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Australia's first electric aircraft has begun test flights

abc.net.au

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Re: Australia's first electric aircraft has begun test flights

#51

Post by seanmcdirmid »

labcomputer wrote: post #49
kevincox wrote: post #27

Earlier quoted context omitted.

Hydrogen fuel cells would also make refuelling much faster. In the video they claimed an hour recharge time for the small plane. While you can get more parallelism as you add more batteries it still seems like making it much faster would be beneficial.

Probably not as much as you'd think, though. Cars powered by compressed natural gas take longer to fill than gasoline-powered ones[1]. I can't find it right now, but Edmunds did a long-term test of a natural gas Honda Civic. One of the persistent complaints was long fill times at public high-pressure stations. Natural gas has about 4x the energy density of Hydrogen, so the problem becomes even worse.

Ya, that explains the huge lineups to fill up natural gas vehicles in Thailand. They have plenty of gas, but the infrastructure needed to distribute it is tricky.

Re: Australia's first electric aircraft has begun test flights

#52

Post by evjim »

TillE wrote: post #25

Are there denser ways to store electrical energy? Hydrogen fuel cells maybe? Seems like you need something much lighter than lithium-ion batteries to even begin to fill the role of passenger planes.

Hydrogen creation using electrolysis is really inefficient. Somewhere under 50%.

Re: Australia's first electric aircraft has begun test flights

#53

Post by [deleted] »

seanmcdirmid wrote: post #47
pkolaczk wrote: post #21

Earlier quoted context omitted.

Typical coal power plants have practical electric efficiency 40% but total energy efficiency is 60-70%, because they produce electricity and useful heat . Also 40% is a theoretical (lab) value for a non turbocharged diesel engine - in practice most engines are operated out of their optimal range, they are turbocharged (a turbo increases power output at the cost of decreasing compression ratio and thermal efficiency),…

How is the useful heat used? I know some places have central heating, so the hot water is just piped throughout the city, but if not that, what would they do with it?

[deleted]

Re: Australia's first electric aircraft has begun test flights

#54

Post by Shivetya »

An interesting idea, my question is how high can you fly before temperatures lower the efficiency of the batteries? Let us assume a pressurized battery compartment to eliminate the air pressure issues, anyone familiar with the energy costs to keep cargo areas relatively stable? That might be equivalent for a battery compartment.

Re: Australia's first electric aircraft has begun test flights

#56

Post by alextheparrot »

seanmcdirmid wrote: post #47
pkolaczk wrote: post #21

Earlier quoted context omitted.

Typical coal power plants have practical electric efficiency 40% but total energy efficiency is 60-70%, because they produce electricity and useful heat . Also 40% is a theoretical (lab) value for a non turbocharged diesel engine - in practice most engines are operated out of their optimal range, they are turbocharged (a turbo increases power output at the cost of decreasing compression ratio and thermal efficiency),…

How is the useful heat used? I know some places have central heating, so the hot water is just piped throughout the city, but if not that, what would they do with it?

The term that the original poster didn’t include is “Cogeneration” [0]. Another use case would be desalination in areas without an adequate supply of freshwater.

[0] https://en.m.wikipedia.org/wiki/Cogeneration

Re: Australia's first electric aircraft has begun test flights

#57

Post by CardenB »

totalZero wrote: post #55

I look forward to the day when solar panels are efficient enough that an aircraft can appreciably recharge its batteries while gliding.

Does anyone know what the upper bound is on solar recharge rate vs energy needed to fly for a reasonably heavy aircraft?

Re: Australia's first electric aircraft has begun test flights

#58

Post by kylehotchkiss »

This is really exciting. I wonder if batteries will ever be able to power a 50 passenger aircraft, without having to extend the wings out too much to fit more batteries/lift for the extra weight.

I can't see the 15 hour, 400 passenger flight planes going with batteries in our lifetimes but it's cool to see things starting to go that way.

Re: Australia's first electric aircraft has begun test flights

#59

Post by cstrat »

totalZero wrote: post #55

I look forward to the day when solar panels are efficient enough that an aircraft can appreciably recharge its batteries while gliding.

That would be amazing. Flying above the clouds with unobstructed sun hitting the panels you would imagine should be possible one day.

Re: Australia's first electric aircraft has begun test flights

#60

Post by dogma1138 »

bobsil1 wrote: post #8
magicbuzz wrote: post #5

Article gives you the idea that it would be taking pax to Rottnest Island (a popular tourist destination) but it's only registered as a 'recreational' so the only ppl going to Rottnest would be pilots themselves or a non-paying pax. Payload is 200kg so that is basically two people and one suitcase. 30 minutes reserve might be enough for short hops but I've just finished reading various articles written over the years…

Tesla is driving (heh) battery energy density up.

Not really, also while Tesla does work on batteries it’s more Panasonic which makes he batteries for Tesla, LG chem and the likes that actually work on that.
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