Electric Airspeed Record.

[fatbutt]

Battery energy density may never achieve that of fossil fuels but what of other developments that we do or don't know about? The big point about this electric revolution we're witnessing is that once you move across to electric so many more options are available. Electricity can be generated and/ or stored in a multitude of ways and there is tech being developed in lots of different industries that will come to light in the next decade or so. What pushes this is demand; now that electric cars are are taking over everyone will see a change in terms of component size, cost and availability. I work in the marine sector and electric/ pilotless tankers are about to hit the seas. Large power generation and storage management will come as a consequence of that. And there is also the massive rise in R&D on wave and tidal generation that is leading to some very interesting short term/ cyclic energy storage approaches.

What gets developed in one industry will be repurposed in another. Have some faith!

[anonymous-user]

fatbutt said:

Max_Torque said:

fatbutt said:

. 20 years development will bring some serious changes in electrical tech.

And you know this how? The last 20 years in EV passenger cars (and i've worked with EV cars for that long!) hasn't actually brought any great change, other than the COST per kWh falling with mass production. Even crap 'lecy motors are 90% efficient (super trick, mega expensive ones like the ones i have designed for F1, which cost the best part of £100,000 for the components for each motor, are up to 98% efficient. ie "just" 8% better. Same with batteries. The biggest improvements in battery energy density have actually been through the packaging of the cells and support systems, and not actually from the chemistry of those cells themselves. Energy densities have risen from something like 150 to 250 W. h/kg over the last 15 years, whilst to make an full scale, long range electric airline feasible, we need something around 5,000 W.h/kg......

(Kerosene is ~12,000 W.h/kg btw)

Oh for crying out loud! Battery tech has massively changed in the last 7 or 8 years and is making significant advances year on year as the motor industry digs its heels in on the R&D. The batteries I used only 2 years ago are outclassed by what I can buy today. Axial flux electric motors, the core component behind the current viability of EVs have only been viable since 2009. A 75kW standard electric motor weighs 500Kg, and equivalent axial flux motor weighs 10Kg. IGBT tech is drastically different in terms of size and communications; compare a '98 invertor (size of a cabinet) to a '18 invertor (size of a briefcase).

https://jalopnik.com/the-fascinating-engineering-b...

https://insideevs.com/nissan-leaf-40-kwh-battery-d...

Head of BMW i division:

“At the time of the BMW i3, the capacity of batteries was still quite low, and so we tried to get every kilogram out of the car to reduce the amount of energy we needed [to power it]...But, with the improving energy capacity of batteries, you don’t need to look for the last 500 grams. Therefore, we look for the right balance of properties. Carbon fiber is still an extremely important material when it comes to passenger safety, for example, but you only use it in certain areas.”

2018 tech will be hopeless when compared to 2038 tech.

Can i just quote this for the Ph "man on the internet tells person who is an expert in their field how the things he works with, and has done for every day the last 25 years, actually work"..... ;-)

I'll not bother going through your mistakes and mis-truths (if you want i can, but it'll be long dull post).

[anonymous-user]

Talksteer said:

All the parts you describe are ancillary systems not megawatt scale motors and power electronics which must be optimised to much higher power to weight than for automotive applications.

This new project isn't a MW scale motor either (it's 3 x 200kW ones or, 3x 70Kw if you take the continuous rating, which is what those ratings are in the picture i posted of the normal planes electrical generation system)


Good luck with optimising everything to a high power to weight than automotive! Sure, OE automotive has a bit to give (not nearly as much as you might think, thanks too heavy optimisation these days, but take say the state of the art FormulaE battery pack (which i consulted on btw) it's already made of mostly carbon fibre (structurally) it already uses an extremely well mass optimised cooling and BMS system, it even uses non metallic bus bars (sorry i'm not at liberty to tell you what they are actually made from). FE batteries are also low volume and do things that would not be possible if you wanted to mass produce them (things like tooling access and fasteners etc are not optimised for build)

Sure, you could make it lighter, i'd guess if money was really no object, but there's no way you'd take off more than 3 to 4% by our reckoning.

