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    •  
      CommentAuthorfostertom
    • CommentTimeSep 27th 2017
     
    https://www.theguardian.com/business/2017/sep/27/easyjet-electric-planes-wright-electric-flights

    "The airline said it was the next step in making the airline less harmful for the environment, after cutting carbon emissions per passenger kilometre by 31% between 2000 and 2016."

    “You’re seeing cities and countries starting to talk about banning diesel combustion engines. That would have been unthinkable just a short time ago,” Duffy said. As technology moves on, attitudes shift, ambitions change and you see opportunities you didn’t see.”
    • CommentAuthortony
    • CommentTimeSep 27th 2017
     
    Power density problems will preclude batteries for airliners, possibly hydrogen could work
    •  
      CommentAuthordjh
    • CommentTimeSep 27th 2017
     
    "Wright Electric explained that the new batteries it is hoping to invent"

    Courtesy https://www.navitron.org.uk/forum/index.php/topic,28864.0.html and http://www.bbc.co.uk/news/business-41404039
    •  
      CommentAuthorSteamyTea
    • CommentTimeSep 27th 2017
     
    Posted By: djhhoping to invent
    I am hoping to invent a special box.
    When people talk bollocks, all I will hear is Bob Dylan's 'Idiot Wind'.
  1.  
    More wishful thinking/GreenWash. Honestly, its' fine to expand airport capacity now because we will be flying electric planes by the time it's online. Oh, the tech doesn't work? We'll just keep flying the same old planes until it does - theres no point not using all this runway capacity we've just built
    •  
      CommentAuthorfostertom
    • CommentTimeSep 28th 2017
     
    If you guys just see a futuristic forum as an opportunity to display Grumpy Old Men credentials, that's ... boring - as well as, more likely than not, wrong.
    • CommentAuthorMarkyP
    • CommentTimeSep 28th 2017
     
    billions of dollars going into R&D on elec and battery tech. I find it hard to see that leading to nothing over the next couple of decades. It's easy to shoot holes in the future state vision based on current constraints. But I dont understand what's wrong with a bit of optimism, and at least consideration and discussion of potential future states based on yet to happen tech improvements.

    The times, they are a-changin'
    •  
      CommentAuthorSteamyTea
    • CommentTimeSep 28th 2017 edited
     
    Posted By: fostertommore likely than not, wrong.


    Posted By: MarkyPbillions of dollars going into R&D on elec and battery tech.


    The other thing I am going to invent is a new periodic table.
    It will have some new particles in it, or new uses for old particles.
    Maybe a new atom that is lighter than hydrogen and more electrons than uranium would be useful.

    Kerosene has an energy density of 42.8 MJ/kg
    The best nickel metal hydride has an energy density of 0.237 MJ/kg
    So there needs to be, before different engine/motor efficiencies are taken into account, an improvement of 170.
    I just can't see that happening.

    (a cheese sandwich has better energy storage that a battery)
    • CommentAuthorgravelld
    • CommentTimeSep 28th 2017
     
    Well lithium would at least double it? But point taken.
    • CommentAuthorMarkyP
    • CommentTimeSep 28th 2017
     
    I like "new uses for old particles". Was that a serious reference to what is the basis for much research hidden in the sarcasm? Or was it accidental irony? Actually, it doesnt matter which, it's funny either way.

    we could talk more about whether future battery tech must match kerosene energy density to viable. We could talk about potential energy density of alternative chemistry based battery tech like metal air. We could talk about changing material and transport tech and how all of these might offer a different future state. It may or may not happen, but it might have been interesting to talk about it. It's a shame, I've been a member here for I think 5 years and a reader/lurker for as many again, it seemed like in the past there was a lot more discussion for discussion's sake.
    •  
      CommentAuthorfostertom
    • CommentTimeSep 28th 2017
     
    5yrs? Go back 15 (I think it was) and you'd find an atmosphere of actual greenie ideological enthusiasm.
    Funny that the faster that ideology becomes reality, the more expert utilitarian scepticism settles into GBF.
    •  
      CommentAuthorSteamyTea
    • CommentTimeSep 28th 2017
     
    Posted By: MarkyPwe could talk more about whether future battery tech must match kerosene energy density to viable
    Yes we can talk more about this.
    As electric motors are more efficient than combustion engines, there is no need for total parity.
    Let us say that a turbine can effectively use 15% of the available energy in the fuel (let us not get into power delivery yet).
    And let us say that an electric motor can use 90% of the energy stored in the batteries.

