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Power Technology

An Energy Breakthrough Could Store Solar Power For Decades (bloomberg.com) 92

An anonymous reader quotes a report from Bloomberg: Scientists at Chalmers University of Technology in Gothenburg have figured out how to harness the energy and keep it in reserve so it can be released on demand in the form of heat -- even decades after it was captured. The innovations include an energy-trapping molecule, a storage system that promises to outperform traditional batteries, at least when it comes to heating, and an energy-storing laminate coating that can be applied to windows and textiles. The breakthroughs, from a team led by researcher Kasper Moth-Poulsen, have garnered praise within the scientific community. Now comes the real test: whether Moth-Poulsen can get investors to back his technology and take it to market.

The system starts with a liquid molecule made up of carbon, hydrogen, and nitrogen. When hit by sunlight, the molecule draws in the sun's energy and holds it until a catalyst triggers its release as heat. The researchers spent almost a decade and $2.5 million to create a specialized storage unit, which Moth-Poulsen, a 40-year-old professor in the department of chemistry and chemical engineering, says has the stability to outlast the 5-to 10-year life span of typical lithium-ion batteries on the market today. The most advanced potential commercial use the team developed is a transparent coating that can be applied to home windows, a moving vehicle, or even clothing. The coating collects solar energy and releases heat, reducing electricity required for heating spaces and curbing carbon emissions. Moth-Poulsen is coating an entire building on campus to showcase the technology. The ideal use in the early going, he says, is in relatively small spaces. "This could be heating of electrical vehicles or in houses."
Moth-Poulsen believes there's potential for the system to produce electricity, but his team is focused for now on heating.

"Moth-Poulsen plans to spin off a company that would advance the technology and says he's in talks with venture capital investors," adds Bloomberg. "The storage unit could be commercially available in as little as six years and the coating in three, pending the $5 million of additional funding he estimates will be needed to bring the coating to market."
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An Energy Breakthrough Could Store Solar Power For Decades

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  • Ok, how Many watts of heat can be stored per cubic cm of volume.
    • Re:Energy Density (Score:4, Interesting)

      by KiloByte ( 825081 ) on Tuesday November 05, 2019 @07:14PM (#59385150)

      You probably wanted to ask about joules. The wattage on the other hand is pretty high -- it can release all that heat very rapidly!

      • Re:Energy Density (Score:5, Interesting)

        by sit1963nz ( 934837 ) on Tuesday November 05, 2019 @07:28PM (#59385182)
        Yes,as soon as I hit post I realise my error. However, what is the energy density compared to a lithium cell (which can also release that energy rapidly)
        How many cycles will it last ?
        Can you partially release the energy, or once the catalyst is applied does it trigger a full discharge ?
        What is the method of repeatedly applying the catalyst ?
        What is the cost per joule of energy stored ?
        Do normal airborne contaminants degrade the performance ?
        Toxicity ?

        Lots and lots of questions need to be answered.
        • Re: (Score:3, Informative)

          by Anonymous Coward

          Yes,as soon as I hit post I realise my error. However, what is the energy density compared to a lithium cell (which can also release that energy rapidly)

          lithium-ion is 10 mS/cm at 2.5 volts, their storage is 2.8 mS/cm at 2.3 volt with lithium and 3.2 mS/cm at 2.5 volt for sodiumion.

          How many cycles will it last ?

          It seems to be about the same but they don't have numbers from tests at scale.

          Can you partially release the energy, or once the catalyst is applied does it trigger a full discharge ?

          Yes

          What is the method of repeatedly applying the catalyst ?

          In the lab they mixed the two solutions manually but it will no doubt work the same as current lithium and sodiumion batteries.

          What is the cost per joule of energy stored ?

          As it isn't yet a product manufacturered to scale, and took many attempts, probably stupidly expensive.

          The first lab made lithium ion batteries were around $25,000/kWh from l

          • by rossdee ( 243626 )

            "lithium-ion is 10 mS/cm at 2.5 volts, their storage is 2.8 mS/cm at 2.3 volt with lithium and 3.2 mS/cm at 2.5 volt for sodiumion."

