The next step, expected around 2020, would be to launch and test a large flexible photovoltaic structure with 10 megawatt power capacity, to be followed by a 250 megawatt prototype.

JAXA says the transmission technology would be safe but concedes it would have to convince the public, which may harbour images of laser beams shooting down from the sky, roasting birds or slicing up aircraft in mid-air.

Most of that energy will be lost in transmission. No beams can penetrate tick clouds. Can't we see it on satellite TV?

So far we are not collecting solar power here, on Earth...

Sorry for disappointing you again, dear... ((( ))

That's not quite correct, aklimento. Microwaves can penetrate clouds, haze, dust and all but the heaviest rainfall. .

(They use microwaves to measure sea surfaces temperatures, the extent of sea ice etc, from satellites, too. )

Laser beams can't normally penetrate thick clouds, because they scatter, but it's been shown that this scattering can be overcome, by using high-intensity ultra short pulses.

(A research group at the Laboratory of Molecular and Ionic Spectroscopy (LASIM) at Université Claude Bernard (Lyon, France) has demonstrated that the stable light filaments generated by such pulses can maintain themselves and overcome heavy scattering through a substantial fog. (Appl. Phys.
Lett. 2003, 83, 213)

Microwaves can penetrate

Yep, they can, no question about it. But by what rate? 3-5%? Is it worth it?

Is it worth it?

Last month Japan's Economy and Trade Ministry and the Science Ministry took another step toward making the project a reality, by selecting several Japanese high-tech giants as participants in the project.

The consortium, named the Institute for Unmanned Space Experiment Free Flyer, also includes Mitsubishi Electric, NEC, Fujitsu and Sharp.

These guys apparently think so. .

Who will let them to do this? What if this energy beam will be directed (intentionally or accidentally) to a wrong target? Dangerous sci-fi games. They cannot shot down a rocket with similar laser cannon so far...