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Mechanical power generation using Earth's ambient radiation

science.org

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Re: Mechanical power generation using Earth's ambient radiation

#51

Post by marcosdumay »

kragen wrote: post #40
jcims wrote: post #14

DIY radiative cooling paint from YouTuber NightHawkInLight - https://www.youtube.com/watch?v=N3bJnKmeNJY&list=PL1a2HkcVbm... It has pretty impressive performance. Tech Ingredients did one or two vids as well - https://www.youtube.com/watch?v=dNs_kNilSjk Was thinking of whipping up a batch for my rv.

IIRC, the papers they're working from mention that lime works very nearly as well as the baryta they're using. Guess what people have been painting their houses white with for several thousand years?

Not with the optimal mixture for maximum-packing of limestone nanospheres.

That effect is almost not perceptible in normal milled limestone.

Re: Mechanical power generation using Earth's ambient radiation

#52

Post by throwaway34564 »

Slightly off-topic - I was momentarily excited this was a replication of https://journals.aps.org/prapplied/abstract/10.1103/PhysRevA... (Electric Power Generation from Earth’s Rotation through its Own Magnetic Field)

I've been stalking the citations for this paper for a while now. Surely people would be scrambling to replicate these results. It could truly be transformative for the world if it works and is scale-able.

The science looks good to me

Re: Mechanical power generation using Earth's ambient radiation

#53

Post by cameldrv »

viraj_shah wrote: post #34
cameldrv wrote: post #29

Not an engine, but some friends of mine got a mylar sheet that's black on one side and reflective on the other. We tried it out in the desert tied onto trees/vehicles. You put the shiny side down, so the hot IR radiation of the earth is reflected away, and the black side sees the extremely cold (in IR) desert sky. If you put a little hole in the middle and put a bucket under it, you get a fair bit of water, because t…

Fascinating 20 degrees C is huge. What's a fair bit of water? At what time of day and how long did you collect water?

I didn't do the measurment and it's been a while so it's possible I misremembered the temperature delta, or maybe it was degrees F. It was about a 2-3 square meter sheet and it made about a liter of water overnight.

Re: Mechanical power generation using Earth's ambient radiation

#54

Post by IAmBroom »

andbberger wrote: post #26
nine_k wrote: post #24

Earlier quoted context omitted.

This can't be correct. 10,000 TWh/y = 1e+7 GWh/y, divide it by 365.25 days/y to produce daily output of 27,379 GWh/day, then by 24 h/day to get pure power of 1,141 GW. It's still more than a terawatt, three orders of magnitude larger than the largest nuclear reactors.

oops. yes. still not that much though. i mean it's a lot but it's "one more large industrialized country" a lot not "kardashev 2" a lot

Those goalposts of yours are on a FTL ship...

Re: Mechanical power generation using Earth's ambient radiation

#55

Post by burnt-resistor »

Davis is so frickin windy, wind power would be my first choice.

Secondarily, using a deep ground source heat pump to power a Stirling cycle engine would probably be much more powerful than harvesting a few mW from ambient temperature gradient between surface and air.

That's my 2 centidollars.

Re: Mechanical power generation using Earth's ambient radiation

#56

Post by IAmBroom »

aetherspawn wrote: post #4
AnimalMuppet wrote: post #3

400 milliwatts per square meter? That's interesting that they can do it at all, but that level is completely impractical for real use.

> the generation of >400 milliwatts per square meter of mechanical power with a potential for >6 watts per square meter. Keep in mind the power is fully mechanical so no electricity or control circuit is required. And based on the simplicity it seems like a good candidate to power something that you need to last 100 years with no maintenance for example.

No moving parts in open water last without maintenance. Life, uh, finds a way.

Re: Mechanical power generation using Earth's ambient radiation

#57

Post by burnt-resistor »

cameldrv wrote: post #29

Not an engine, but some friends of mine got a mylar sheet that's black on one side and reflective on the other. We tried it out in the desert tied onto trees/vehicles. You put the shiny side down, so the hot IR radiation of the earth is reflected away, and the black side sees the extremely cold (in IR) desert sky. If you put a little hole in the middle and put a bucket under it, you get a fair bit of water, because t…

Neat. Reminds me that Applied Science made an acoustic radiometer video recently. https://youtu.be/lAeJvZfVLbE

Re: Mechanical power generation using Earth's ambient radiation

#58

Post by burnt-resistor »

Animats wrote: post #30

> 400 milliwatts per square meter About two orders of magnitude weaker than solar panels, even over 24 hours. E = (T2-T1) / T2

RF energy harvesting in urban areas results in about 0.5-5 mW/m^2. I would guess it would be about 1-2 orders of magnitude less in rural areas.

This is like shaving nickels to make money.

Certainly, there are better energy sources like the fusion reactor in the sky and building a fusion reactor (that's perpetually 30 years away).

TIL: Active nuclear reactors of all types around the world are mappable using antineutrino detectors. It would probably also expose the location of every stationary nuclear-powered ship and submarine too.

Re: Mechanical power generation using Earth's ambient radiation

#60

Post by [deleted] »

wombatpm wrote: post #33
cameldrv wrote: post #29

Not an engine, but some friends of mine got a mylar sheet that's black on one side and reflective on the other. We tried it out in the desert tied onto trees/vehicles. You put the shiny side down, so the hot IR radiation of the earth is reflected away, and the black side sees the extremely cold (in IR) desert sky. If you put a little hole in the middle and put a bucket under it, you get a fair bit of water, because t…

Now you just need a couple of droids and you could go into the moisture farming business

[deleted]
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