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    • CommentAuthorSprocket
    • CommentTimeJun 8th 2012
     
    That was one of the headlines on a regular news email Ireceived this morning.

    BUT the original email was from Elektor. The article the email links is a bit short on detail:-
    http://www.elektor.com/news/store-thermal-energy-forever.2182261.lynkx

    So I followed the link in that article to another at techthefuture:-
    http://www.techthefuture.com/energy/zeolite-stores-thermal-energy-for-unlimited-amount-of-time
    Still short on detail so I tried to follow their link to Fraunhofer Institute.
    But that link doesn't seem to work :-/

    But then I found this
    http://www.fraunhofer.de/en/press/research-news/2012/june/compact-and-flexible-thermal-storage.html
    and it has a link to a pdf.

    Even that is still frustratingly short on detail though.
    Is it just a very slow news week or is there something more to this that might be worth getting excited about?

    PS: I think we might have done the subject to death in another thread recently but this is supposedly engineering news, not product related yet, so I thought it might be worth a new thread/outlook. Briefly considered posting it in renewables or heating/cooling topics but decided it was perhaps more general interest (if there is anything to it).
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 8th 2012 edited
     
    Posted By: Sprocketif there is anything to it

    Second Law of Thermodynamics states not (the forever bit).

    http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8946

    Also it is worth remembering that there is a distinct difference between energy density and power density. Zeolites seem to have a good energy density, not sure of the power density.
  1.  
    I have been using a similar system for drying woodchip using activated alumina and solar. Surprised it is considered news as the technology has been around for a long time and is used in dehumidifiers.
    • CommentAuthorSprocket
    • CommentTimeJun 8th 2012
     
    >Surprised it is considered news

    I'm even more surprised it was considered ELECTRONICS news.

    Still, being able to use it conveniently and easily for domestic heat staorage as was discussed in that other thread (thanks for linking ST, I should have done that in the first post) would perhaps be a big deal if the numbers and costs worked out. The Fraunhofer summary does say they are now focussing on the engineering/construction problems that go with plant equipment for a practical application of this.

    In the other thread I seem to remember the material was alumina, not Zeolite (though Zeolite was discussed) and that Zeolite would be rather more expensive.

    I wonder if this "research" is just that or whether they really do have evidence it could lead to a practical affordable product. There are suggestions that the workable scale is slightly larger than domestic.
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 8th 2012
     
    As with most things, you have to exhaust the alternatives first before you start developing a new line.
    If there are easier/cheaper/better ways of achieving an aim, then tend to be used.
    I suspect that most of us on here could go into a strangers house and cut their energy usage by 20%.
    Armed with £100, probably by 30%.
    £10,000 and probably 70% (though they would not like the lifestyle much)
    • CommentAuthorEd Davies
    • CommentTimeJun 8th 2012 edited
     
    Posted By: SteamyTeaSecond Law of Thermodynamics states not (the forever bit).

    Nothing's forever but the Second Law in no way indicates that this system can't store energy for useful (e.g., inter-seasonal) periods of time with very little insulation. Keeping water vapour out of a box for a while is a lot easier than keeping heat in.

    It's interesting that a separate and very credible institution is working on this but, other than that and as Sprocket says, there's so little detail here that it's not really very useful. The fact that they claim to have cycled the stuff a lot seems encouraging, though.

    Posted By: SprocketThere are suggestions that the workable scale is slightly larger than domestic.

    Again, it's difficult to tell, but it sounds like their focus is on larger scale but that may just be because they think that's where it'd be easier to introduce. Adding a new box in a local CHP plant sounds like a quicker fix than re-engineering inter-seasonal stores in houses when few are designed to use them, anyway. The current domestic market would only be a few nutty new builders.
  2.  
    Posted By: Sprocket>

    I wonder if this "research" is just that or whether they really do have evidence it could lead to a practical affordable product. There are suggestions that the workable scale is slightly larger than domestic.


