Japan Plans to Have a Power Plant in Space in a Decade

Miles-long satellites covered in solar panels would collect energy from the sun and beam it down to Earth.

Artist concept of space solar power station. Image: Mafic Studios

Japan, where the disastrous Fukushima meltdown heightened the search for safe, sustainable alternative energy, is answering that need by sending a power plant into space.

Actually, the plan to power the globe with gigantic space-based solar panels has been kicking around since the '60s. But thanks to a perfect storm of technological advances—strong but lightweight tether materials, swarming worker robots that can self-assemble, more efficient solar panels, and cheaper payload launches—this thing is actually looking feasible.

JAXA, Japan Aerospace Exploration Agency, recently announced that it intends to stick a solar-generated power station in orbit for the first time by 2025—just over a decade.

Picture this: Floating 24,000 miles above the Earth's surface is a mammoth power plant (power satellite may be more accurate) that stretches several miles long, weighs 10,000 metric tons, and is covered with solar panels basking in the sun and storing up its powerful energy.

Image: Screenshot from JAXA/YouTube

The solar station is tethered to a base station on the ground with six-mile-long wires. This acts as a counterforce to offset the gravitational pull so the satellite is essentially pulled in tow as the Earth turns, keeping it at a fixed point in geostationary orbit. It’s the concept astrophysicists proposed to build our future space elevators, as explained Professor Emeritus at JAXA Susumi Sasaki in an editorial in IEEE.

The problem is that part of the Earth's rotation spins it away from the sun, which doesn't do much good for a solar power station. So the scientists hacked the initial model by adding in a couple mirrors to reflect the sunlight and point it directly on the panels, 24/7. These mirrors are just floating free, and scientists on the ground have to configure the whole setup with extreme precision.

Floating mirrors would reflect the sunlight onto the solar panels. Image: JAXA

That’s just the beginning of this multibillion-dollar challenge, however. After launching the station and mirrors up into the sky, the station then has to beam back energy to a small target on Earth, relying on wireless power transmission—something humans have been studying for decades but have yet to perfect.

According to the plan, the solar energy collected by the giant power satellite will be converted to microwaves, which are capable of traveling long distances while avoiding obstacles like weather and debris. The microwaves are beamed down to a receiving site on the ground speckled with antennas, where it's converted to electricity.

The planned space-based station can process 1 gigawatt of power, on par with the nuclear plants here on the planet. But it can do this ostensibly indefinitely, as long as the machinery (and the sun) hold out.

Solar panels in space are up to 10 times more efficient than the ones we've got on Earth, so the potential is beyond intriguing. If JAXA's or other current plans to build space-based solar power stations work—and according to the JAXA site, "we are getting close to the stage where it is feasible"— that could be a revolutionary change for society. A lot of industries would be turned on their heads.

In a blog post on the World Future Society, futurist Thomas Frey speculated that once one orbital solar station proves to be successful, other nations with space programs would rush to launch power plants into space, too. He believes the JAXA project marks the beginning of the next space race.

Maybe it could be: Energy is one of the most pressing issues of our generation, and probably the generation after that even more so. At the dawn of the space exploration age and peak techno-optimism, the temptation to look for an answer in the skies makes sense.

Right image: JAXA