            I presume thats cm^3 for density. but what is S ? Seconds? milliseconds per CC doesn't make sense.

    • Another interesting question is whether the sunlight needs to hit it directly, in which it may be square cm of surface area, which would be much more limiting than cubic cm of volume.

      "Moth-Poulsen is coating an entire building on campus to showcase the technology"

      The showcase application relies on surface area, but the article is thin on details.

      • Yes, he is applying the coating to the outside of the walls so those walls can get sunlight.
        So when this material gets activated on a cold day (on the outside of the walls) how much heat is going to seep into the building vs bugger off into the open air ?

        Improving insulation will be a damned sight more efficient and cost effective.

        This product may have some uses, but warming buildings is NOT going to be one of them.
        • by Hodr ( 219920 )

          Depends on how much storage, and how indirect the light. Could be placed on the inside of glass windows and internal walls that get sunlight during the day, then triggered at night.

          Or, if the storage is really dense, collect in the summer and release in the winter.

          Applications do seem limited though. Car windows might be ideal case.

          • Another interesting question would be... could this "transparent" coating be applied to an existing thermal heating system (e.g. a dark surface area to collect heat and a thermal mass to store it during the day and radiate it at night)? Would the coating provide a net gain of total stored energy, or would the energy stored by the coating reduce the amount of energy going into the existing passive system? I imagine the answer depends on the wavelength(s) of light it gets its energy from.

            Also, the article men

            • Black coatings absorb all wavelengths, hence them being black. Absorption for some materials (carbon nano tubes) is over 99.99%
              So anything in front that absorbs some of that light energy is going to take away energy from what's behind it.
              If it's transparent, it means that it is absorbing a very small fraction of the light because the light has to go through the layer, reflect off what's on the other side, come through the layer again and make it to your eyes.

              This idea is making solar roads look like a w
        • by eth1 ( 94901 )

          So when this material gets activated on a cold day (on the outside of the walls) how much heat is going to seep into the building vs bugger off into the open air ?

          Well, TFA doesn't have any details, but mentions "liquid molecule". The coating might not be of this material itself, but merely a method to expose it to sunlight, after which it can be moved to where heating is actually needed. If that's the case, then it can be transferred inside of the building's insulation before the heat is released. Basically, you'd have a tank of heat in the basement you could use as needed.

          • So, the solution is to have lots and lots of plumbing on the outside of your building. Seems to be extremely impractical and this idea should be in for an ignoble award.
      • I think this is an earlier article on the same group: https://newatlas.com/most-tran... [newatlas.com]
        It's always possible that things have changed dramatically, but the 2017 version looks to have been a liquid pumped through transparent panels, that could capture 1.1% of the sunlight hitting it (up from 0.01% 4 years earlier, so that could have changed quite a bit in the last 2)

      • The article is thin on details because surface area is 2-dimensional.

        Ok, just had to say that...

  • Need a link to the paper, which the Bloomberg story doesn't seem to provide.

    Is this phase-change? Some kind of conformational change? Article is short on details.

    • by EvilSS ( 557649 ) on Tuesday November 05, 2019 @07:23PM (#59385174)
      Here is his bio page. Has all his papers listed. https://www.chalmers.se/en/sta... [chalmers.se]
    • Agreed. Saying a molecule has "carbon, hydrogen, and nitrogen" is like saying a certain mode of transport has 4 wheels. That rules out tractor trailers, bicycles and unicycles. Still a lot of vehicles out there.

      Hopefully the paper(s) has more detail than that.

      We've seen this sort of thing so often: "major breakthrough in solar/battery/energy storage!!1!" that I'll believe the hype when it's on store shelves or in mass use. Not to say the research isn't worth it, just that it tends to get hyped pretty early

    • This paper has the most detail,
      https://research.chalmers.se/p... [chalmers.se]

      The version they are trying to patent has probably not been disclosed, though. His lab is focused on the use of photoswitches for solar thermal storage. It's quite interesting, actually.

