Clark Lindsey's always up-to-date Space Transport News blog has a link to The Space Show's podcast with Pete Worden and reports that the NASA Ames Resaerch center director has a dim (geddit?) view of Space Based Solar Power (SBSP)
And Hyperbola could not agree more with his analysis. The problem with solar power is not whether you have what is basically a magnifying glass in orbit but how good your solar arrays are in orbit, or on Earth, at converting sunlight into electricity and how much it costs to manufacture and install or launch that array. As for ideas about beaming power down to Earth in the microwave bandwidth, it won't be much good with clouds in the way as moisture is a good absorber of microwaves
Seeing the Obama administration's website festooned with papers on SBSP has not been encouraging and yesterday Obama spoke of solar power in glowing (excuse the pun) terms while discussing with the ISS crew that station's use of solar power
At London's Royal Aeronautical Society last year Elon Musk was asked about SBSP. He said that as the owner of a launcher company and as an investor in solar power he should be a champion of it but he actually thought it was a dead end. So there you go, feel free to flame away SBSP enthusiasts
And Hyperbola could not agree more with his analysis. The problem with solar power is not whether you have what is basically a magnifying glass in orbit but how good your solar arrays are in orbit, or on Earth, at converting sunlight into electricity and how much it costs to manufacture and install or launch that array. As for ideas about beaming power down to Earth in the microwave bandwidth, it won't be much good with clouds in the way as moisture is a good absorber of microwaves
Seeing the Obama administration's website festooned with papers on SBSP has not been encouraging and yesterday Obama spoke of solar power in glowing (excuse the pun) terms while discussing with the ISS crew that station's use of solar power
At London's Royal Aeronautical Society last year Elon Musk was asked about SBSP. He said that as the owner of a launcher company and as an investor in solar power he should be a champion of it but he actually thought it was a dead end. So there you go, feel free to flame away SBSP enthusiasts
on March 25, 2009 1:32 PM | Reply
As for ideas about beaming power down to Earth in the microwave bandwidth, it won't be much good with clouds in the way as moisture is a good absorber of microwaves.
While there a lot of problems with SPS, this is simply untrue. The frequency planned for the reference concepts (2.45 GHz) doesn't interact with water (it's not resonant with the H2O molecule). That is why it was chosen.
on March 25, 2009 3:43 PM | Reply
It is not untrue that microwaves and water interact, microwave ovens work on the principle of heating the water contained by a food.
on March 25, 2009 4:22 PM | Reply
Yes, the most commonly used radio wave frequency used in microwave ovens is approx. 2.5 GHz. Radio waves in this frequency range are absorbed by water, fats and sugars.
on March 25, 2009 4:33 PM | Reply
It is not untrue that microwaves and water interact, microwave ovens work on the principle of heating the water contained by a food.
I didn't say that microwaves and water don't interact. I said that the specific frequency chosen for SPS (there is a wide frequency range that is called "microwave") minimized that interaction. While it's not authoritative, Wikipedia seems to get it right here.
"To minimize the sizes of the antennas used, the wavelength should be small (and frequency correspondingly high) since antenna efficiency increases as antenna size increases relative to the wavelength used. More precisely, both for the transmitting and receiving antennas, the angular beam width is inversely proportional to the aperture of the antenna, measured in units of the transmission wavelength. The highest frequencies that can be used are limited by atmospheric absorption (chiefly water vapor and CO2) at higher microwave frequencies."
It is chosen to be long enough wavelength to minimize atmospheric losses (even through clouds) while being short enough to keep rectenna sizes reasonable. This was all worked out over three decades ago. As I said, there are a lot of problems with SBSP, but this is not one of them. The people who came up with this weren't stupid.
on March 25, 2009 9:29 PM | Reply
The amount of money we're taxed on to fund SUV's & mcmansions makes a SBSP look like a deal.
on March 26, 2009 1:08 AM | Reply
I can't believe the premise of this post is praise for Pete Worden. Have you met this guy? He [edited for politeness] wouldn't know a solar array if it was right in front of him.
on March 26, 2009 2:11 PM | Reply
.
the SSP is just a CRAZY and VERY EXPENSIVE "idea" as explained in this article:
http://www.ghostnasa.com/posts/038sspdebunked.html
.
on March 27, 2009 8:06 PM | Reply
SBSP _could_ deliver base load, while terrestrial could not. Hence, its not just a mangnifying glass.
Your arguments are therefore null and void.
on March 29, 2009 9:23 AM | Reply
1. Rand is correct. At the relatively low frequencies being considered, water absorption is not a problem at all. Once you get up above 30 GHz or so, then weather matters.
2. I have seen the exact situation described by A. Non and I can say without hesitation that Dr. Worden has an excellent knowledge of solar array technology.