

Japanese plan to solve world’s energy problems: Turn moon into a solar panel - WestCoastJustin
http://news.nationalpost.com/2013/11/29/japans-crack-plan-to-solve-the-worlds-energy-problems-turn-the-moon-into-a-giant-solar-panel/

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deeths
Even if this was feasible, atmospheric heating from the microwaves interacting
with the atmosphere (as well as water vapor and particles in it) would be a
real problem. This would be equivalent to the Sun heating the earth+atmosphere
on the order of a few percent more than it already does (see below).

This seems like a pretty intractable problem with these sorts of plans to beam
energy to earth.

\--- showing my work...

Microwaves attenuate in the atmosphere at about 15 dB/km or 3%/km (see
[http://dspace.mit.edu/bitstream/handle/1721.1/4963/RLE-
TR-08...](http://dspace.mit.edu/bitstream/handle/1721.1/4963/RLE-
TR-087-14236979.pdf)). If the signal is losing power, its going somewhere:
notably as energy (some converted to heat) into the atmosphere.

If you're sending 13 PetaWatts (as indicated in the original link) through 10+
km of atmosphere, that's 3.400 PetaWatts, or 26% of the power, "lost" on the
way to earth. All the power that's "lost" is being absorbed by the atmosphere
and contributing to atmospheric heating.

The earth gets 174 Petawatts of incoming radiation from the Sun
([http://en.wikipedia.org/wiki/Solar_energy](http://en.wikipedia.org/wiki/Solar_energy)),
but 30% of that actually gets reflected back, so the Sun heats with 122 PW of
incoming solar radiation and this plan would add 3.4 PW, 3% more.

Note that I didn't take into account the thinning of the atmosphere or the
fact that not all the energy goes into heat (some of it could be absorbed in
other ways). However, you still end up with some pretty significant additional
heating and having microwaves absorbed by doing things like breaking chemical
bonds in the atmosphere probably isn't a great thing either.

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kirk21
Is it me or is this bull? You lose a lot of energy when you have to transfer
it back to earth... Just place the panels on earth already :)

Guess Elon Musk made fun of that before.

~~~
deeths
Not only losing the energy, but heating the atmosphere with it and drastically
adding to global warming. See my other response (which I didn't initially
realize should have been a response to your post).

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viame
Focus on Fukushima first, and many other things that are happening here and
need to be fixed, prior to solving world's energy problems and turning moon
into a solar panel. WTF is wrong with people.

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Amadou
They are going to need giant robots to build it.

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zerop
what are the main reasons they cant put the solar panel on earth (in japan).
earthquake??

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emp_zealoth
Available area which you can cover with the panels.

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orik
Not on our moon. How ugly.

