6 ms·

Energy Breakthrough could Store Solar Power for Decades

113 points by sdan 7y ago

neonate 7y ago
http://archive.is/Ayuyv http://archive.is/Ayuyv
jjtheblunt 7y ago
Titles with "could" seem strongly correlated with clickbait.
- sneilan1 7y ago
  Sociologists discover titles with “could” could be correlated with clickbait. FTFY :-)
nmeofthestate 7y ago
As soon as I read that eco-something could be used to "coat windows, or even clothing", I just assume it's bollocks.
- jackhack 7y ago
  nothing like having a molecular coating on one's clothing storing large amounts of energy, and releasing it as heat. What could go wrong? However, this type of storage might have promise as a power source for an external combustion engine like the Sterling? https://en.wikipedia.org/wiki/External_combustion_engine https://en.wikipedia.org/wiki/External_combustion_engine
iamaelephant 7y ago
Bloomberg. Proceed with extreme caution.
pjc50 7y ago
Real paper, I think (from the linked principal researcher): https://research.chalmers.se/publication/511209/file/511209_Fulltext.pdf https://research.chalmers.se/publication/511209/file/511209_... The claims are reduced somewhat: > The system features several attractive properties, such as a long energy storage half-life (40 h) at room temperature, > Concerning the energy storage efficiency, 0.88% of the solar energy could theoretically be stored in a neat sample (S5, ESI†). The highest efficiency that can be expected for a 5104M solution is 0.02%, and for a 2104M solution is 0.01% > However, the reaction rate was still too low to be used for macroscopic heat release purposes This isn't a commercialisable solution. What this is, is fundamental research. Which often looks completely terrible because it's a first attempt at something. Once the relevant quantum effects are more understood, better candidate chemicals can be developed.
- jkepler 7y ago
  Thanks for finding the real paper. Much more useful than Bloomberg's paywall.
- layoutIfNeeded 7y ago
  > What this is, is fundamental research. Which often looks completely terrible because it's a first attempt at something. In the case of energy storage it’s more common to see research that looks promising in the journals but never materializes at scale.
- gene-h 7y ago
  So this work seems to be about demonstrating the engineering aspects of molecular solar thermal energy storage. They put all this work into describing the microfluidic chip they use, pumps, and other details. They also use an azobenzene derivative for energy storage, which was probably chosen because the synthesis of it was trivial(2 steps) meaning it was easy for them to make enough for the test set up. Azobenzene has been considered for solar thermal energy storage since about 1976, and I suspect even earlier[0]. But there are better molecules out there. In this paper here[1] the same authors develop a molecule based around norbornadiene that has an estimated energy storage efficiency of 3.8%, an energy density of 0.48 MJ/kg, and a half life of 10 months. They even have a molecule with a half life of 18 years in one of their tables. So this publication is probably more in line with the storing solar power for decades from the headline. [0]https://www.sciencedirect.com/science/article/abs/pii/0038092X83901561 https://www.sciencedirect.com/science/article/abs/pii/003809... [1]https://research.chalmers.se/publication/510123/file/510123_Fulltext.pdf https://research.chalmers.se/publication/510123/file/510123_...
- jimrandomh 7y ago
  Paper: "a long energy storage half-life (40 h) at room temperature" Headline: "Energy Breakthrough could Store Solar Power for Decades" This is too egregious a misrepresentation by Bloomberg to let slide. Flagged, and I encourage others to do the same.
  - xster 7y ago
gene-h 7y ago
Disappointingly this article doesn't provide a link to the research. I think this paper might be it[0], but I am not sure. So in the paper they develop a material that has an estimated storage efficiency of 3.8%(this might be solar conversion efficiency) and energy density of 0.48 MJ/kg. This material is what's called a photochromic meaning it changes color when exposed to sunlight. This is just like those glasses which darken when you go outside. Well it turns out that many photochromic molecules accomplish this by changing or reconfiguring their molecular structure, with azobenzene being the classic example of this[1]. Now as you may know color changing glasses eventually change back to their original color, this is because the color changed state is at a little bit higher energy than the clear state. There might be a bit of a hill it has to overcome before it can go all the way downhill to the lower energy state, but eventually random thermal motion will push it over. So because the color changed state is at higher energy it can release energy as it falls down. So the interesting thing they show here is that their molecule has a half life or rate at which it converts back to its original form of 10 months, which is a pretty long time. The energy density is also pretty good too, 0.48 MJ/kg is about the energy density of alkaline batteries. And while 3.8% energy conversion efficiency seems pretty bad it's pretty good for photochromic materials of which efficiencies less than 1% are typical. Of course they want to put this in windows and since you can't make the whole window out of this material the energy density of the material+window plastic ends up being ~2.7-3.8 kJ/kg. Of course there's another problem here too. The material they develop is yellow in its uncharged state only converting to clear when exposed to sufficient sunlight, which may not be very attractive to consumers. [0]https://research.chalmers.se/publication/510123/file/510123_Fulltext.pdf https://research.chalmers.se/publication/510123/file/510123_... [1]https://en.wikipedia.org/wiki/Azobenzene https://en.wikipedia.org/wiki/Azobenzene [2]https://en.wikipedia.org/wiki/Energy_density https://en.wikipedia.org/wiki/Energy_density