    15% of 42.8 MJ is 6.42 MJ/kg for a turbine.
    90% of 0.237 MJ/kg is 0.213 MJ/kg for an electric motor.
    Or about 3%.
    So battery energy density would have to increase 30 fold to match current technology.

    That magic atom of hopium would need lots of spare electrons, 29 extra ones, and they would all have to be free electrons, not in a shell with other electrons.
    And it would still need the same number (3) of protons and neutrons to keep the mass down.

    So there was sarcasm and irony in my particle statesmen.

    The reason that there is less decent debate these days is many fold and goes back about 3 or 4 years when a number of active members were moved on. So nothing to do with expert utilitarian scepticism.
    • CommentAuthormarktime
    • CommentTimeSep 28th 2017
     
    +1
    •  
      CommentAuthorfostertom
    • CommentTimeSep 29th 2017
     
    Say that shortfall factor of 30 does reduce to 15 or even 10, with development.
    Then note that kerosene is the do-everything fuel whose energy density has to be good enough for fast huge intercontinental planes.
    Compare with slowish small short-range propellor planes - what lower energy density would be sufficient?
    What virtuous circles (like low weight requires lower power and storage which means yet lower weight which means ... and so on) would make the comparison better than linear/pro rata?
    • CommentAuthorMarkyP
    • CommentTimeSep 29th 2017 edited
     
    Posted By: SteamyTea
    So there was sarcasm and irony in my particle statesmen.



    in which case the word witty rather than funny would have been perhaps fairer in my previous reply.

    I think I read variously that metal-air offers a potential 10 fold increase in energy density. Agreed theoretical potential is one thing, realising it quite another. But my point about the R&D money is that so much weight is being thrown at research to transform battery tech, it feels like a breakthrough is more a question of when rather than if. I find it hard to beleive than with li-ion, we've reached peak storage potential. Whether EasyJet are being shrewd or indulging in an expensive folly, only time will tell. But as a short haul operator, it's a very sound business move to put up some risk capital to get involved in something that could transform the markets they operate in over the next couple of decades.
    •  
      CommentAuthorSteamyTea
    • CommentTimeSep 29th 2017
     
    Not sure Tom
    You can work it out, I am enjoying myself too much painting my kitchen.

    I fail to see how the energy density can improve much more as there are fundamental physical limits.
    • CommentAuthorSimon Still
    • CommentTimeSep 29th 2017 edited
     
    <blockquote><cite>Posted By: fostertom</cite>If you guys just see a futuristic forum as an opportunity to display Grumpy Old Men credentials, that's ... boring - as well as, more likely than not, wrong.</blockquote>

    Nearly all press stories are now little more than rewritten Press Releases with the journalists writing them unlikely to have any scientific knowledge or the time to challenge any of the assertions being made. there's knowlege and expertise on this forum so I find the flagging up of stories like this one without any critical review of the evidence or any degree of skepticism about the claims made or the motives of those who issued the press release to be disappointing.

    When discussion is about what to install in a build - types of insulation for example - there is debate about the strengths and weaknesses backed up with data. There has been a solid debunking (or at least attempt to understand the nature) of multi-foil insulation. I find it strange that someone would republish a story like that on here without some evaluation of the probablity of it being true.
  2.  
    Not least
    ""The airline said it was the next step in making the airline less harmful for the environment, after cutting carbon emissions per passenger kilometre by 31% between 2000 and 2016."

    31% reduction in emissions per passenger over 16 years? That sounds great doesn't it?

    Sure, until you realise that global passenger kilometres increased by 8% in 2016 alone (and that's pretty consistent looking back apart from a one off negative 8% in 2009. Growth in traffic is massively outpacing gains in efficiency.
    http://www.iata.org/whatwedo/Documents/economics/passenger-analysis-jun-2017.pdf

    Global air passengers forecast to double over next 20 years
    http://www.iata.org/pressroom/pr/Pages/2016-10-18-02.aspx
    • CommentAuthorgravelld
    • CommentTimeSep 29th 2017 edited
     
    The other thing is that the important thing is: why is the energy used, where does the requirement come from? It comes from the need for transport, and the requirement to be able to reach destinations world wide in short time spans.

