Not for power satellites, but for powering or charging local devices, like cell phones. It doesn't say what the efficiency is, though.

this is news ?
Japanese have been doing lots of experiments with microwave power transmission, including flying model airplanes with microwave power.
Look at http://www.kurasc.kyoto-u.ac.jp/jusps/KA-1.pdf

http://www.kurasc.kyoto-u.ac.jp/plasma-group/sps/milax-e.html

Kyoto university has always had ongoing research programs on WPT. AFAIK, they have achieved around 80% overall transmission effiency.

40% efficient

this is news ?
Japanese have been doing lots of experiments with microwave power transmission

Read the freakin' article:

Various methods of transmitting power wirelessly have been known for centuries. Perhaps the best known example is electromagnetic radiation, such as radio waves.
...
In contrast, WiTricity is based on using coupled resonant objects.

Those evil Halliburton-funded scientists just want to put extension-cord makers out of work.

I wonder whether there is a way to change the characteristic/resonant frequency over time so that only a properly matched device could absorb the energy?

This seems to be needed to prevent unauthorized energy absorption, or else you might people at Starbucks with four or five laptops and assorted cell-phones charging up for free. Also it might mitigate the biological effects, just in case you start growing a tumor that has the same resonant frequency! Maybe, the emitter and receiver can be paired up, as in a bluetooth pairing, with a secure code that defines the frequency variation?

Yeah Toast. I can see the economics of this being very challenging. In public spaces you'd want to know who pays for the power usage. Even in the home you'd have the potential for neighbors tealing your power (much like you can do with wireless internet now).

Can the resonance be tuned to frequencies that get absorbed rapidly in the atmosphere? That would restrict the scheme to short / near contact ranges, thereby avoiding power siphoning.

Hmmm. Power siphoning. Sounds like the basis of a Sci-Fi / Horror flick.

I am thinking of (say) a desk surface that has embedded emitters, and a resonant coil in (say) a laptop. While on the desk, the resonant coil charges the battery, which runs the laptop.

Anyone?

MG, the article addresses this..

With such a design, power transfer has a limited range, and the range would be shorter for smaller-size receivers.

My guess is that the resonant frequency is higher and the range lower as the the geometry shrinks. Again, what might really help is if you could control the effective geometry and thereby the frequency via software.

TnT,

Thanks. I reckon RTFA is pretty much always a good course of action, eh?

Here's more detail:

http://arxiv.org/ftp/physics/papers/0611/0611063.pdf

McGehee: Those evil Halliburton-funded scientists just want to put extension-cord makers out of work.

Halliburton doesn't fund scientists, it funds Republicans.

Toast: I wonder whether there is a way to change the characteristic/resonant frequency over time so that only a properly matched device could absorb the energy?

There's an entire class of "resonance weapons" under development, but most of them involve pressure waves. Do you suppose this could eventually become applicable?

Halliburton doesn't fund scientists, it funds Republicans.

They're plotting to put the extension-cord industry out of work. Obviously they're Republican scientists.

Man this would would be a way to bring power to the people, man, to give them what truly belongs to them by birth right. FREE POWER TO THE PEOPLE!

But you know, man, that since this is run by Halliburton, man, that they are just gonna fund their secret society of Atomic Super men, man. They are gonna invade us on their electro-statically charged floating battle blimps and evaporate the non-believers, the environmentalists, and the conspiratorists with their plasma energy beam weapons. Tesla predicted all this man, and Nostradamus, he saw it happening too in his bubbling pot of soothe sayer water, man.

Obviously they're Republican scientists.

And I thought they were Amish astronauts.

Wireless Power Transfer News, Experimental Videos And Information:
http://www.witricitynet.com