- DoctorOetker 7y ago
  table 1 of the paper you reference [0], also lists "N5d" with a half-life of 18 years I am confused with the different efficiency metrics, one kind of metric hovers around the single digit percentages, but Table 1 lists Φ/photo conversion [%] between 46% and 77% ... This is substance 2l in the referenced paper at https://doi.org/10.1002/chem.201802932 https://doi.org/10.1002/chem.201802932
daddylonglegs 7y ago
I think the domestic applications are partly covered by phase change materials: waxes selected for a melting point at the desired temperature. So, for example, you can embed a 23C phase change material in the plaster of a room - giving the room a high apparent thermal mass at the temperature you want it to stay at. A phase change material formulated to melt at 60C can make a hot water tank much "bigger" for coupling with a solar thermal system. These days houses can and should be built with enough insulation that they need very little heating (in most climes). On the other hand there probably are valuable industrial applications for this sort of material, particularly now that we really want high efficiency. There might even be uses in neighbourhood or utility scale power project.
lr 7y ago
Articles like this remind me of this house, which was built in Iowa City, IA by a Physics professor (he was my professor for several classes). At the time this house was being built, ISU had an "active solar" research facility, i.e., using all kinds of mechanical means to turn solar energy into heat for homes. Once this house was built, ISU shut down the "active solar" research because, as this house showed, passive solar was just so, so much cheaper and efficient: https://lhodges.public.iastate.edu/house.htm https://lhodges.public.iastate.edu/house.htm
- frankus 7y ago
  That equation is definitely changing with modern PV prices and heat pumps: https://www.greenbuildingadvisor.com/article/solar-thermal-is-really-really-dead https://www.greenbuildingadvisor.com/article/solar-thermal-i...
  - jonstewart 7y ago
    Yes. Successful passive solar homes typically aren't all that passive, as they often need fans to transfer heat between the solar space and the storage medium (e.g., Hodges's house had pipes in the cement floor with fans; it was also common in other passive solar houses to have a massive rock bed beneath the foundation with air ducted through it). The traditional passive solar house where a mass floor is heated really only works in climates where it's sunny on a regular basis in winter (basically, the Plains, Rockies, and Southwest). If it can get cloudy, the house will need far more thermal storage and a means of heat transfer and control. The capital cost of the storage and system is considerable, and then operation requires maintenance. Also, the glazing typically needs to be covered overnight to keep from radiating all the heat out. It's not very passive. (I own a so-called passive solar home which is woefully lacking in storage; on a sunny day it'll heat up to 78F inside, but it will lose all the heat out the windows overnight). Contrast with the one-two punch that is heat pumps and solar panels, each benefiting from mass manufacturing economies of scale. The heat pump can pull in 3KW of heat for every 1KW of electricity applied, and the solar panel can provide the electricity. The total cost is probably less than $20K, works just about anywhere, and provides air conditioning in the summer.
gwbas1c 7y ago
> A big unknown is whether the system can produce electricity. So what! In the winter, demand for energy goes up for heating. With current solar technology, it's impossible for someone to stockpile energy from rooftop solar for winter heating. (Net metering is a numbers game.) If this works, and I could somehow put panels on my roof or exterior walls that allow me to stockpile energy throughout the year to use for winter heating, it would be "the solution" for me. Edit: I should add, anyone who sells a "magic thing" that charges up throughout the year, and then provides free heat through the winter, will be extremely rich.
tempguy9999 7y ago
Could any physicist speculate on the viability of using the Wigner energy for energy storage. Questions are, energy density, ease of 'injecting' the energy, how controlled can the release be, anything else.
dredmorbius 7y ago
Oddly enough, there's a chemical with proved hundred-million-year-plus storage capability for solar power, of the general form CnH2n+2: https://en.wikipedia.org/wiki/Hydrocarbon https://en.wikipedia.org/wiki/Hydrocarbon Though in recent decades sourced from naturally-occurring reserves, a practice which raises both suffiency and unintended consequence concerns, these are also produced within the biosphere (though at levels insufficient to present or projected future levels of human consumption), and may be synthesized by artificial means from surplus electricity generation, or possibly, other forms of energy. https://en.wikipedia.org/wiki/Synthetic_fuel https://en.wikipedia.org/wiki/Synthetic_fuel
- marcosdumay 7y ago
  Those require a large deal of work to be reformed into an usable form after storage. Even an year is enough to damage them to the point that they are unfit for many mainstream applications.
  - dredmorbius 7y ago
    If directly synthesized in to desired forms, absent an antifungicidal treatment, storage for months to decades is well within reason. Particularly for direct thermal use. The problem with the really old stuff is that the synthesis process was a bit slipshod and the Designer(s) failed to anticipate the strict quality controls required of present consumers.

