Japan's space agency planning space-based solar power arrays

[Carlos_E]

For decades, scientists have explored the possibility of using space-based solar cells to power the Earth. Some see orbiting power stations as a clean and stable energy source that promises to slow global warming, while others dismiss the idea as an expensive and impractical solution to the world’s energy problems. While the discussion goes on, researchers at the Japan Aerospace Exploration Agency (JAXA) have begun to develop the hardware.

JAXA, which plans to have a Space Solar Power System (SSPS) up and running by 2030, envisions a system consisting of giant solar collectors in geostationary orbit 36,000 kilometers above the Earth’s surface. The satellites convert sunlight into powerful microwave (or laser) beams that are aimed at receiving stations on Earth, where they are converted into electricity.

On February 20, JAXA will take a step closer to the goal when they begin testing a microwave power transmission system designed to beam the power from the satellites to Earth. In a series of experiments to be conducted at the Taiki Multi-Purpose Aerospace Park in Hokkaido, the researchers will use a 2.4-meter-diameter transmission antenna to send a microwave beam over 50 meters to a rectenna (rectifying antenna) that converts the microwave energy into electricity and powers a household heater. The researchers expect these initial tests to provide valuable engineering data that will pave the way for JAXA to build larger, more powerful systems.

JAXA says the orbiting solar arrays, which have the advantage of being able to collect energy around the clock regardless of the weather on the ground, will need to transmit microwaves through the earth’s atmosphere at frequencies that are not affected by the weather. The researchers are now looking at using the 2.45GHz and 5.8GHz bands, which have been allocated for use with industrial, scientific and medical devices.

JAXA ultimately aims to build ground receiving stations that measure about 3 kilometers across and that can produce 1 gigawatt (1 million kilowatts) of electricity — enough to power approximately 500,000 homes.

http://www.pinktentacle.com/2008/02/...-power-system/

[Carlos_E]

When the array fries a major US city they'll just claim it was an accident.

[Tock]

When the array fries a major US city they'll just claim it was an accident.

I don't know about microwaves; is such a thing possible?

[Logan13]

When the array fries a major US city they'll just claim it was an accident.

It is nice to see at least someone pursuing new energy technology, but it does remind me of an "Austin Powers" movie where it was indeed used as a weapon.

[Kärnfysikern]

Its a damn cool idea. Its been circulating for a while among geeks

The problem is offcourse the insane expenses in putting things into orbit, especialy to geosync orbit. If we could manufacture things in orbit from materials from captured asteroids or perhaps on the moon it could maby be economic.

[Flagg]

I like the sounds of this. I like it a lot infact. Sure it's expensive, prehaps if developed countries could stop spending billions on the military for a change...

Nuclear stations on Mars, planned trips to Mars, plans to teraform....it seems we could be entering a new Space Race era

[Kärnfysikern]

Nuclear stations on Mars, planned trips to Mars, plans to teraform....it seems we could be entering a new Space Race era

There is plenty of vision But unfortunaly no one is putting money into it