[mcdjl]

Max_Torque said:

Can i just quote this for the Ph "man on the internet tells person who is an expert in their field how the things he works with, and has done for every day the last 25 years, actually work"..... ;-)

I'll not bother going through your mistakes and mis-truths (if you want i can, but it'll be long dull post).

From my side, please do, I'm an engineer geek so it'll be interesting. Reading between the lines of what the two of yo are saying your seem to be arguing slightly different things (eg size of inverter/ power density of batteries).
One thing thats interesting to me is that once we've gone elctric it appears to be relatively easy to change battery. This means that if a new chemistry becomes viable to replace li-ion/li-po etc then its a simpler move than from hydrocarbon in the first place.

[loudlashadjuster]

Talksteer said:

250 wh/kg battery packs will be available by the time (2022) that the first limited production electric regional aircraft are entering service.

For a new aircraft to be entering service in 2022, and using 787 or A380 development as a guide, such planes would probably have had to been announced publicly around 2013 or so, designs substantially finalised by 2016, procurement rounds would now be completed and manufacturing would already be in full swing in anticipation of first flight in the next 8-12 months.

Obviously none of this is happening.

And although those planes had troubled inceptions, they were not substantially different from pre-existing aircraft in many fundamental ways. The gestation, testing and regulatory phases for a brand new type of propulsion probably means even longer development timescales than the evolutionary 787/A380.

Talksteer said:

This means a practical range of about 900km or London to Berlin, this is enough to start the transition to electric flight.

With 1000wh/kg batteries we could basically go anywhere, you would need to change more than today but that would be relatively painless if the batteries were changed or procedures were simplified. We could boost the range to ~ 9000 km by having a very high ratio of battery to plane. At current development rates batteries would hit 1000wh/kg in 20 years time.

Painless? Perhaps...for the plane. How quickly can you safely put the required amount of electricity back into those massive batteries? Bear in mind turnaround costs $$$, airports only have so much space and infrastructure, and today's business is predicated on a 50-90 minute turnaround.

Using what I understand of your assumptions regarding battery energy density, a short-haul plane in the 737/A320 class of about 70 tonnes MTOW would be about 38.5 tonnes of battery.

At your assumed density of 450 Wh/kg needed for "virtually any flight in Europe or China" and, what, a 1,500 VDC system? that's a battery of about 11,550 Ah.

Let's shove 250 A into them. Hell, why not make it 500 A. That's more than double the current Tesla supercharger current at much higher voltage (no doubt some electrical engineer will be along to tell me that cables to transmit such power would be unmanageable, think this would require something like a 185 mm2 conductor, 15cm diameter!).

Regardless, a battery that large with that kind of charging will take about...28 hours to get to 100%. Double the charging current? Sorry, still 14 hours till the airport stops charging you for your parking slot and your fancy plane can start earning you money again.

These are hastily arrived-at figures and I may well have screwed something up, but even if I am off by an order of magnitude (and there is every chance , happy to be corrected) that's still way, waay off the current (lol) refuelling time. The whole air transport industry would have to be turned on its head to accommodate such changes.

And no no improvement in energy density or $/Wh can change the laws of physics, there would still be a need to move a lot of electrons hella quickly to make pure electric propulsion economically feasible, even if it is technically achievable.

I await the inevitable corrections

[Shakermaker]

loudlashadjuster said:

Painless? Perhaps...for the plane. How quickly can you safely put the required amount of electricity back into those massive batteries? Bear in mind turnaround costs $$$, airports only have so much space and infrastructure, and today's business is predicated on a 50-90 minute turnaround.

Using what I understand of your assumptions regarding battery energy density, a short-haul plane in the 737/A320 class of about 70 tonnes MTOW would be about 38.5 tonnes of battery.

At your assumed density of 450 Wh/kg needed for "virtually any flight in Europe or China" and, what, a 1,500 VDC system? that's a battery of about 11,550 Ah.

Let's shove 250 A into them. Hell, why not make it 500 A. That's more than double the current Tesla supercharger current at much higher voltage (no doubt some electrical engineer will be along to tell me that cables to transmit such power would be unmanageable, think this would require something like a 185 mm2 conductor, 15cm diameter!).