    Its certainly practical if combined with a hvac system
  3.  
    A bit left-base here. but just to put into context how much energy is stored in the phase change of water vapour to liquid ...

    last week, we had a thunderstorm in Montreal that dropped 80mm rain in 40 minutes (that's a whole month's worth - it was so heavy that manhole covers were blown off as geysers erupted ... and a hilly street near me had its asphalt stripped by the torrent of a river that formed). I did a few back of the envelope calculations and discovered the energy required to condense 80mm of rain over and area of 1 square kilometer is equivalent to 42,000 tons of TNT - so that's equivalent to 3 Hiroshima-sized bomb's worth of energy over each square kilometer. Quite sobering really! Put another way, each square meter received the equivalent of 73kW power output over that 40 minute period.

    Paul in Montreal.
    •  
      CommentAuthorDamonHD
    • CommentTimeJun 8th 2012 edited
     
    Hmm, that definitely counts as "intermittent"...

    I experienced a downpour of that ilk once in Malta ... while driving to the airport for a flight home. Had to take an interesting 'alternative' random-walk over hills since the lower roads were flash-flooded, and drive like billy-o across up-down roads to get through the foot-high (or more) torrents without stalling the engine...

    Rgds

    Damon
  4.  
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 9th 2012
     
    Puts things into perspective when one storm can release nearly 50 kWh.m^-2m you can see why the climate change sceptics get so worked up about the seemingly small impact that humans make.
    Now if a house uses 100 kWh.m^-2.y^-1, that is 6 months worth of domestic use released in 2/3rd of an hour. Suspect that not much of the house would be left.
    • CommentAuthorJoiner
    • CommentTimeJun 9th 2012
     
    Had to stop in the middle of our parking area because the rain was so heavy I couldn't see out of any of the van's windows and the noise completely drowned-out the radio. It was as if a vast bucket of water had been emptied over me. It started in a matter of a split-second and ended as quick.

    For the briefest of moments I almost started to believe in God. :shocked:
    • CommentAuthorowlman
    • CommentTimeJun 9th 2012
     
    Posted By: SteamyTea.......... you can see why the climate change sceptics get so worked up about the seemingly small impact that humans make.

    Surely ST with such powerful forces, that's exactly the point WHY "seemingly small" anthropogenic impact has to be taken seriously.
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 9th 2012
     
    I know that, the accumulative affect can often seem larger than the sum of the parts. But Climate sceptics don't seem to get it.
    • CommentAuthorEd Davies
    • CommentTimeJun 9th 2012
     
    Effect. :tongue:

    It's amazing how many people there were in Montreal who so desperately needed to get somewhere right then that they were willing to risk wrecking their car engines and possibly blocking a junction likely to be needed by the emergency services rather than just wait an hour or two.

    Or is it that they are so psychologically disconnected from the world around them by their urban existence that they simply can't conceive of having to adjust to circumstances a bit? I think it's this and a larger scale version of this mindset is why so many are climate sceptics.
    • CommentAuthorJoiner
    • CommentTimeJun 9th 2012
     
    :bigsmile: Is grumpiness contagious? Was it blown across the country by those gales from the south-west? :wink:
    • CommentAuthorowlman
    • CommentTimeJun 9th 2012
     
    Grumpiness is good for you, so they say, it makes you think more clearly.

    "Victor"
    • CommentAuthorJoiner
    • CommentTimeJun 9th 2012
     
    Makes other people think more clearly, you mean. :wink: They're afraid to open their mouth! :neutral:
    • CommentAuthorCWatters
    • CommentTimeJun 9th 2012
     
    One of the links Sprocket posted says...

    "When water comes into contact with zeolite it is bound to its surface by means of a chemical reaction which generates heat. Reversely, when heat is applied the water is removed from the surface, generating large amounts of steam."

    So it appears the energy is stored in a reversible chemical reaction of some sort. Ok so there might not be losses while the energy is "stored" but there will be some lost in the process of charging/discharging the store.
    • CommentAuthorEd Davies
    • CommentTimeJun 9th 2012
     
    As Sprocket said in the first post, we've already done this one to death. Might as well have a link to the remains, though:

    http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=8946&page=1
    • CommentAuthordjh
    • CommentTimeJun 11th 2012
     
    Posted By: Paul in Montreallast week, we had a thunderstorm in Montreal that dropped 80mm rain in 40 minutes (that's a whole month's worth - it was so heavy that manhole covers were blown off as geysers erupted ... and a hilly street near me had its asphalt stripped by the torrent of a river that formed). I did a few back of the envelope calculations and discovered the energy required to condense 80mm of rain over and area of 1 square kilometer is equivalent to 42,000 tons of TNT - so that's equivalent to 3 Hiroshima-sized bomb's worth of energy over each square kilometer. Quite sobering really! Put another way, each square meter received the equivalent of 73kW power output over that 40 minute period.

