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Lunar Power
An Anonymous Coward cites this article on ABC News, excerpting: "...the world would have access to a limitless power supply. The moon receives 13,000 terrawatts of power from the sun. Harnessing 1 percent of that energy, he calculates, could replace all fossil fuel power plants on Earth."
So, the moon receives 13000TW of power, and we only need 1% of that? Let's do a little math eh...
Solar cells are at best about 20% efficient. For the sake of my argument, that's the number I'm using. The argument stands even if you could imagine getting 50% efficiency from the falling sunlight.
They would need to cover 1% of the lunar surface on BOTH sides of the moon, because only half of the solar panels would be in sunlight at a time.
They would need to cover 5% of the surface, because the cells are only 20% efficient.
Combine those two problems, and you have 10% of the surface of the moon covered in solar panels. Add another 5% because not every portion of the surface is suitable for placing panels. Multiply the result (15% of the lunar surface covered) by about 1.5, to make up for the transmission loss from the moon to earth, and through the atmosphere. Result... over 20% of the moons surface, its TOTAL surface both visible and non, covered with solar panels to get that 130TW the author stated.
Imagine the moon with a bright shiny ring of solar sails all along the left and right edge. If you can't hear every environmentalist and presevationist crying out simultaneously in anger, you are deaf.
"I will trust Google to 'do no evil' until the founders no longer run it." Hello Alphabet.
First of all, that darn atmosphere absorbs a lot of it. Second, that's the energy that keeps you warm and feeds you (plants don't live off of love, you know).
The only way the moon as power source will be practicable will be if we move up there or figure out how to get that energy down here. Neither one is any easy task. You can pretty much forget about the first, and the second involves crazy plans with microwaves. What happens when the aiming device gets hit by a meteor, and the microwaves fry some poor shmuck? oops. Not to mention the amount of power that such a system would lose sending the signal through the atmosphere.
The only way I see space based power being practicable is with some sort of geo-synchronous elevator (the ones that are connected to the planet by a metal cable in sci-fi). Then you could put solar panels, fission/fusion or pretty much any other type of power plant up there, and just let the wires carry it down with a whole lot less risk than a microwave beam.
Don't hold your breath for any practicable space based power in our time, though.
BlackGriffen
Funny you should mention this. Did you know you can get an approximate figure of the speed of light using only a common microwave oven, marshmallows and a ruler? Try this experiment:n 34/marshmal.htm
http://www.physics.umd.edu/ripe/icpe/newsletters/