Focused Microwaves Could Enable Wireless Power Transfer 180
esocid alerts us to news out of the University of Michigan, where physics researchers have found a way to focus microwaves to a point 20 times smaller than their wavelength using a new 'superlens'. Such resolution was thought to be impossible until recent years, and it could bring about the capability to transfer power wirelessly.
"No matter how powerful a conventional lens, it cannot focus light down to more than about half its wavelength, the 'diffraction limit'. This limits the amount of data that can be stored on a CD, and the size of features on computer chips. The new lens is a 127-micrometer-thick plate of teflon and ceramic with a copper topping. 'The beauty of these is that they're planar,' Grbic says, 'they're easy to fabricate.' The lenses can be made through a single step of photolithography, the process used to etch computer chips."
Re:Never mind the power thing (Score:3, Interesting)
Comment removed (Score:4, Interesting)
Actually it was a very GOOD idea but NASA blew it. (Score:5, Interesting)
Actually it was a very GOOD idea. But NASA blew it.
The plan was to site solar power satellites in geosync orbit and bring the power back via microwaves.
Unlike microwave ovens (which are tuned to a frequency that is strongly absorbed by water), these would be tuned to a frequency where water - clouds, rain, birds, cows, people - is essentially transparent. This is good both for getting the power through the atmosphere and avoiding rains of roast duck.
I could go into detail on why there's no problem from the millimeter waves, but that would take time. Short form: System failures defocus the beam so much it becomes just radio interference in directional antennas pointed at the satellites. Even when fully focussed it's not an issue for tissue: You can grow crops and graze cattle under the (rather spindly) rectennas, so they don't even use up the chunk of land they're on.
Benefits:
- Enough power to completely replace fossil fuel AND nuclear plants and absorb forseeable energy use expansion for decades.
- 'Way cheaper, too. (Even at '60s fuel prices.)
- Essentially no pollution at ground level.
- Bootstraps a space program that can then move other manufacturing processes, and THEIR pollution, off the planet as well.
NASA blew it by doing a study that purported to show it would be too expensive. But they did that by splitting the design teams for the rockets and the power plant. The power plant designers made a turbine very large to get a couple extra percent of efficiency. Then the rocket designers came up with a heavy lifter sized to take the biggest piece. Result: Enormous rockets with few trips to ammortize the design/construction costs, rather than moderate sized ones with many trips. Cost skyrockets versus a properly integrated design with a small turbine and a fleet of smaller lifters.
Re:We tried that (Score:5, Interesting)
On the other hand, if you beam the energy down, you will have much lower losses provided the atmosphere is transparent at the wavelength you use to send the energy. All you will get from beam spread will be a lower energy density but the same total amount of energy (aside from absorption and scatter losses) will be available.
Beaming power down is probably a much more efficient way to go depending on conversion losses at the source, the scatter and absorption losses, and the conversion losses again at the receiver.
I don't know about the efficiencies and losses of beaming but would guess they would be much less than however many miles of cable would be required and would bet the cost would be lower as well.
You would just need to make damn sure you switch the beam off if it quits tracking the target receiver. Bu as the other person commented, I think this isn't intended to beam power from space.
Re:We tried that (Score:4, Interesting)
To a certain extent, the effect will be the exact opposite of what you are thinking, as the sunlight would have most assuredly heated the land, sea and air, but beamed down to the electrical grid, it will be stored in other forms, such as the potential energy of a high-rise building, or in places where the increased warming isn't terribly important, like the area immediately around a ski lift.
Re:We tried that (Score:2, Interesting)
For *any* wire, even if it was made out of a really good conductor like gold, there is always some distance where the losses become greater than that of wireless transmission at the same distance.
Re:Nothing new here; still not a good idea (Score:1, Interesting)
Re:We tried that (Score:3, Interesting)
Re: Not likely to happen (Score:3, Interesting)
Doesn't anyone here get it? (Score:4, Interesting)