Power From Space

If you’ve ever played any of the popular “Sim City” games, you’re already familiar with the concept of Orbital Power or Microwave power, as it is sometimes called. For those who don’t waste their time playing video games, Microwave power systems use large banks of solar panels placed in geostationary orbit, which then beam down power to the Earth’s surface in the form of extremely high frequency microwaves. It’s an old idea – it has turned up in Science Fiction stories and novels repeatedly since the first solar panels went to space in the 1960’s – but until recently the technology has not been available to make this sort of thing a reality. There have also been persistent (and usually fatuous) scare rumors that the microwave beam might “wander” from its receivers and accidentally charbroil large patches of the Earth’s surface. Today’s story on MSNBC suggests that both problems may now be in hand

Curiously enough, it would appear that the U.S. Military is the key customer who could make all of this go – an ironic twist, given that the initial exploration of space that led to the use of solar panels to power long-duration spacecraft was made using rockets adapted from military ICBM designs. It turns out, however, that the Pentagon really likes the idea of getting between 10 and 50 megawatts of energy (enough to operate a small military base, including things like radar and motion sensors) beamed directly to wherever it wants to put a base, without inconvenient details like having to ship in electrical generators and then keep them supplied with ridiculously expensive and absurdly vulnerable fossil fuels.

The story cited above notes that today’s solar power cells are about three times more powerful than those of only 10 years ago, and the experience obtained from building and operating the International Space Station should make construction of the first power satellites feasible, if still not exactly cheap. Construction cost on the first unit is projected to cost on the order of $10 billion, which sounds pricey until you realize that unlike a fuel-burning power plant, the energy from the orbital system is effectively free once you’ve completely the construction. By my calculations, the system described would take about 20 years to pay for itself (assuming 50 megawatts generated, and using California pricing for electricity), but with no onboard reactor and no moving parts there is no reason to believe that these systems wouldn’t live up to the typical 50-year service life of long-duration space systems. If the price of fossil fuels continues to rise (and it’s a fair bet it will) that breakeven point comes a lot faster.

More to the point, perhaps, larger power arrays in orbit would be much more powerful (as much as 10 gigawatts per unit) and considerably more efficient. And, unlike terrestrial power technologies, orbital power units do not create air pollution, water pollution, noise pollution, or radiation hazards, or take up large patches of environmentally sensitive real estate. There are still a lot of details to be worked out, of course, but once we get the defense contractors on board, the rest should be a slam-dunk. Face it, folks, in this country the Military-Industrial Complex generally gets what it wants, and there’s no denying how useful this would be for national defense, both directly and in the strategic reduction in reliance of foreign oil production.

Now if we can just get the Pentagon interested in funding breakthrough technologies in other useful areas, like education or healthcare…