    I'm confused about that. I agree that condensing the water releases thermal energy. I don't see how that has any effect on the ground. The energy released by the rain hitting the ground is its kinetic energy, converted from the gravitational potential energy by falling from a height. The heat from condensation just means you got rain instead of hail, surely? (The heat will also affect the weather system itself)
  5.  
    Posted By: djhI'm confused about that. I agree that condensing the water releases thermal energy. I don't see how that has any effect on the ground.


    It doesn't :) I was just impressed by the energy exchanges required to create so much liquid water in such short time. Probably of more interest is that the SBCAPE (Surface-Based Convective Available Potential Energy) values were in the range 2500-3000J/Kg that day - these are extremely high values. A cubic metre of air is about 1kg so this gives an idea of the energies involved in that storm!

    I wasn't suggesting there as a 73kW flux to ground per square metre - just my figures were intended to visualize how much energy was involved above each of those square metres to make that rainfall in the first place!

    Paul in Montreal.

    ps I'd often heard that a thunderstorm is equivalent to several atomic bombs - my back-of-the-envelope calculations confirmed that this is the order of magnitude of energy involved in such a storm
    • CommentAuthordjh
    • CommentTimeJun 11th 2012
     
    Posted By: Paul in Montrealhow much energy was involved above each of those square metres to make that rainfall in the first place!

    Well, the energy isn't needed to make the rainfall. The energy is RELEASED when the rainfall is made. Making rain is exothermic.
  6.  
    Posted By: djhWell, the energy isn't needed to make the rainfall. The energy is RELEASED when the rainfall is made. Making rain is exothermic.


    True. but that much energy was required to evaporate the water in the first place :)
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 11th 2012 edited
     
    Posted By: Paul in MontrealTrue. but that much energy was required to evaporate the water in the first place :)

    Tends to be a more gradual process over several weeks though.
    Not sure where Montreal's rain comes from, ours is from the Gulf of Mexico/Caribbean, you can almost tell how wet it will be in the UK from the sea surface temperatures in the preceding 3 months (I say almost as La Nina/El Nino, Humbolts, hurricanes and other weather events can seriously change it in the short term (what is happening at present).

    Think the main thing to remember is that the earth is huge, and the energy from the sun is very big.

    And we worry about a kWh or two or if a meter is measuring to the final Watt :wink:
  7.  
    Posted By: SteamyTea
    Tends to be a more gradual process over several weeks though.
    Not sure where Montreal's rain comes from, ours is from the Gulf of Mexico/Caribbean,


    True, it's a gradual process, but still impressive that so much energy can come together to give a month's rainfall in only 40 minutes! Our rain mainly comes from the Gulf of Mexico too in the summer, though more likely the Pacific in winter (starts with a "Colarado Low" - though if this combines with moisture from the Gulf, we get a "nor'easter" and huge snowfalls.

    Paul in Montreal.
    • CommentAuthorCWatters
    • CommentTimeJun 11th 2012
     
    Posted By: djh I don't see how that has any effect on the ground. The energy released by the rain hitting the ground is its kinetic energy, converted from the gravitational potential energy by falling from a height.


    Thought I'd work some numbers....

    If you had 80mm of water (80kg per square meter) in a cloud at 1000 meters height the PE would be about 784KJ per square meter (80 x 9.8 x 1000 = 784,000)

    The terminal velocity of rain is about 9-10m/s so the KE hitting the ground is only 4kJ per square meter (0.5 x 80 x 10 x 10 = 4000).

    So the vast majority of the PE energy in the rain is lost falling through and heating up the air.

    If the 4KJ released hitting the ground arrives in 40mins the power per square meter is only 1.6 watts per meter.
    • CommentAuthorJoiner
    • CommentTimeJun 12th 2012
     
    :confused:
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