    • by PPH ( 736903 )

      Is this phase-change?

      That would be my guess. I have some heating pads full of a gooey liquid. There is a small metal disc 'clicker' inside the plastic pouch. Snap it by squeezing through the pouch and it triggers a phase change which releases heat and changes the liquid to a solid white lump. Throw the pouch into a pan of hot water and the solid melts back to it's gooey state (sorry for the technical terminology) and stays that way.

      I suspect that the clicker creates a local hot spot. Very tiny, but enough to trigger the releas

      • Re: (Score:3, Informative)

        by Maxo-Texas ( 864189 )

        Interesting. Little harder to find than I thought it would be.

        https://aiche.onlinelibrary.wi... [wiley.com]

        "The metallic trigger used in commercial heat packs initiates solidification by releasing minute crystals of solid sodium acetate trihydrate into the subcooled solution. These crystals are harbored in submicron cracks on the disk's surface and are released when the disk is flexed. Using scanning electron microscopy, such seed crystals are observed on the surface of a disk after flexing it. Classic nucleation the

      • by jbengt ( 874751 )
        No, this is not phase change. This is a change from one isomer to a different, metastable isomer.
  • The most advanced potential commercial use the team developed is a transparent coating that can be applied to home windows, a moving vehicle, or even clothing.

    I bet it would be easier to apply if you stopped the vehicle from moving.

    Seriously though:

    The coating collects solar energy and releases heat

    You don't want this on any windows, unless you live somewhere that always requires heating. Normally glass is either coated to reflect solar energy, or it isn't coated so it doesn't reflect it. Coated glass is used in most crappy construction, while uncoated glass is used in passive solar designs where overhangs keep out the sun when you don't want additional heat, and permit it to come through the windows and heat the

    • As you suggest, applying the coating to windows would be a bad idea. The solution is to apply the coating to all the non-window parts of your home.
      • Until you want to. repaint...

        However I am thinking that having this on the outside of walls (so they can get the sunlight) and then releasing that energy (on the outside of the house) during a cold day will be 100% pointless.

        I am tempted to suggest that increasing the insulation in the home may have much better results, cheaper.

        However $5 Million will probably keep his research going until retirement
      • You could combine it with passive solar by coating white interior walls with it, I suppose. That way they'd convert more of the incoming light to heat rather than reflecting it back out of windows. But unless you've got a whole lot of windows, that's probably not going to make a big difference. Still, lots of windows are not uncommon in such designs.

    • Agree that you probably don't want a solar film on your windows if you live in Texas, but if you live in a place like Sweden, where the researchers live, it could be useful. You do need a way to turn it off...it could be as simple as a thin film that you put on your windows when it is cold and remove when it is warm. The desirability of it will depend on how easy it is to apply/remove, cost, and aesthetics.

      There are some details to work out, but it doesn't seem all that crazy to me. Still, their design for

    • by jbengt ( 874751 )

      Normally glass is either coated to reflect solar energy, or it isn't coated so it doesn't reflect it. Coated glass is used in most crappy construction, while uncoated glass is used in passive solar designs where overhangs keep out the sun when you don't want additional heat, and permit it to come through the windows and heat the inside of the room when you do.

      Coating glass is also used to preferentially block infrared and ultraviolet while allowing visible sunlight in. Low emmissivity coatings can help so

  • Totally bogus (Score:5, Interesting)

    by Anonymous Coward on Tuesday November 05, 2019 @07:20PM (#59385162)

    If you read the paper this claim is absolutely bogus and should go with all the other batteries that holds 10x the charge of current batteries or holds the charge for "decades". All just hype.

    These guys post this stuff every year around this time - I'm convinced it's funding related somehow or tied into research grant proposals or some other funding cycle they need to hype things up around.