    To this end, concentrating on jet planes may be a non starter, because technology develops in the meantime... https://www.youtube.com/watch?v=zqE-ultsWt0

    How many eneloops to power that?
  3.  
    Posted By: Simon Still31% reduction in emissions per passenger over 16 years? That sounds great doesn't it?

    Sure, until you realise that global passenger kilometres increased by 8% in 2016 alone (and that's pretty consistent looking back apart from a one off negative 8% in 2009. Growth in traffic is massively outpacing gains in efficiency.
    http://www.iata.org/whatwedo/Documents/economics/passenger-analysis-jun-2017.pdf" rel="nofollow" >http://www.iata.org/whatwedo/Documents/economics/passenger-analysis-jun-2017.pdf

    Global air passengers forecast to double over next 20 years
    http://www.iata.org/pressroom/pr/Pages/2016-10-18-02.aspx" rel="nofollow" >http://www.iata.org/pressroom/pr/Pages/2016-10-18-02.aspx


    The 31% reduction in emissions and the increase in global passenger kilometres are totally independent of each other - except that perhaps the 31% reduction also produced efficiencies that allowed cheaper fares so could you say the 31% reduction encouraged the increase in passenger kilometres by giving cheaper fares.
    • CommentAuthorMarkyP
    • CommentTimeSep 29th 2017 edited
     
    it's isnt just the energy needed to launch, you've got to start worrying about getting hit by nuggets of titanium travelling at 2 kilometers per second while you are up there.

    https://www.theguardian.com/science/across-the-universe/2017/apr/21/space-debris-must-be-removed-from-orbit-says-european-space-agency
    •  
      CommentAuthorfostertom
    • CommentTimeSep 29th 2017 edited
     
    Posted By: Simon Stilldebate about the strengths and weaknesses
    Fair enough - scepticism is part of that - except that it's only about weaknesses and habitual, therefore the counterpart of credulous optimism!
    Posted By: Simon Still... backed up with data ... I find it strange that someone would republish a story like that on here without some evaluation of the probablity of it being true.
    That's too high a bar for a freewheeling, instant-feedback forum - would be deadening if obeyed.
    Posted By: Simon StillThere has been a solid debunking (or at least attempt to understand the nature) of multi-foil insulation.
    That was my pet cause - and to this day, no engagement on GBF with the model that I offered several times of how radiant transfer becomes dominant during conditions of dynamic change in temp distribution (i.e. in real life nearly always) - which would explain MF's moderately unexplained success, and which could inspire a really effective application of the principle if reconfigured. So much for 'understand the nature'.
    •  
      CommentAuthorSteamyTea
    • CommentTimeSep 29th 2017
     
    Posted By: fostertomFair enough - scepticism is part of that - except that it's only about weaknesses and habitual, therefore the counterpart of credulous optimism!
    Often backed up with knowledge.


    Posted By: fostertomThat's too high a bar for a freewheeling, instant-feedback forum - would be deadening if obeyed.
    But you expect others to do the hard work for you, then you dismiss the findings with ridiculous counter claims.


    Posted By: fostertomwhich would explain MF's moderately unexplained success
    FFS, if it was so great and really worked, we would be using it.
    You often like a lone voice that goes against the grain. But when I dismissed low temperature radiant heating benefits, I get no supporters.
    And yet again, if it was so brilliant, we would all have surfaces a couple of degrees warmer to work as out heating systems, but cold air in the house.

    Stop this nonsense now.
  4.  
    Posted By: MarkyP But my point about the R&D money is that so much weight is being thrown at research to transform battery tech, it feels like a breakthrough is more a question of when rather than if.


    Hi Mark, I hope battery technology is transformed, but a lot of R&D money has been put into Nuclear Fusion Reactors for quite some time, without success yet.
    •  
      CommentAuthorfostertom
    • CommentTimeSep 29th 2017 edited
     
    Posted By: SteamyTeayou expect others to do the hard work for you ...
    others better suited than me, who are more than willing
    Posted By: SteamyTeathen you dismiss the findings with ridiculous counter claims
    no, often enough I concede, other times keep an idea alive because not conclusive IMO
    Posted By: SteamyTeaYou often like a lone voice that goes against the grain
    true
    Posted By: SteamyTeabut when I dismissed low temperature radiant heating benefits, I get no supporters
    I engaged with you about that, specified exactly the fallacy as I saw it but you blanked it! Strangely, it's quite connected with the MF issue.
    Posted By: SteamyTeaif it was so brilliant, we would all have surfaces a couple of degrees warmer to work as out heating systems, but cold air in the house
    that is exactly what happens, in a scheme we built to exactly that principle.