Regardless, a battery that large with that kind of charging will take about...28 hours to get to 100%. Double the charging current? Sorry, still 14 hours till the airport stops charging you for your parking slot and your fancy plane can start earning you money again.

These are hastily arrived-at figures and I may well have screwed something up, but even if I am off by an order of magnitude (and there is every chance , happy to be corrected) that's still way, waay off the current (lol) refuelling time. The whole air transport industry would have to be turned on its head to accommodate such changes.

And no no improvement in energy density or $/Wh can change the laws of physics, there would still be a need to move a lot of electrons hella quickly to make pure electric propulsion economically feasible, even if it is technically achievable.

Just to point out, you're being overly generous there for most 737/320 class aircraft where turnarounds are more likely 25-50 minutes in most cases. Even less time to recharge the batteries, especially considering all the other activities going on during that time period

[fatbutt]

Max_Torque said:

Can i just quote this for the Ph "man on the internet tells person who is an expert in their field how the things he works with, and has done for every day the last 25 years, actually work"..... ;-)

I'll not bother going through your mistakes and mis-truths (if you want i can, but it'll be long dull post).

Well, as an expert you're quite out of touch. I build these things too. You're just another 'man on the internet' as far as I can tell.

[Talksteer]

loudlashadjuster said:

And no no improvement in energy density or $/Wh can change the laws of physics, there would still be a need to move a lot of electrons hella quickly to make pure electric propulsion economically feasible, even if it is technically achievable.

I await the inevitable corrections

Fundamentally current automotive cells and their associated packs can charge at 0.5C or a full charge in 30 minutes. In practice this charge rate is usually only possible across the middle 70-80% of capacity so it is likely that those max ranges I quoted would be reduced commensurately.

You need enough conductor area to get max power and max charge rate is normally similar on a long range aircraft. Current EV packs manage to have enough conductor area in them to support rapid charging.

As for the plug, it will be massive, probably semi fixed and mounted on a robot arm. Eventually airports will need multiple GW power lines running into them with substations at each power outlet.

The question to ask is how much will this cost as a portion of a ticket?

While adding charging infrastructure to Heathrow would cost billions, it would last around 20 years and cost each passenger less than £5 a flight.

What is more electrical infrastructure in this case is relatively easy to scale, you can add much of it one gate at a time, you know when the planes are landing and how big they are.

[wst]

pingu393 said:

Perhaps, a catapult launch could help reduce the on-board energy store. It's a practical solution for small aircraft, but probably not for a 747 .

I have catapulted an English Electric plane (ironically, powered by petrol) with the assistance of about 7 other people on the catapult and a few more to hold the tail of the plane, and a lunatic in the seat... it is quite an unusual experience.

[loudlashadjuster]

Talksteer said:

Fundamentally current automotive cells and their associated packs can charge at 0.5C or a full charge in 30 minutes. In practice this charge rate is usually only possible across the middle 70-80% of capacity so it is likely that those max ranges I quoted would be reduced commensurately.

You need enough conductor area to get max power and max charge rate is normally similar on a long range aircraft. Current EV packs manage to have enough conductor area in them to support rapid charging.

Even assuming you can get enough energy into the system to support something like best-case EV charging like this though, surely at some point the mass of interconnecting harness and cooling (and heating?) infrastructure between the myriad cells starts to become a significant factor in the total mass of the 'battery'? Individual cells might only require a modest interconnect, but the main busbars will surely be chunky fellas to get all that juice to where it is needed? No point in running 18 AWG off a stick welder...

I mean it's not as if this will be a nice rectangular unit like in a car, presumably there will be a lot of stuffing cells wherever they can be squirrelled away in the wings etc. All cable and heat management is dead weight, all additional losses.

[fatbutt]

loudlashadjuster said:

Talksteer said:

Fundamentally current automotive cells and their associated packs can charge at 0.5C or a full charge in 30 minutes. In practice this charge rate is usually only possible across the middle 70-80% of capacity so it is likely that those max ranges I quoted would be reduced commensurately.

