
Sponge creates steam using ambient sunlight - jimsojim
http://news.mit.edu/2016/sponge-creates-steam-using-ambient-sunlight-0822
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turtleofdeath
> A solution to this problem came from an unlikely source: Chen’s 16-year-old
> daughter, who at the time was working on a science fair project in which she
> constructed a makeshift greenhouse from simple materials, including bubble
> wrap. “She was able to heat it to 160 degrees Fahrenheit, in winter!” Chen
> says. “It was very effective.”

Love it when discoveries are made by accident.

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zellyn
That doesn't sound like an accident: it sounds like she considered the
problem, and thought of a solution, on purpose.

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semi-extrinsic
I hate to be the negative guy, but isn't this the obvious, standard, well
known way of building a greenhouse? You want to prevent hot air from escaping,
you put up something that contains the air. An actual greenhouse doesn't
really rely on "the greenhouse effect" of allowing visual light to pass but
being opaque to infrared. It's all about preventing hot air from rising. This
can be easily seen in polyethylene windowed greenhouses, which get just as hot
as glass greenhouses, even though polyethylene is just as transparent to IR as
to visible light.

That part of the piece seemed like something the MIT press office coaxed out
of them to get a human interest angle TBH.

Really, most of their improvement over the 2014 version seems to come from the
spectrally-selective absorber coating, which is a lot more expensive than
bubble wrap. So they say this solution might be ~10x cheaper than existing
solar destilling plants, but they also say it will need replacement ~10x as
often. So depending on exactly how the numbers work out, this might mean
slightly cheaper, more labor-intensive desalinisation plants, but we're not
covering any deserts just yet.

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SiVal
_The sponge also converted 20 percent of the incoming sunlight to steam. ...
The researchers’ current design builds on a solar-absorbing structure they
developed in 2014 ... that was able to boil water to 100 C and convert 85
percent of the incoming sunlight to steam._

Even if they're a little confused about turning energy into matter, it does
make me wonder if it's possible to manufacture something cheap, flexible, and
durable enough that you could carry a "solar still" blanket for survival
purposes. Just unroll it over some moist sand or vegetation, and it would
distill and collect water that you could then drink out of a little tube.

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AceJohnny2
> _It seems MIT buried the lead. They 've found a way to convert sunlight to
> steam. Should come in very handy in space._

Space has the opposite problem: Remember that vacuum is a perfect insulator.
The problem is usually about being able to dump excess heat.

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wahern
Radiative cooling. Vacuum flasks wouldn't work nearly as well as they do if
the internal walls weren't reflective.

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option_greek
Can covering coastal waters with these sheets create artificial/on-demand
clouds ? That would be awesome for drought prone areas!

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tomahunt
The paper is available on researchgate:
[https://www.researchgate.net/profile/Hadi_Ghasemi10/publicat...](https://www.researchgate.net/profile/Hadi_Ghasemi10/publication/264091569_Solar_steam_generation_by_heat_localization/links/53e0e5240cf24f90ff60c047.pdf)

Original link: www.nature.com/articles/ncomms5449

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smpetrey
So, what will this breakthrough mean for desalination efforts?

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jrapdx3
I assume the idea would be to condense the steam as distilled water, and feed
the brine back into the brackish water source. Probably the engineering
challenges would be getting the salt water into the evaporator, collecting and
condensing the vapor, and removing the "used" brine from the evaporator, and
making these components operate continuously.

From the article it sounded like this was an idea that was being considered.

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stcredzero
_the researchers found the structure heated water to its boiling temperature
of 100 degrees Celsius, even on relatively cool, overcast days._

It's not surprising that one could get such a result from solar thermal. Heat
pipe based solar collectors have been doing this in cloudy English environs
for many years. The really impressive part of this solution is its potential
extremely low cost.

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dharma1
any instructions how to replicate?

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apple314159
This really is vapor ware!

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Taek
Please make sure all comments contribute to the article.

Humor is okay, but should at most be supplementing a more thoughtful comment,
and not be the primary contribution of a comment.

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andrewrice
Is that in the guidelines?

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kbenson
That's sort of an informal rule-of-thumb a lot follow. Amusingly, the
guidelines do specifically say "Please don't submit comments complaining that
a submission is inappropriate for the site."

Really, the simplest thing to do is make sure you contribute to discussion in
some small way, and then put a rider on for the less contributive aspects you
want to voice. That's what the above is really espousing, and while it's not a
rule, it does seem to make the discussion flow smoother (and prevents people
from jumping in about how you aren't contributing...)

