Stories
Slash Boxes
Comments

SoylentNews is people

posted by CoolHand on Tuesday May 28 2019, @07:54PM   Printer-friendly
from the sawing-logs dept.

Most of our building practices aren't especially sustainable. Concrete production is a major source of carbon emissions, and steel production is very resource intensive. Once completed, heating and cooling buildings becomes a major energy sink. There are various ideas on how to handle each of these issues, like variations on concrete's chemical formula or passive cooling schemes.

But now, a large team of US researchers has found a single solution that appears to manage everything using a sustainable material that both reflects sunlight and radiates away excess heat. The miracle material? Wood. Or a form of wood that has been treated to remove one of its two main components.

[...] But rather than simply being structurally useful, the wood has some properties that could make it extremely useful as cladding, covering the exterior of a building. While most of the cellulose fibers are aligned along the grain of the wood, that alignment is very rough—there's plenty of variability in their orientation. That means light that strikes the processed wood will bounce around within a dense mesh of cellulose fibers, scattering widely in the process. The end result is a material that looks remarkably white, in the same way a sugar cube looks white even though each sugar crystal in it is transparent.

As a result, the material is really bad at absorbing sunlight, and thus it doesn't capture the heat in the same way regular wood does.

But it gets better. The sugars in cellulose are effective emitters of infrared radiation, and they do so in two areas of the spectrum where none of our atmospheric gases is able to reabsorb it. The end result is that, if the treated wood absorbs some of the heat of a structure, wood can radiate it away so that it leaves the planet entirely. And the wood is able to do so even while it's being blasted by direct sunlight; the researchers confirmed this by putting a small heater inside a box made of the treated wood and then sticking it in the sunlight in Arizona.


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 2) by Hartree on Tuesday May 28 2019, @08:05PM (4 children)

    by Hartree (195) on Tuesday May 28 2019, @08:05PM (#848647)

    You mean we can solve global warming just by paving the earth with a renewable green material?

    Why we can all just take up carpentry and intensive tree cultivation (like Weyerhauser does) to save the planet and we won't have to send out any more direct mail solicitations for donations to run our 501C3 organizations.

    ...

    Oh. Wait...

    Starting Score:    1  point
    Karma-Bonus Modifier   +1  

    Total Score:   2  
  • (Score: 2) by edIII on Tuesday May 28 2019, @08:30PM (3 children)

    by edIII (791) on Tuesday May 28 2019, @08:30PM (#848657)

    Why land? Earth is 70% water. We could design floating trees of this stuff and put it in Arctic waters. That might draw off enough heat to keep the ice frozen beneath it, and possibly help repair habitats up there. Nothing really stops us from designing floating gardens out in ocean with this stuff.

    If the heat really does leave the Earth, then it may be simply a matter of scaling and timing before we're dumping enough heat to counteract climate change. That's on top of what we could put on land.

    Wonder if this on a large scale could provide power to space? Could small satellites capture that energy and power onboard systems? Would only really be useful at the poles, but having passive power would be neat.

    --
    Technically, lunchtime is at any moment. It's just a wave function.
    • (Score: 0) by Anonymous Coward on Wednesday May 29 2019, @01:20AM

      by Anonymous Coward on Wednesday May 29 2019, @01:20AM (#848731)

      Read the paper (linked from tfa), doesn't work very well with cloud cover. Thus best results in Phoenix.

    • (Score: 1) by khallow on Wednesday May 29 2019, @12:49PM

      by khallow (3766) Subscriber Badge on Wednesday May 29 2019, @12:49PM (#848877) Journal

      We could design floating trees of this stuff and put it in Arctic waters. That might draw off enough heat to keep the ice frozen beneath it, and possibly help repair habitats up there.

      But then you'd increase shipping times from China to Europe by a week or more. My view on the environment pros and cons? Northwest passage > polar bear habitat just on environmental grounds.

    • (Score: 2) by urza9814 on Thursday May 30 2019, @05:49PM

      by urza9814 (3954) on Thursday May 30 2019, @05:49PM (#849364) Journal

      Wonder if this on a large scale could provide power to space? Could small satellites capture that energy and power onboard systems? Would only really be useful at the poles, but having passive power would be neat.

      AIUI, you don't really want to be adding heat to satellites and other spacecraft. They sometimes have problems getting rid of the heat fast enough since there's no air to conduct it away. They try to run low power not just because it's hard to get energy up there, but also because it can be a challenge to get rid of the waste heat it produces. And any heat that gets radiated by this wood is going to be essentially just reflected solar energy so you might as well skip the middle-man and use a solar panel directly.

      Not sure why it would only be useful at the poles either...the special wood is going to be less effective at the poles, since it'll be getting less sunlight and have less heat to radiate away in the first place. And I don't see any reason why a satellite at the poles would be any harder to power than one at the equator -- what might be hard to power is if you want a satellite that just hangs out on the dark side of the planet. Which might be useful for astronomy I guess, but then you probably don't want to be blasting it with a wide beam of reflected heat that might interfere with your readings....

      Not that I'm saying this isn't cool tech...could be great for reducing heating effects of cities, similar to the whole "green roof" ideas that have been going around lately without any of that messy biology stuff. I'd be interested in seeing some kind of comparison between the two actually -- how much energy does this radiate away to space vs how much energy is required to produce it compared to how much energy a typical tree is able to help radiate away by removing greenhouse gasses. Seems like this special wood would require more energy to produce and I'd imagine it probably has a much shorter working lifetime than your average tree, plus the CO2 removed by the tree can keep reducing the energy absorbed by our planet even after the tree is gone, while the wood only works while it's intact and pointing towards the sky. You can't build a skyscraper from living trees and you (probably) can't plant a forest of modified wood, so both will have their niche, but I'd like some actual numbers before we start talking about replacing trees with this stuff. We *could* build a flat, 2D island from this stuff and radiate away some heat, but I'd be kinda shocked if that's better than using the full 3D volume of that ocean for plankton and algae to scrub CO2 instead. Artificial heatsink islands could even have a negative impact by blocking the light from the creatures below.