You need enough conductor area to get max power and max charge rate is normally similar on a long range aircraft. Current EV packs manage to have enough conductor area in them to support rapid charging.

Even assuming you can get enough energy into the system to support something like best-case EV charging like this though, surely at some point the mass of interconnecting harness and cooling (and heating?) infrastructure between the myriad cells starts to become a significant factor in the total mass of the 'battery'? Individual cells might only require a modest interconnect, but the main busbars will surely be chunky fellas to get all that juice to where it is needed? No point in running 18 AWG off a stick welder...

I mean it's not as if this will be a nice rectangular unit like in a car, presumably there will be a lot of stuffing cells wherever they can be squirrelled away in the wings etc. All cable and heat management is dead weight, all additional losses.

We got 3C out of these: https://www.xaltenergy.com/wp-content/uploads/2018...

[Talksteer]

Max_Torque said:

Talksteer said:

All the parts you describe are ancillary systems not megawatt scale motors and power electronics which must be optimised to much higher power to weight than for automotive applications.

This new project isn't a MW scale motor either (it's 3 x 200kW ones or, 3x 70Kw if you take the continuous rating, which is what those ratings are in the picture i posted of the normal planes electrical generation system) to


Good luck with optimising everything to a high power to weight than automotive! Sure, OE automotive has a bit to give (not nearly as much as you might think, thanks too heavy optimisation these days, but take say the state of the art FormulaE battery pack (which i consulted on btw) it's already made of mostly carbon fibre (structurally) it already uses an extremely well mass optimised cooling and BMS system, it even uses non metallic bus bars (sorry i'm not at liberty to tell you what they are actually made from). FE batteries are also low volume and do things that would not be possible if you wanted to mass produce them (things like tooling access and fasteners etc are not optimised for build)

Sure, you could make it lighter, i'd guess if money was really no object, but there's no way you'd take off more than 3 to 4% by our reckoning.

Power electronics and motors still have plenty of headroom. Integrating structure and electrical equipment we have barely scratched the surface.

As for batteries, I was mainly thinking about cell chemistries when aviation is a sector which is a major consumer ergo next decade. At this point I expect a major diversion in drivers for their batteries.

This is an approximation of where batteries are with 10 = the value at which returns become diminishing.

Property	Automotive	Aviation
Cost per KWh	5	8
Kg/KWh	7	2
Cycles to 85%	9	3

The price of batteries (to Tesla at least) would be cheap enough to make a massive impact on the cost of flying today anything better is merely a nice to have and won't change ticket prices much.

However for automotive there will be significant cost pressure until batteries reach ~ $25/kWh.

For automotive anything over 400wh/kg (pack) is a nice to have as it would bring a 100kwh pack down to 250kg. In aerospace we'd probably keep on researching till we hit 3000 and enabled a VTOL intercontinental supersonic electric jet!

Battery life is basically okay as early Tesla's are now 6 years old and holding up adequately. For aerospace we will want to work them make harder and while we will initially use them as consumables there will still be a strong drive to push life much further. Life is also secondary to power density.

Now I'm not ruling out that developments in this sector won't continue to hit all three parameters simultaneously for a while or that these are the only parameters.

This project is about walking before running, to date the number of high performance electric aircraft is less than you have fingers. To draw an analogy, what did Falcon 1 achieve in terms of pushing rocket technology forward Vs what it achieved in terms of growing industry capacity.

[smig12345]

Max_Torque said:

smig12345 said:

poing said:

ash73 said:

Batteries are heavy, so let's put them in an aeroplane. Stupid idea.

That's killed it, I doubt a single person on that project ever thought about that. Unless an electric parrot is heading this way.

I think this is a great project and there are so many commercial advantages to electric aircraft. As I understand it EasyJet are investing a fair amount into the concept. Something they pointed out, that I hadn't considered, is the idea of having more late night flights because they are currently restricted due to noise issues.

So far they are only looking at short distances but the kind that are perfect for the UK. Sounds similar to the motoring world where they talk a lot about the final mile but with the big distance stuff using a different technology.

I know these kind of projects will have their doubters but there were people saying an aircraft would never cross the Atlantic not too many years ago.

