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Power Science Technology

Graphene Solar Thermal Film Could Be a New Way To Harvest Renewable Energy (ieee.org) 23

An anonymous reader quotes a report from IEEE Spectrum: Researchers at the Center for Translational Atomaterials (CTAM) at Swinburne University of Technology in Melbourne, Australia, have developed a new graphene-based film that can absorb sunlight with an efficiency of over 90 percent, while simultaneously eliminating most IR thermal emission loss -- the first time such a feat has been reported. The result is an efficient solar heating metamaterial that can heat up rapidly to 83 degrees C (181 degrees F) in an open environment with minimal heat loss. Proposed applications for the film include thermal energy harvesting and storage, thermoelectricity generation, and seawater desalination.

The 3D structured graphene metamaterial (SGM) is composed of a 30-nanometer-thick film of alternating graphene and dielectric layers deposited on a trench-like nanostructure that does double duty as a copper substrate to enhance absorption. More importantly, the substrate is patterned in a matrix arrangement to enable flexible tunability of wavelength-selective absorption. The graphene film is designed to absorb light between 0.28- to 2.5-micrometer wavelengths. And the copper substrate is structured so that it can act as a selective bandpass filter that suppresses the normal emission of internally generated blackbody energy. This retained heat then serves to further raise the metamaterial's temperature. Hence, the SGM can rapidly heat up to 83 degrees C. Should a different temperature be required for a particular application, a new trench nanostructure can be fabricated and tuned to match that specific blackbody wavelength.
"The new material also uses less graphene by significantly reducing the film thickness to one third, and its thinness aids in transferring the absorbed heat more efficiently to other media such as water," the report adds. "Additionally, the film is hydrophobic, which fosters self-cleaning, while the graphene layer effectively protects the copper layer from corrosion, helping to extend the metamaterial's lifetime."

The research is published in the journal Nature Communications.
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Graphene Solar Thermal Film Could Be a New Way To Harvest Renewable Energy

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  • It's not just for breakfast anymore.

    • Found this recipe for solor cells on Youtube but I haven't tried it myself yet.
      They said it was highly experimental and nobody should try to repeat it before they perfected the necessary steps.
      So I strongly suggest nobody else tries it and leave it to the youtube professionals.

      1. Take a sheet of plastic wrap
      2. Take a bite of your favorite cereal
      3. Chew at least 50 times
      4. spit it out on the plastic sheet
      5. carefully spread it out in an even layer
      6. bake it at least 3 hours in your oven
      Now look at all the bl

  • by DavenH ( 1065780 ) on Wednesday March 25, 2020 @08:02PM (#59872142)
    Hardly a better duo than these two words in Slashdot headlines.
    • The summary's trying very hard to go for bingo too... on top of "graphene".

      "matrix", "nanostruture", "metamaterial", "flexible tunability", "self-cleaning", even "3D"

      I think I need a shower now, just for typing all those.

  • by thesjaakspoiler ( 4782965 ) on Wednesday March 25, 2020 @09:37PM (#59872324)

    ...... ow ...... still waiting for my thin film solar cells to roll out of the factory.
    Pre-ordered them about 20 years ago or so.

  • Instead of just using a looooong black hose?

    • by hey! ( 33014 )

      After the Energy Crisis in the 1970s, some people installed solar hot water systems on their roof. There's even a few You wouldn't do that today, but back then photovoltaics were less efficient and more expensive than they are today.

      Efficiency is not as economically critical for renewable energy than it is for fossil fuels, but it may matter when choosing a technology for an application. If you could build a heat-generating *system* that was as a whole system more efficient than photovolatics and electric

      • I can assure you that we are still doing the same as of today in Greece and as far as I know in Israel, Cyprus, Turkey and many many more other countries that have lot's of sun. The reason? Many! 1. All day (almost all year round) instant hot water without having to use any other water warming system that has higher possibility of failure 2. Environmental friendly 3. payback in around 15 years. Yeah I know it's slow but you have other benefits as well mentioned above
  • Something they didn't say that I'm sure the inventors calculated: How long would it take to heat a cube of water in a box of this stuff, assuming typical sunlight? Or how about make a pizza box out of thin metal and this film, then see how fast it can reheat a cold slice? Or would the "blackest substance" (link [mit.edu], link [fastcompany.com]) recently discovered do a better job?
  • Between Trump and COVID-19 it feels like an eternity since Graphene has been in the headlines. Maybe the world is returning to some kind of normality. I suspect a cold fusion article to pop up next week.

  • And of course, commercial availability is 5-7 years away...

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