113 points by sdan 7y ago

neonate 7y ago

http://archive.is/Ayuyv http://archive.is/Ayuyv

jjtheblunt 7y ago

Titles with "could" seem strongly correlated with clickbait.

sneilan1 7y ago
Sociologists discover titles with “could” could be correlated with clickbait. FTFY :-)

nmeofthestate 7y ago

As soon as I read that eco-something could be used to "coat windows, or even clothing", I just assume it's bollocks.

jackhack 7y ago
nothing like having a molecular coating on one's clothing storing large amounts of energy, and releasing it as heat. What could go wrong? However, this type of storage might have promise as a power source for an external combustion engine like the Sterling? https://en.wikipedia.org/wiki/External_combustion_engine https://en.wikipedia.org/wiki/External_combustion_engine

iamaelephant 7y ago

Bloomberg. Proceed with extreme caution.

pjc50 7y ago

Real paper, I think (from the linked principal researcher): https://research.chalmers.se/publication/511209/file/511209_Fulltext.pdf https://research.chalmers.se/publication/511209/file/511209_... The claims are reduced somewhat: > The system features several attractive properties, such as a long energy storage half-life (40 h) at room temperature, > Concerning the energy storage efficiency, 0.88% of the solar energy could theoretically be stored in a neat sample (S5, ESI†). The highest efficiency that can be expected for a 5104M solution is 0.02%, and for a 2104M solution is 0.01% > However, the reaction rate was still too low to be used for macroscopic heat release purposes This isn't a commercialisable solution. What this is, is fundamental research. Which often looks completely terrible because it's a first attempt at something. Once the relevant quantum effects are more understood, better candidate chemicals can be developed.