Exactly! It wasn't too long ago people were saying it was impossible to get to the Moon, it was impossible to travel faster than the speed of sound, if you travelled over 60 mph on a train the air would be sucked out of your lungs, etc, etc.

Like it or not the future is electric. I think it's great British companies like Rolls Royce, Yasa, Electroflight, etc are doing something like this, it shows British engineering in a positive light around the World. I think we as a country should invest heavily in this so that when it is common place in years to come we will be leaders in the World market. It is going to come on in leaps and bounds in the future. We don't have many industries left in the UK, we should invest heavily in this high tech industry of the future.

well that's all super isn't it, Thanks god, that's it all fixed and sorted. Lets just get on with making 'lecy airlines now then eh.

Oh, wait, we can't because the laws of physics prevent it. And that's the rub, loads of people who don't understand engineering and physics can shout all they like but as Scotty so rightly said on many an occasion "you canne change the laws of physics captain".....

All those things you mention, crossing the atlantic, breaking the sound barrier, getting to the moon or even going faster than 60 mph on a train, what do they have in common? Have a think? Well, i'll tell you, despite none of them breaking the laws of physics, none of them were achieved until certain key technologies were mature enough to support than endeavour. Be that external combustion engines with sufficient thermal efficiency to drive a heavy, draggy stream engine and carriages to over 60 mph, internal combustion engines reliable and powerful enough to fly across the atlantic, the development of electronic control systems, ultra high performance turbopumps, cryogenic fuels storage, handling and combustion systems to provide sufficient thrust to get juust enough mass to the moon and back to support a manned operation, or the understanding or transonic compression effects on control surfaces and the impact of aerothermal heating to allow an aircraft to punch through the sound "Barrier". In each case, there was no fundamental physical barrier to the successful achievement of those tasks, just an incremental, stepwise maturing of critical tech.

Today, battery electric airliners are not feasible. Sorry, that's just the way it is. In maybe 25 or 50 years we may have a technology singularity that provides a "shortcut" to a viable,workable solution, or we may not. That could of course happen tomorrow. And there's the rub, we just don't know.

As i have explained in my previous post on this thread, the challenges are well understood (max L/D max PrpEff, max EnergyDensity). Nothing is that new, that novel, or mis-understood, we are simple too far away from a viable solution with current technology.

You come across as a bit of a tw@t. The point is technology doesn't stand still dummy, this technology is going to advance in leaps and bounds.

[IforB]

Max_Torque said:

Can i just quote this for the Ph "man on the internet tells person who is an expert in their field how the things he works with, and has done for every day the last 25 years, actually work"..... ;-)

I'll not bother going through your mistakes and mis-truths (if you want i can, but it'll be long dull post).

I'm going to quote this as an example of PH"man on the internet tells everyone that he knows better than everyone else because he has a bit of knowledge in something similar, but is completely missing the point of the project."

Let's be clear here, from an aviation standpoint (something this expert knows a lot more about than you - see 2 can play that game!) this is an interesting project and is very, very far from the pointless waste of time that you seem to be trying to make it out to be.

As someone who would actually buy one of these things if it got through certification and made it to market, then from my perspective, it helps answer a lot of issues that have been troubling the aviation world for a long time. Namely noise and pollution.

Is this project going to lead to an all electric airliner in the next 5 years? Of course not and to even suggest that is the point is absolute balderdash. This is the start of a new and very exciting development path for aircraft. I don't care if the technology in the batteries is well understood or not. That is not the point. They are not well understood in the context of them being the primary power source for a certificated, public transport category, manned aircraft.

That is the challenge and the development path for useful all electric flight does not have to go directly to airliners, there is a whole industry out there away from the big stuff who are watching this keenly.

So do pipe down a bit old boy. You are making a mess of this thread that could be very interesting with your constant stream of criticism that entirely misses the point.

As a great man once said. "Why don't you knock it off with them negative waves."

Edited by IforB on Tuesday 8th January 16:56

[mcdjl]

IforB said:

That is the challenge and the development path for useful all electric flight does not have to go directly to airliners, there is a whole industry out there away from the big stuff who are watching this keenly.

