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> I can cover the entire surface of the earth with solar panels to harvest the moon light

Are you sure about that? First off, take an off-the-shelf solar panel, point it at the moon in the middle of the night. You get a grand total of nothing. Okay, it was a cheap panel, that might not generalize to anything.

But more importantly, by the argument laid out in the article, your solar panels cannot work in moon light. (Or maybe they work at horrible efficiency, because the moon is a bit warmer than the earth.) I'm not sure I buy that argument; maybe you should run the experiment.

There is no need for an experiment, the moonlight does produce energy in a solar panel. Obviously the power produced will be much much lower than with the sun. I remember that as a child I was able to use a solar calculator indoor with just the power gathered from an incandescent light.

>(Or maybe they work at horrible efficiency, because the moon is a bit warmer than the earth.)

Yes, this is what would happen.

I'll repeat for the reflexive downvoters:

Solar panels will work in moonlight if and only if you can make fire from moonlight with a magnifying glass.

The answer depends on how good a mirror the moon is. It calls for a real experiment, not a thought experiment. I don't really know which way it will go.

You're not addressing the essential part of my comment. Let me clarify:

I put in place 1000 solar panels and aim them at the sun thus procuring 200kw of power. Next I use it to power an arc welder, producing 10,000 C of heat. Therefore I have used a 6,000C sun to produce 10,000C on earth.

Would a similar setup work with the moon? I don't know. That was not my point, my point was that it certainly is possible to produce higher temperature at the target than it was at source.

Monroe’s explanation only applies to optical systems, ie reflecting and focusing light, which is a thermodynamically reversible process (yes, even with dust. Dust doesn’t make the lens thermodynamically irreversible, it just scatters and absorbs some of the light so it doesn’t reach the lens. The irreversibility is a property of the lens). Solar panels are converting light energy into electrical energy, which is not an irreversible process - it creates entropy, and therefore the rules are different.

Sure it is, just not in real-time. The lense fails because there is no storage mechanism.

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