the first 125 miles, total range 500 miles. Their problem is diversions - an incident at the destination airport may mean an passenger aircraft may need to land at an airport which could be a couple hundred miles away. The hybrid powerplant throws the fuel efficiency numbers off so goal is not to run it unless needed, but they could not get certification without it.

Unless they have a whole new airport and flying experience, I don’t think a lot of people are going to fly just 125 miles. That’s less than two hours of driving. It would be 2 hours of just airport shenanigans much less the flight itself.

Not much airport shenanigans in the small island hopping nations and the fjords this is aimed at. 125 miles in 2 hours is assuming flat, straight, high-speed, low-traffic roads. Sure, people might not use these to fly SFO → LAX or back, but they likely will use them to go ABZ → LSI, and the "check-in and security shenanigans" are, errr, quite relaxed, compared to what you might be used to at JFK...

There's a ton of small routes that just aren't getting much service now because of operating costs - the founder speaks to that in the video - that this could serve.

A slightly larger aircraft able to do ~300 miles on battery and then say 1,000 in hybrid mode, might resurrect the economically unviable but relatively fast LHR/LGW flights down to NQY. The six hour drive is pretty, but... yeah...

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