A quick search suggests that Airbus have had just under 19,000 aircraft ordered. On the other hand 44,000 Cessna 172s have been built. Powering the next generation of those would be quite a business.

[911newbie]

Jesus, what happened to this thread ?

Why all the toxicity between posters ?
Can we not behave like adults and have an interesting discussion ? Max Torque for example - you clearly have some interesting and informed points of view but your tone is abusive and you argue for no good reason.

I was interested in this discussion, but this has turned me right off.

Just remember everyone that even though we cannot see each other's faces, and we're anonymous, that being a grown up and keeping it all nice and civil in the end makes for a more readable, interesting and engaging forum.

Better if all the stupid internet-point scoring stayed in the Politics thread to my mind.

Edited by 911newbie on Tuesday 8th January 17:10

[anonymous-user]

Have you actually read any of my posts Ifob? Way back on page 1 or 2 someone claimed i was saying the project was a "waste of time" to which i wrote:

max_torque said:

I have never said that, and i never will. The project will be a lot of fun, it will keep some clever engineers in a job, provide and interesting topic for learning for everyone, provide RR with many column inches and excellent PR. It may even inspire some young kids to become engineers.

Does that sound negative to you? What i also said, and seems to be causing people to get in a froth (people who seem to post numbers that don't actually add up] is that this project has little real overlap with actually getting to an electric airliner. RR are using this falicy as a way to get (government, ie, paid for by us tax payers) funding. I wish them the best, i'm sure they will hit their speed targets and get lots of great publicity for how brilliant we are at "British engineering" and all that pomp, but really, this project is simply to technologically disconnected from the real, fundamental challengers involved with moving mainstream passenger aircraft over to battery electric power.

[anonymous-user]

fatbutt said:

Max_Torque said:

Can i just quote this for the Ph "man on the internet tells person who is an expert in their field how the things he works with, and has done for every day the last 25 years, actually work"..... ;-)

I'll not bother going through your mistakes and mis-truths (if you want i can, but it'll be long dull post).

Well, as an expert you're quite out of touch. I build these things too. You're just another 'man on the internet' as far as I can tell.

Ok, fair enough, So, what's on your CV?

I have the fastest electric lap of the N'ring, the fastest electric car up Pikes Peak, the fastest hybrid supercar, and 3 production high performance EVs on mine?

[Flying Phil]

.....Meanwhile, can we get back to the aeroplane - and do we know when it will be ready to take to the air?

[anonymous-user]

Talksteer said:

For automotive anything over 400wh/kg (pack) is a nice to have as it would bring a 100kwh pack down to 250kg. In aerospace we'd probably keep on researching till we hit 3000 and enabled a VTOL intercontinental supersonic electric jet!

Ok, lets run with this> Pretend it's Dragons Den, show me your numbers to support 3kW.h/kg being sufficient for a VTOL supersonic 'lecy jet?




So you don't think i'm deliberately being hard or obstructive (i'm not), here's my analysis, please correct where you disagree:

(i've pulled figures off the net, so they may not be absolutely correct, figures are from here: f35_specs )


Intercontinental; London to New York (Europe to America) is about 3,400 miles ~ 5,400 km

VTOL Supersonic jet = F35B

Dry Mass: 10,660 kg
Total Internal Fuel Load: 6,045 kg
Range: ~2,000 Km (this is classified as far as i can tell, and it is not clear under what loading conditions the 2,000 km figure is achieved)
Crew: 1 (pilot)
Max Payload: 4,990 kg



Jet fuel (Kerosene) has a (bare) energy density of 12,000 W.h/kg. That means total available energy for this plane of 72.5 MW.h
which gets this single seater jet, halfway across the Atlantic. (call it "semi-intercontinental shall we....)


You say 3kW.hr/kg is sufficient, well for the same energy as currently stored in the fuel in a F35B, that means a battery weight of 24,180 Kg. This quite litterally means the aircraft couldn't leave the ground! Those 24 tonnes of batteries weigh more than the entire airframe,pilot, fuel and max payload put together.......