Law of Unintended Concequences

Simple problems have simple solutions, right?

I'd like to apply this logic to global warming, and one of the great saviours of the planet, if you listen to Internet Inventor Al Gore: Solar Power.

Now, I'm not an expert sceintist, but I do understand enough to find a flaw in the idea of replacing a huge chunk of our power production with solar power. And the problem has nothing to do with the huge amounts of the Earth's surface that would be required.

What the problem has to do with is basic Thermodynamics. When a system is in equilibrium, energy in = energy out. If you decrease the energy out, then temperature goes up until a new equilibrium is established.

So, Solar Power fanatics want to collect anywhere from gigawatts to terrawatts of solar power to run our toasters and electric cars, right? Where does that energy come from...remember that the law of conservation of energy means that you can neither create nor destroy energy (as modified by Special Relativity, you can convert energy into matter, and vice versa, but that's an extraordinary situation to be sure).

Ever look at a photovoltaic cell? They're very, very dark. Large quantities of them, covering a sizable percentage of the Earth's surface, would have the effect of changing the Earth's reflectivity to sunlight. Viewed from outside, the Earth will look darker than it is now. That means that more sunlight is absorbed at the earth's surface. That would have the effect of reducing the amount of sunlight that is reflected by the Earth into space, and that brings us back to the energy in=energy out equation. We'd be reducing the energy out from the Earth...and under basic thermodynamics, the temperature of the Earth would need to rise until a new equilibrium were met.

Now, I know the principles here, but the math is beyond me. There has to be someone out there who can crunch some numbers for me...here's some basic facts:

In 2005, worldwide generation of electricity was 18,184 TWh (BP Statistics). Can anyone tell me how much sunlight would need to be captured to create each 1% of that amount? What % of reflected sunlight would we capture to replace it all?