    How many degrees warmer depends upon the heat demand; if near-PH as this one was, the large wall emitters are about 1K warmer, with supreme comfort at a fresh, unstuffy air temp about 18C - because the radiant component is so unusually high.

    Note that the 'target' temp is not body (skin) temp but outer surface of clothing temp.
    The 'heating' doesn't have to be warmer than skin temp, because it's not heating the body, but regulating its rate of loss, as all our bodies do all the time, otherwise we'd pop!
    • CommentAuthorMarkyP
    • CommentTimeSep 29th 2017
     
    perhaps my optimism is mis-placed, Peter. my wife would argue that my ability to assess and forecast future outcomes is completely flawed given the number of project deadlines which I've missed
    • CommentAuthorSimon Still
    • CommentTimeSep 29th 2017 edited
     
    Posted By: SteamyTeaBut you expect others to do the hard work for you, then you dismiss the findings with ridiculous counter claims.


    My feelings exactly. I'm sure you're smarter than that so it feels like the behaviour of a troll

    Posted By: fostertomwhich would explain MF's moderately unexplained success


    The only places I know that it's been used were in loft conversions in victorian houses, and while loft conversions with PIR insulation result in cosy warm attics (and better performance for the house as a whole) the people who had it installed complained their attic rooms were cold. Pure anecdata so nothing to base a decision on obviously.
    • CommentAuthorMarkyP
    • CommentTimeSep 29th 2017
     
    Posted By: Simon Still
    The only places I know that it's been used were in loft conversions in victorian houses, and while loft conversions with PIR insulation result in cosy warm attics (and better performance for the house as a whole) the people who had it installed complained their attic rooms were cold. Pure anecdata so nothing to base a decision on obviously.


    I think you were complaining earlier about a lack of "critical review of the evidence" and opinions needing to be "backed up by data". And then in another recent thread I recall complaint about lack of citation of sources. And here we have a comment based on reports that Trevor from down the pub has loft conversion that feels a bit cold?
    •  
      CommentAuthorfostertom
    • CommentTimeSep 29th 2017
     
    I said
    Posted By: fostertomwhich would explain MF's moderately unexplained success ...
    which doesn't mean that MF works all that well - but much better than conventional theory and hot-box testing predicts - thus 'moderately unexplained'.
    Posted By: fostertom... which could inspire a really effective application of the principle if reconfigured.
    i.e. if the actual physics were open-mindedly investigated (rather than shamefully rubbished by NPL's tame scientists defending their conventional wisdom and paymasters' interests) a re-conceived product (i.e. not MF as we know it) could be fantastic.
  5.  
    Posted By: SteamyTea
    Posted By: MarkyPwe could talk more about whether future battery tech must match kerosene energy density to viable
    Yes we can talk more about this.
    As electric motors are more efficient than combustion engines, there is no need for total parity.
    Let us say that a turbine can effectively use 15% of the available energy in the fuel (let us not get into power delivery yet).
    And let us say that an electric motor can use 90% of the energy stored in the batteries.

    15% of 42.8 MJ is 6.42 MJ/kg for a turbine.
    90% of 0.237 MJ/kg is 0.213 MJ/kg for an electric motor.
    Or about 3%.
    So battery energy density would have to increase 30 fold to match current technology.

    That magic atom of hopium would need lots of spare electrons, 29 extra ones, and they would all have to be free electrons, not in a shell with other electrons.
    And it would still need the same number (3) of protons and neutrons to keep the mass down.

    So there was sarcasm and irony in my particle statesmen.

    The reason that there is less decent debate these days is many fold and goes back about 3 or 4 years when a number of active members were moved on. So nothing to do with expert utilitarian scepticism.


    Its rubbish like this which has reduced the amount of decent debate on the forum. Instead of writing this sort of negative bull poo why dont you actually do some net surfing and actually see what electric aircraft are already flying. You might even be surprised that an electric plane has already been approved to carry commercial passengers. But then why ruin a negative comment.

    Next you will be saying you cannot power a plane with a steam engine.
   
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