Space-based solar power: Here's how it could work

When we talk about space, it’s easy to get ahead of ourselves. Though there’s not as much money going into NASA anymore, there’s still plenty of innovation in the field of space research. Many people may not know it, but space research includes cleantech. A little bit of Googling, and you’ll find that there’s quite a bit of talk — and R&D — about the potential for space-based solar power generation.

That is, after a few decades, a few billion dollars, and a few new technological discoveries, of course.

It’s all a bit far-fetched, but it’s fun to imagine. Check out these seven facts about space-based solar power.

1. NASA has been talking about solar power in space for decades.

Since the 1970s, to be exact. It was a decade after Apollo 11 landed on the moon, and NASA planned to build a space-based solar factory because of the energy crisis on Earth, and because they were dreaming pretty big at the time. Of course, it never came to fruition, but the idea that NASA could do something for cleantech and in the solar arena lingers.

2. There’s a new technology that cools solar panels by reflecting heat into the universe.

The more heat solar panels absorb, the less efficient they become. So Stanford researchers came up with a new technology: a thin layer of silica that overlays on solar cells that captures and emits thermal radiation from infrared rays, into space, to cool them off and boost efficiency. According to a statement from Stanford, when the overlay was tested, it cooled the absorber up to 23 degrees Fahrenheit.

3. Researchers are working on solar cells to use in space missions.

At the University of Arkansas, researchers are working to develop the next generation of photovoltaic technology for space. The project is with NASA, who recently recognized the university’s material science research. According to a press release, the new material is supposed to “boost performance, helping NASA achieve its 15-year, 45-percent efficiency goal for solar devices” and ”lower the cost of manufacturing and make the devices more radiation tolerant.”

4. The Department of Energy has a website dedicated to the idea of space-based solar power.

They even have an acronym for it (SBSP). The concept of solar arrays in space that catch light is still very sci-fi-like, but there is potential for it. About 30 percent of solar doesn’t make it to Earth, and is reflected back into the atmosphere, and in space, there are no clouds, no atmosphere, and no night.

5. Scientists already have an idea how a space-based solar farm would work.

Last year, the US Naval Research Laboratory announced that Dr. Paul Jaffe, a spacecraft engineer, built a module to capture and transmit solar power. The idea is that a solar power satellite could transmit much cheaper electricity to the grid on Earth. Jaffe refers to the module he created a “sandwich module.” This is how it works: the sun sends out photons, and reflectors concentrate those photons on the sandwich module. The top, with the solar array, collects to energy, and electronics in the middle turn it into a radio frequency. Antennas beam that to Earth, and then they’re converted back into electricity and sent to the grid.

6. China may be building a solar power station in space.

Earlier this year, Chinese scientists announced they are building a solar power station in space, with an experimental one done by 2030 and a viable one completed by 2050. They said it could harness the sun’s energy almost all of the time and transmit it back down to Earth. Of course, the biggest hurdles include making panels light and cheap enough to get up there, and then finding something to transport them to build it.

7. Japan successfully tested a system that could transmit solar power from space to Earth.

Mitsubishi Heavy Industries tested the solar power system at Japan Space Systems, and saw 10 kilowatts were sent over microwaves to a receiver about 1,640 feet away, though the company never announced what percentage that was of the total power sent.

http://www.forbes.com/sites/lyndseygilpin/2015/09/25/space-based-solar-power-heres-how-it-could-work/2/