jkepler 7y ago
Thanks for finding the real paper. Much more useful than Bloomberg's paywall.
layoutIfNeeded 7y ago
> What this is, is fundamental research. Which often looks completely terrible because it's a first attempt at something. In the case of energy storage it’s more common to see research that looks promising in the journals but never materializes at scale.
gene-h 7y ago
So this work seems to be about demonstrating the engineering aspects of molecular solar thermal energy storage. They put all this work into describing the microfluidic chip they use, pumps, and other details. They also use an azobenzene derivative for energy storage, which was probably chosen because the synthesis of it was trivial(2 steps) meaning it was easy for them to make enough for the test set up. Azobenzene has been considered for solar thermal energy storage since about 1976, and I suspect even earlier[0]. But there are better molecules out there. In this paper here[1] the same authors develop a molecule based around norbornadiene that has an estimated energy storage efficiency of 3.8%, an energy density of 0.48 MJ/kg, and a half life of 10 months. They even have a molecule with a half life of 18 years in one of their tables. So this publication is probably more in line with the storing solar power for decades from the headline. [0]https://www.sciencedirect.com/science/article/abs/pii/0038092X83901561 https://www.sciencedirect.com/science/article/abs/pii/003809... [1]https://research.chalmers.se/publication/510123/file/510123_Fulltext.pdf https://research.chalmers.se/publication/510123/file/510123_...
jimrandomh 7y ago
Paper: "a long energy storage half-life (40 h) at room temperature" Headline: "Energy Breakthrough could Store Solar Power for Decades" This is too egregious a misrepresentation by Bloomberg to let slide. Flagged, and I encourage others to do the same.
- xster 7y ago

gene-h 7y ago

Disappointingly this article doesn't provide a link to the research. I think this paper might be it[0], but I am not sure. So in the paper they develop a material that has an estimated storage efficiency of 3.8%(this might be solar conversion efficiency) and energy density of 0.48 MJ/kg. This material is what's called a photochromic meaning it changes color when exposed to sunlight. This is just like those glasses which darken when you go outside. Well it turns out that many photochromic molecules accomplish this by changing or reconfiguring their molecular structure, with azobenzene being the classic example of this[1]. Now as you may know color changing glasses eventually change back to their original color, this is because the color changed state is at a little bit higher energy than the clear state. There might be a bit of a hill it has to overcome before it can go all the way downhill to the lower energy state, but eventually random thermal motion will push it over. So because the color changed state is at higher energy it can release energy as it falls down. So the interesting thing they show here is that their molecule has a half life or rate at which it converts back to its original form of 10 months, which is a pretty long time. The energy density is also pretty good too, 0.48 MJ/kg is about the energy density of alkaline batteries. And while 3.8% energy conversion efficiency seems pretty bad it's pretty good for photochromic materials of which efficiencies less than 1% are typical. Of course they want to put this in windows and since you can't make the whole window out of this material the energy density of the material+window plastic ends up being ~2.7-3.8 kJ/kg. Of course there's another problem here too. The material they develop is yellow in its uncharged state only converting to clear when exposed to sufficient sunlight, which may not be very attractive to consumers. [0]https://research.chalmers.se/publication/510123/file/510123_Fulltext.pdf https://research.chalmers.se/publication/510123/file/510123_... [1]https://en.wikipedia.org/wiki/Azobenzene https://en.wikipedia.org/wiki/Azobenzene [2]https://en.wikipedia.org/wiki/Energy_density https://en.wikipedia.org/wiki/Energy_density

DoctorOetker 7y ago
table 1 of the paper you reference [0], also lists "N5d" with a half-life of 18 years I am confused with the different efficiency metrics, one kind of metric hovers around the single digit percentages, but Table 1 lists Φ/photo conversion [%] between 46% and 77% ... This is substance 2l in the referenced paper at https://doi.org/10.1002/chem.201802932 https://doi.org/10.1002/chem.201802932

daddylonglegs 7y ago

I think the domestic applications are partly covered by phase change materials: waxes selected for a melting point at the desired temperature. So, for example, you can embed a 23C phase change material in the plaster of a room - giving the room a high apparent thermal mass at the temperature you want it to stay at. A phase change material formulated to melt at 60C can make a hot water tank much "bigger" for coupling with a solar thermal system. These days houses can and should be built with enough insulation that they need very little heating (in most climes). On the other hand there probably are valuable industrial applications for this sort of material, particularly now that we really want high efficiency. There might even be uses in neighbourhood or utility scale power project.

