Technical peeps

[wiffleball 4,796]

http://www.foxnews.com/story/0,2933,301479,00.html

 

Okay, so they're talking about collecting solar power and beaming 5-10 megawatts back to the earth. Seems like a fine idea I s'pose. Except:

 

 

1) Since when were we able to beam electricity without wires? and:

 

 

2) Wouldn't that be a little dangerous to have a 10 megawatt beam shooting down on us? I'm fairly certain that if I can't use my cell phone on a plane without fear of apparently bringing the thing down, that 10 megawatts shooting through the focker would be substantially more dangerous.

 

3) It's a geosynchronous - not geostationary - orbit. I mean assuming we're timing the power bearming (and not just cutting a swath of destruction across the earth), if you're off by a second or two on that, we're talking major league damage.

 

anybody ever heard of this idea?? The miitary's on-board with it, so it finally stands a chance of getting some funding, but still...

[Strike 5,941]

It's something that's been discussed for decades. Very feasible and should be very efficient and environmentally friendly. As to your questions:

 

1) We do all sorts of power transfer now without wires.

 

2) Certainly there are concerns related to this. However, they can be easily overcome with proper design and procedures.

 

3) This won't be a problem. The Shuttle docks with the ISS while both are going ~ 17,500 MPH. It's not that tough to keep things in sync.

[wiffleball 4,796]

1) We do all sorts of power transfer now without wires.

[akaoni 0]

Here's what wiki has to say:

 

The earliest work in the area of wireless transmission via radio waves was performed by Heinrich Rudolf Hertz in 1888. A few years later Guglielmo Marconi worked with a modified form of Hertz's transmitter. Nikola Tesla also investigated radio transmission and reception.

 

Japanese researcher Hidetsugu Yagi also investigated wireless energy transmission using a directional array antenna that he designed. In February 1926, Yagi and Uda published their first paper on the tuned high gain directional array now known as the Yagi antenna. While it did not prove to be particularly useful for power transmission, this beam antenna has been widely adopted throughout the broadcasting and wireless telecommunications industries due to its excellent performance characteristics[15].

 

Power transmission via radio waves can be made more directional, allowing longer distance power beaming, with shorter wavelengths of electromagnetic radiation, typically in the microwave range. A rectenna may be used to convert the microwave energy back into electricity. Rectenna conversion efficiencies exceeding 95% have been realized. Power beaming using microwaves has been proposed for the transmission of energy from orbiting solar power satellites to Earth and the beaming of power to spacecraft leaving orbit has been considered [16],[17].

 

Power beaming by microwaves has the difficulty that for most space applications the required aperture sizes are very large. For example, the 1978 NASA Study of solar power satellites required a 1-km diameter transmitting antenna, and a 10 km diameter receiving rectenna, for a microwave beam at 2.45 GHz. These sizes can be somewhat decreased by using shorter wavelengths, although short wavelengths may have difficulties with atmospheric absorption and beam blockage by rain or water droplets. Because of the Thinned array curse, it is not possible to make a narrower beam by combining the beams of several smaller satellites.

 

High power

Wireless Power Transmission (using microwaves) is well proven. Experiments in the tens of kilowatts have been performed at Goldstone in California in 1975[18] [19][20] and more recently (1997) at Gand Bassin on Reunion Island[21].

 

Or you could use something called a "Laser"

 

In the case of light, power can be transmitted by converting electricity into a laser beam that is then fired at a solar cell receiver. This is generally known as "power beaming". Its drawbacks are:

 

Conversion to light, such as with a laser, is moderately inefficient (although quantum cascade lasers improve this)

Conversion back into electricity is moderately inefficient, with photovoltaic cells achieving 40%-50% efficiency[22]. (Note that conversion efficiency is rather higher with monochromatic light than with insolation of solar panels).

Atmospheric absorption causes losses.

As with microwave beaming, this method requires a direct line of sight with the target.

NASA has demonstrated flight of a lightweight model plane powered by a laser beam.

 

[wiffleball 4,796]

Wouldn't we catch the ozone layer on fire?

 

'Cause that would be bad...