One need not venture to the Cave of Wonders to discover the magic of flying carpets. The Space Solar Power Initiative (SSPI), a collaboration between Caltech and global security company Northrup Grumman, has proposed the development of solar paneled “flying carpets,” each nearly the size of a football field, that would orbit in sync while gathering energy. This interstellar solar energy would then be beamed down to the planet to provide clean power across the globe.
When the proposed 2,500 solar carpets are installed in orbit, they will cover an area of 3.5 square miles – though only an inch thick. The solar carpet constellation would be especially useful to provide power to impoverished, rural areas. In places where electrical infrastructure is nonexistent, “it’s easier and more economical to deploy a wireless network there,” says Caltech researcher Ali Hajimiri. To avoid occupying already scarce space, the energy receivers could be built upon already existing buildings or even attached to chicken wire over farmland.
The energy would be safely beamed to Earth in the form of microwaves, which would then be transformed into electricity on planet. “The energy density you are transmitting is no more than what you get by standing outside in the sun or using your cell phone,” says Hajimiri. “It can’t induce chemical change, it can just generate slight heating.” Solar panels constantly re-positioned in space where needed would also be more effective harvesters of solar energy than terrestrial plants. “You look at the seasons, day-night cycle and all of that versus having it in space at geostationary orbit (an orbit where a satellite appears to hover over one spot on Earth’s surface), and there is an advantage in space, factor of 9,” says Caltech researcher Sergio Pellegrino.
The Caltech team acknowledges the challenges ahead of them, but are confident that their pursuit is a worthy and achievable goal. “We’re talking about building a new industry, to be sure,” says Caltech researcher Harry Atwater. “But it’s not a pipe dream.”