Space Based Solar Power

A new Pentagon study lays out the roadmap for a multibillion-dollar push to the final frontier of energy: a satellite system that collects gigawatts’ worth of solar power and beams it down to Earth.

Cool.

Step-by-step explanation of how it works:

* A network of satellites would be constructed in space with arrays of lightweight mirrors extending for several miles (kilometers) on each side.
* Those mirrors would focus sunlight on solar cells, generating electrical power. The electricity would be converted into microwaves suitable for transmitting through Earth's atmosphere, at frequencies of 2.45 or 5.8 GHz.
* The microwaves would be directed down to antenna arrays on Earth, as a beam of radiation about one-sixth as intense as noon sunlight. The antennas would convert the radiation back into electricity for distribution via conventional grids.

Darn, only 1/6 as intense as noon sunlight. There goes my Bond villain idea of using it as a death ray.

The real question is how the economics of such an endeavor would work and if this would be a better option than land based photovoltaics. I am skeptical, but it might work when you see the value to the military:

Those factors still don't make space solar power attractive for commercial users, but a better case could be made for the Defense Department. The U.S. military pays a premium for its power in the battlefield, when you consider the cost of shipping oil out of the Middle East, refining it, then shipping the fuel back to the combat zone and burning it in electrical generators, Miller said. All that brings the current power price tag to $1 or more per killowatt-hour, compared with 5 to 10 cents on the domestic market, the report says.

Could you imagine them using this in Afghanistan? They would be surrounded by people who still use livestock as a form of transportation, and here they would be fueling up their base and gadgets with solar power from a satellite in space.

via MSNBC via Engadget