lr 7y ago

Articles like this remind me of this house, which was built in Iowa City, IA by a Physics professor (he was my professor for several classes). At the time this house was being built, ISU had an "active solar" research facility, i.e., using all kinds of mechanical means to turn solar energy into heat for homes. Once this house was built, ISU shut down the "active solar" research because, as this house showed, passive solar was just so, so much cheaper and efficient: https://lhodges.public.iastate.edu/house.htm https://lhodges.public.iastate.edu/house.htm

frankus 7y ago
That equation is definitely changing with modern PV prices and heat pumps: https://www.greenbuildingadvisor.com/article/solar-thermal-is-really-really-dead https://www.greenbuildingadvisor.com/article/solar-thermal-i...
- jonstewart 7y ago
  Yes. Successful passive solar homes typically aren't all that passive, as they often need fans to transfer heat between the solar space and the storage medium (e.g., Hodges's house had pipes in the cement floor with fans; it was also common in other passive solar houses to have a massive rock bed beneath the foundation with air ducted through it). The traditional passive solar house where a mass floor is heated really only works in climates where it's sunny on a regular basis in winter (basically, the Plains, Rockies, and Southwest). If it can get cloudy, the house will need far more thermal storage and a means of heat transfer and control. The capital cost of the storage and system is considerable, and then operation requires maintenance. Also, the glazing typically needs to be covered overnight to keep from radiating all the heat out. It's not very passive. (I own a so-called passive solar home which is woefully lacking in storage; on a sunny day it'll heat up to 78F inside, but it will lose all the heat out the windows overnight). Contrast with the one-two punch that is heat pumps and solar panels, each benefiting from mass manufacturing economies of scale. The heat pump can pull in 3KW of heat for every 1KW of electricity applied, and the solar panel can provide the electricity. The total cost is probably less than $20K, works just about anywhere, and provides air conditioning in the summer.

gwbas1c 7y ago

> A big unknown is whether the system can produce electricity. So what! In the winter, demand for energy goes up for heating. With current solar technology, it's impossible for someone to stockpile energy from rooftop solar for winter heating. (Net metering is a numbers game.) If this works, and I could somehow put panels on my roof or exterior walls that allow me to stockpile energy throughout the year to use for winter heating, it would be "the solution" for me. Edit: I should add, anyone who sells a "magic thing" that charges up throughout the year, and then provides free heat through the winter, will be extremely rich.

tempguy9999 7y ago

Could any physicist speculate on the viability of using the Wigner energy for energy storage. Questions are, energy density, ease of 'injecting' the energy, how controlled can the release be, anything else.

dredmorbius 7y ago

Oddly enough, there's a chemical with proved hundred-million-year-plus storage capability for solar power, of the general form CnH2n+2: https://en.wikipedia.org/wiki/Hydrocarbon https://en.wikipedia.org/wiki/Hydrocarbon Though in recent decades sourced from naturally-occurring reserves, a practice which raises both suffiency and unintended consequence concerns, these are also produced within the biosphere (though at levels insufficient to present or projected future levels of human consumption), and may be synthesized by artificial means from surplus electricity generation, or possibly, other forms of energy. https://en.wikipedia.org/wiki/Synthetic_fuel https://en.wikipedia.org/wiki/Synthetic_fuel

marcosdumay 7y ago
Those require a large deal of work to be reformed into an usable form after storage. Even an year is enough to damage them to the point that they are unfit for many mainstream applications.
- dredmorbius 7y ago
  If directly synthesized in to desired forms, absent an antifungicidal treatment, storage for months to decades is well within reason. Particularly for direct thermal use. The problem with the really old stuff is that the synthesis process was a bit slipshod and the Designer(s) failed to anticipate the strict quality controls required of present consumers.