Why not use the moon for energy?

  • Thread starter Experimenter
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  • #1
Experimenter

Main Question or Discussion Point

Why not build an enormous solar collector panel on the moon and use it to harvest energy and somehow bring it back to earth? Is it the cost of the undertaking?

Experimenter
 

Answers and Replies

  • #2
mathman
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Getting the energy back to earth would be extremely difficult. It would be a lot easier to place solar panels in various desert areas (U.S southwest, Sahara, Kalari, Arabia, Gobi, etc.) on earth.
 
  • #3
LURCH
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Originally posted by mathman
Getting the energy back to earth would be extremely difficult. It would be a lot easier to place solar panels in various desert areas (U.S southwest, Sahara, Kalari, Arabia, Gobi, etc.) on earth.
Or even just to place them in orbit around the Earth, if you're talking about the advantages of no atmosphere/no night.
 
  • #4
bleh
microwaves

if you could set that up on the moon could you use focused microwaves to send the energy back to earth ive always wondered about something like that aswell

thanks
 
  • #5
Foraker
well i think solar panels usually charge up batteries for power, if you put panels on the moon, and use microwaves to send the energy back you could only be getting energy half the time. So you solve that you make the moon send it to a sattleite in geosynchronus orbit to power that and then send power back to us. But i dont think it would be worth it, since no one part of the moon is always pointed at the sun, you would only get a half cycle. So you would only get around 15 days a cycle when the panels are in the sun.
 
  • #6
HallsofIvy
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But just think how long the electric cables would have to be!
 
  • #7
kauai_diver
When I first saw the topic of your post I thought of tides. Is there such a device that uses the tides caused by the gravitational field of the moon to produce energy? Not talking dams or the like, just using tidal motion to produce energy.
 
  • #8
Phobos
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Certainly a major (but feasible) engineering undertaking which would require a lot of political motivation (which is not there at the moment).
 
  • #9
enigma
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Building solar panels on the moon isn't that great an option. The moon has a 28 day rotation. Any panel would be active for 14 days and then inactive for 14 days. Couple that with several hundred degree temperature shifts from day to night, and you'd have big problems keeping the array in operation for very long.

An orbital array is more feasible, but there is still a fairly large problem with maintenance. When the cells burn out, replacements would need to be brought up from the surface at $10,000 per pound, and then you'd still need to get a working repair craft to do the fix (which could also break down).

It's possible, but not very practical until we either get construction facilities in orbit for replacement parts or the launch costs drop dramatically.
 
  • #10
bleh
tides

popular science had an artical about a new way to collect energy from tides i thought it was pretty interesting, i tried finding the artical online but couldn't hope you have more luck, i thought it was really interesting

bleh
 
  • #11
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Originally posted by kauai_diver
Is there such a device that uses the tides caused by the gravitational field of the moon to produce energy? Not talking dams or the like, just using tidal motion to produce energy.
See here:

http://acdisweb.acdis.uiuc.edu/NPRE201/fall02web/webpages/barthel/tech.html [Broken]
 
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  • #12
drag
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Originally posted by bleh
popular science had an artical about a new way to collect energy from tides i thought it was pretty interesting, i tried finding the artical online but couldn't hope you have more luck, i thought it was really interesting
Yeah, I saw that one too. But it's not like I din't
think of it before either. It's really the simplest stuff
that even any kid can think of. Funding the consturction
is a different issue. For example, wind turbines could
easily supply all the power needs of the world and they
operate all the time so any country can build them separately
and would just have to make sure it has enough of them.
The construction could easily be managed over the course
of several years so that it would actually cost nothing
at all because the new savings due to the turbines constructed
each year would make up for the costs of their construction
the year before. Once they supply the majority of the
energy a country requires the financial gain, if other countries
are still using fossil fuels or even nuclear plants, would
be enormous since the turbines only require a bit of maintaince
and nothing more. Why isn't being done ? Because an energy
revolution like this in even just one small country will
greatly affect the world's political and mainly economical
arenas and power distribution and the ones in control
today wouldn't like that to happen.

Live long and prosper.
 
  • #13
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Mathman's alternative of making
use of desert areas right here
on earth would be much easier
and cheaper to implement.
From what I understand, solar
to electric panels are still
too expensive for this to be
competitive with conventional
generating systems.
There is a geothermal plant
here in Southern California that
takes advantage of an area of
thin crust to send water down
into the earth where it's heat-
ed to 300F and comes back up
as steam to run turbines.
A person can make a solar oven
that will get up to 300F from
a cardboard box, aluminum foil,
and a pane of glass. Seems to
me it would be a cinch to engineer
a steam generating plant to be
powered by the desert sun. The
water would be used over and over.
-zoob
 
  • #14
mathman
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if you could set that up on the moon could you use focused microwaves to send the energy back to earth ive always wondered about something like that aswell
How do you expect to keep the microwaves focused on the receiver? The earth is rotating!
 
  • #15
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Being powered by the tides may seem like a good idea, but they change the environment just as much as anything else. I think Hawaii has tidal generators, but their power comes from the orbiting of the moon. As it is the moon is receding, causing the precession of the earth to become more chaotic, and tidal generators make it worse. It'd be a billion years before anyone notices, but I think tidal power could unnessecarily shorten Earth's habitable lifespan.
 
  • #16
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Originally posted by enigma
Building solar panels on the moon isn't that great an option. The moon has a 28 day rotation. Any panel would be active for 14 days and then inactive for 14 days.
I thought about this at first too, but then i figured out this idea is pointless.
On earth the same thing happens, the panels work only for 12 hours out of 24 (depending on where you are on earth of course, but i mean in average), which is the same as 14 days/28 days (and btw, as far as i know the moon takes 29.5 days for a full rotation, not 28).
Or .. am i missing sth ?
 
  • #17
bleh
Originally posted by mathman
How do you expect to keep the microwaves focused on the receiver? The earth is rotating!
it would bounce off satellites that are rotating around the earth aswell when the receiver was farthest away from the moon as possible it might have to bounce off 2 satellites to make it to the reciever it could be done

bleh
 

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