    Here is LAST years version of this:
    https://www.sciencealert.com/s... [sciencealert.com]

    • Re:Totally bogus (Score:5, Interesting)

      by augustz ( 18082 ) on Tuesday November 05, 2019 @07:23PM (#59385172)

      Here is the 2017 hype one as well.

      https://pvbuzz.com/liquid-stor... [pvbuzz.com]

    • Re: (Score:2, Interesting)

      by sit1963nz ( 934837 )
      Lets see, to get sunlight it needs to be on the outside of walls
      Walls (if people are smart) are insulated
      Releasing all that energy on the OUTSIDE of an insulated wall will do what effectively... heat the building...NO, Dump its heat into the cold air outside...YES

      I have seen perpetual motion machines make more sense than this, and even they are bloody stupid.

      The most important thing to learn from any University is that Genius and Stupidity are NOT mutually exclusive.
    • It's a solar thermal energy storage system. The keyword there is "thermal". It stores heat, not charge. The comparison to Tesla Powerwalls is bogus, but you can blame that on the science writers. The research papers don't make any such claims. Overall, I think the tech is neat. Early stage, but promising.

      • A brick, or parking lot, are also solar thermal energy storage systems. This seems to be in that vein... Any non-100% reflective material will absorb solar heat...
        • Congratulations! You failed to understand the significance of what they are trying to do and why it is not a brick or a parking lot. You could try to educate yourself by reading some of the articles they have published, like this one here [chalmers.se], but please don't let me stop you from trumpeting your ignorance.

        • by AmiMoJo ( 196126 )

          Yes, but it's the ability to do something useful with it that matters.

        • A brick, or parking lot, are also solar thermal energy storage systems. This seems to be in that vein... Any non-100% reflective material will absorb solar heat...

          OK, now this comparison is obtuse. We might as well compare all forms of heat stores to bricks because they store heat. Yeah, that's a TBU (true-but-useless) statement.

          Criticisms of the research should stand on merits, not on trivia snippets and jabs.

      • by tlhIngan ( 30335 )

        It's a solar thermal energy storage system. The keyword there is "thermal". It stores heat, not charge. The comparison to Tesla Powerwalls is bogus, but you can blame that on the science writers. The research papers don't make any such claims. Overall, I think the tech is neat. Early stage, but promising.

        So, like a small scale Heliostat? (The traditional ones are an array of mirrors that concentrate sunlight into a tower which helps a salt molten. From there it's used to heat water to steam and drive a turb

    • This is, after all, a /. article with "could" in the title.

  • by Fly Swatter ( 30498 ) on Tuesday November 05, 2019 @07:28PM (#59385186) Homepage
    Is this like the reaction you get with 2 part epoxy and it gets warm? I don't see where the summary says this is reusable, just that it can store energy for 5-10 years. I will assume it is reusable otherwise it would be a big scam :D

    So you use it on your windows, and when it gets cold inside you just spray the catalyst on the coated windows? No thanks?
    • I don't see where the summary says this is reusable, just that it can store energy for 5-10 years.

      Last year's release from the same group, linked in the described a system that
      - "charges" it by pumping it through a parabolic trough solar collector (one-dimensional focus: Only need to track the sun by season, not time-of-day. Temperature reaches that of process steam).
      - Stores it in a tank (and can be shipped or piped elsewhere for "discharge").
      - "discharges" it by pumping it throu

      • It also answers the energy density: 1 kWhr / 4 kg. Great for a battery, not so great for a fuel.

        That would be in the same ballpark as 18650 Li-ion batteries: the better ones on the market today store about 12 Wh, and weigh about 50 grams. Take 80 of those, and you get the same numbers as above (electro-chemical, that is). But for stationary applications that require heat, size / weight is less important than cost.

        I have no idea what being able to paint things with it is supposed to achieve

        Me neither. This would seem more useful as a kind of solar collector / mass heater / flow battery combo. Take in lots of sun in the summer, chemically 'charge' a storage tank with that, re

        • I really like the idea of being able to energize a liquid with heat and be able to store it without the need for any sort of insulation. In a way, this is what plants do when they synthesize sugar. What would be cool, though, would be to be able to do this en-masse and at will. Imagine a concentrated solar farm not having to deal with, say, the complexities of handling molten salt or worry about losing heat over time.

