In the wake of the Fukushima disaster, Japan has doubled its efforts to find a viable alternative to nuclear power. An updated proposal from the Japan Aerospace Exploration Agency (JAXA) seeks to solve the island nation's energy woes — and it's the much vaunted scifi-like idea of building an orbital farm.


Space-based solar is an incredibly promising hi-tech solution — one that could potentially solve all our energy needs. Though many different ideas have been proposed, the basic concept remains the same: Set up large photovoltaic platforms in Earth's orbit and beam the extracted energy down to receiving stations back on land in the form of microwaves that can be converted into electricity.

JAXA has now devised a sophisticated scheme for doing so, and it sounds absolutely mind-blowing. They've devised a road map that describes a series of ground and orbital stations leading to the development in the 2030s of a 1-gigawatt commercial system — which is the same output as a typical nuclear power plant. Prior to this, they'd like to set up a 100-kW SPS version around 2020.


Writing in IEEE Spectrum, Susumu Sasaki describes what it would look like:

Imagine looking out over Tokyo Bay from high above and seeing a man-made island in the harbor, 3 kilometers long. A massive net is stretched over the island and studded with 5 billion tiny rectifying antennas, which convert microwave energy into DC electricity. Also on the island is a substation that sends that electricity coursing through a submarine cable to Tokyo, to help keep the factories of the Keihin industrial zone humming and the neon lights of Shibuya shining bright. But you can't even see the most interesting part. Several giant solar collectors in geosynchronous orbit are beaming microwaves down to the island from 36,000 km above Earth.

To get there, JAXA will have to garner the help of an international consortium, like the ones that fund the world's giant particle physics experiments. As Sasaki notes,

It would be difficult and expensive, but the payoff would be immense, and not just in economic terms. Throughout human history, the introduction of each new energy source—beginning with firewood, and moving on through coal, oil, gas, and nuclear power—has caused a revolution in our way of living. If humanity truly embraces space-based solar power, a ring of satellites in orbit could provide nearly unlimited energy, ending the biggest conflicts over Earth's energy resources. As we place more of the machinery of daily life in space, we'll begin to create a prosperous and peaceful civilization beyond Earth's surface.


Sasaki goes into great detail about the JAXA plan at IEEE Spectrum, so be sure to read the entire thing.

Image: John MacNeill via IEEE Spectrum.