California gives green light to space-based solar power project
Dec 4th 2009 4:30PM
Updated Dec 5th 2009 9:34AM
The concept is not new. Satellites orbiting far enough outside our atmosphere can capture solar energy around the clock, and without power-reducing cloud cover or atmospheric interference. The satellites use photovoltaic panels, much like those that are installed on ordinary buildings, to capture solar energy and convert it into electricity.
What happens next, though, is a bit different than what occurs on your average rooftop: The electricity is used to generate microwaves, which are beamed at large antennas on Earth. The antennas recapture the energy of the microwaves and convert it back into electricity. It all may sound like science fiction, but space-based power appears to be quickly moving towards reality.
And Solaren isn't the only one in the race: Other companies are also pursuing space-based solar power. A consortium of Japanese firms and the Japan Aerospace Exploration Agency unveiled plans in early September to build a 1-gigawatt solar power collector in space. That project, which would beam down enough power to supply hundreds of thousands of homes, will cost well north of $20 billion. They hope to start sending parts of the system skyward in 2015, with their eyes on a completion date in 2030.
Solaren has been working towards space-based power since 2001. Under the current plan, a constellation of four Solaren satellites would use a new type of concentrated photovoltaic cells to absorb the Sun's rays, convert them into electricity in space, convert that electricity into microwaves, and beam the power down to a remote location outside Fresno. There, sensors would collect the microwaves and convert them back into electricity. Before getting CPUC approval, Solaren secured a power producing agreement with PG&E in April 2009.
No Danger To People, Birds or Planes
PG&E hasn't put any money into the project and doesn't plan to. Needless to say, this is a risky venture. But according to Solaren, the primary risk at this point is really in the launch, not in the technology.
"The technology is fairly well developed. If you look at today's communications satellites, they have solar cells that generate the electricity they need. These satellites convert the electricity into radio waves, then signal to your home to your television. That's what DirecTV does. Except unlike them, we don't throw away the center part of the beam where all the energy is located," Solaren's Director of Energy Services Cal Boerman told me in an interview two months ago.
Solaren might face some questions from the folks in Fresno who will be on the receiving end of those microwave beams, but Boerman explains that the energy beam won't even register with birds, people or passing planes.
"The energy levels we'll be working with are a lot less than you might feel if you were sitting out in the midday sun, because the beam will be spread out over a very wide area. The receiving antenna on the ground will be a couple of square miles. It's a big area, but that means the beams are at lower concentration. As for airplanes, they would feel more heat coming out from under clouds than they would entering our beam. Remember, the satellites are 22,000 miles up, far above where planes or birds fly. We're so high up that even space junk is not an issue," says Boerman.
It's still very early days for this Star Trek-esque technology, and it remains to be seen whether Solaren or any other company can mount a space power effort that actually provides power at a competitive rate. Best case scenario, this is a slam dunk and we move large chunks of power generation into orbit and away from the Earth. But don't expect a scenario like that to play out for at least another 30 years.
Alex Salkever is Senior Writer at AOL Daily Finance covering technology and greentech. Follow him on twitter @alexsalkever, read his articles, or email him at firstname.lastname@example.org.