          Often times it's the idea that sparks technological breakthroughs by giving people a
      • Now that's interesting.

        I designed a thermal accumulator that works, but...it doesn't have great power density. That is: you can switch it on and get what amounts to energy out of nowhere (it's a fancy indirect solar generator), but it won't be a lot of energy. Nothing like you get from a gas turbine.

        Part of this relies on an adiabatic cycle, since I'm effectively playing Maxwell's Demon and exploiting a flaw in one of the engineering limitations of heat pumps: you can't drive a heat pump via a thermal

  • This is like the third amazing battery breakthough in the last 2 weeks alone! I love living in the future. And this one has "garnered praise within the scientific community" so you totally know it is legit! All he needs is $5 million. Lets all take up a collection?

    • Boy when all these AMAZING new battery technologies we've heard about over the past few years come through, we are gonna be Living the Life of Riley for sure! Free power, and lots of it - any time we want it!

    • Totally agree. Investing in new technology development is stupid and a waste of time. Everybody knows that new technology just springs into existence naturally.

      • Totally agree. And every press release needs investment. This guy only needs $5 million to commercialize it. How much are you sending him?

        • It's an article in Bloomberg, written by their science writer staff. Scientists don't write press releases, they write scientific articles that get published in scientific journals. This particular group publishes a lot of them. If they were doing a capital raise, they wouldn't be doing it through Bloomberg, but of course you know that. So what is the objection really? People get excited enough about new science to write it and that's bad? Scientists in early-phase development of a new technology are making

          • Journalists arent merely "writers"

            These scientists went to the press.
            • Many publications have dedicated science writing staff whose job it is to identify and highlight interesting new scientific findings. They will often interview scientists to get quotes, but the scientists did not write the article. Likewise, scientific institutions and journals often have scientific writers whose job is to publicize key findings and circulate it to the main outlets. Again, these tend to have a certain flair intended to attract attention, but they are not written by the scientists.

  • 1 a week, for 20 years.......... nope.

  • by joe_frisch ( 1366229 ) on Tuesday November 05, 2019 @10:08PM (#59385532)

    I think this is it
    https://pubs.rsc.org/en/conten... [rsc.org]

    Looks like solar photons can trigger a chemical change that ends up storing energy with about 50% efficiency - of the input photon energy fig 1. Solar cells typically to better. (note that this 50% applies to photons of exactly the right energy. Photon energy above that is not stored. Photons with lower energy do not generate energy storage).

    The real efficiency seems to be more like 1%, presumably since there are many other absorption mechanisms. So its like a 1% efficient solar cell. they say that the waste energy can be used for water heating, but that is true of normal solar as well - which can have ~20% efficiency to electricity.

    The output of this is thermal not electrical, higher entropy and less useful. (remember an electrically driven heat pump heater can produce more than 1J of heat per input J of energy because it is removing some heat from the environment (for once Carnot is your friend).

    Costs? Saying its inexpensive elements is absurd. Carbon is inexpensive, but diamond is not. Is norbornadiene–quadricyclanesystem, that cheaper per Joule than Lithium batteries? Maybe, but I don't see pricing anywhere. Its a fairly complex organic molecule, so its not clear if it can be manufactured in bulk cheaply.

    At this efficiency though, electric -> hydrogen is still more efficient. (hydrogen isn't great, but a solar -> hydrogen storage -> electricity is still probably >5%. (compared with 1% here).

    Sorry, I just don't see it. Its a very interesting bit of chemistry and it may make sense to fund it based on that, but I just don't see how it can be part of a practical energy system.

    • Agreed that the efficiency isn't very good. I think the benefit is in long term storage. Heat isn't the most useful release mechanism but I can imagine that they could use thermoelectric conversion (Peltier?), with of course even more losses.

      If I were a potential investor (which I am not) they'd need to convince me in what ways this is better than solar + battery storage. If it's about the amount of energy stored, how will it be cheaper than just buying more storage batteries? If it's all about long term

  • Storing energy in window panes... where have I heard s.t. like that:
    https://en.wikipedia.org/wiki/... [wikipedia.org]
    And the original story:
    http://baencd.freedoors.org/Di... [freedoors.org]
    And the sequels (and translations):
    http://www.isfdb.org/cgi-bin/p... [isfdb.org]

    In case the connection is unclear, a reader of Analog later pointed out a dangerous flaw with slow glass: the energy stored would render it explosive.

    • by fintux ( 798480 )

      The explosiveness does not depend directly on the amount of energy, or even energy density. It depends on the maximum rate of energy release. For example, gun powder is not explosive when burnt in an open space, but it is explosive in a closed space (such as ammo). The difference between the two is that in open air, the gun powder burns more slowly.

      Another example is wood, which is generally not considered to be explosive, and lithium ion batteries, which can explode. However, the energy density of wood can

      • You're right, of course. But what would determine the rate of energy release in slow glass? Is it related to tensile strength (which in ordinary glass is quite low, I believe)? Or is it unknowable, because slow glass doesn't exist?

    • Oh, I do remember those stories about "slow glass".. Some of the stories, about glass with images of public crimes delayed for years or of lost family members for which people had to wait to see the images informed my thoughts about public cell phone videos and their common use later.

  • This paper [chalmers.se] by Moth-Poulson describes a compound matching the Bloomberg article - one with only C, O, H atoms. It's an organic molecule with two benzene rings that shifts a bond angle to store solar energy with 1% efficiency. In the paper they're testing it in a solution of toluene. If you're trying to store solar energy in an environmentally friendly way, I'm not sure that benzene compounds dissolved in paint thinner are a good way to go.
    • No way man. I want to sleep next to a window coated with aromatic hydrocarbons with the potential to suddenly release a day's worth of heat if something goes wrong. We live in wildfire country, so I know all my neighbors want that too. /sarc.

  • Take an old mining pit next to a river.
    Cover it in two layers of thick watertight foil.
    Weld them together at the borders.
    Pump water in and out between the foils, and use elevation energy as your storage.
    Hell, you can even have a layer of water and mud above it, to make it invisible and
    even more green.

    Too simple and elegant or too much basic common sense for ya?

    • by fintux ( 798480 )
      This technique is already in use. The problem is that the energy density is not that great. You lift a cubic meter of water 10 meters, and you have reserved less than 0,03 kWh of energy. You cannot heat much with that - a 1 kW heater would run for less than two minutes. That is why the water power plants have usually a big artificial pond above them and a high dam - so that you can store a higher amount of energy. But doing this in a big scale requires big constructions and will bury a big amount of land un
  • A Tree ? (Score:4, Insightful)

    by dbateman ( 150302 ) on Wednesday November 06, 2019 @04:03AM (#59386084)

    Doesn't a tree already do this ? In fact if the tree is fossilised into coal it can store the energy for millions of years and all of this based on the use of the molecule CO2

    D.

  • Silver bullets, silver bullets,
    One and all.
    With all these silver bullets
    Why is there any trouble at all?
  • This work on isomers which store and release heat on demand is awesome. People immediately try to compare it to batteries or fuel as if it's supposed to do their jobs. That's where people start bringing up the energy density.

    This is a non-issue because this heat-storing isomer is so different, and in a remarkably useful way.

    Any time you're changing energy from one form to another, you're dealing with a large loss in efficiency - usually at least 40%. Converting electricity to heat through induction guzzl

  • I can see where this would be a problem. You can't just turn this on and off at will. What if your winter jacket causes you to severely overheat and yet taking it off will put your life in serious danger because of the current weather conditions?

      Thermal runaway and spontaneous combustion of these clothes while stored in a closet also come to mind.

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