The following warnings occurred:
Warning [2] Undefined variable $awaitingusers - Line: 33 - File: global.php(779) : eval()'d code PHP 8.1.27 (Linux)
File Line Function
/global.php(779) : eval()'d code 33 errorHandler->error
/global.php 779 eval
/showthread.php 24 require_once
Warning [2] Undefined array key "style" - Line: 837 - File: global.php PHP 8.1.27 (Linux)
File Line Function
/global.php 837 errorHandler->error
/showthread.php 24 require_once
Warning [2] Undefined property: MyLanguage::$lang_select_default - Line: 4950 - File: inc/functions.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions.php 4950 errorHandler->error
/global.php 837 build_theme_select
/showthread.php 24 require_once
Warning [2] Undefined variable $visibleonly - Line: 412 - File: showthread.php PHP 8.1.27 (Linux)
File Line Function
/showthread.php 412 errorHandler->error
Warning [2] Undefined array key 1 - Line: 1394 - File: inc/functions.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions.php 1394 errorHandler->error
/inc/functions.php 1359 fetch_forum_permissions
/inc/functions.php 2862 forum_permissions
/showthread.php 616 build_forum_jump
Warning [2] Undefined array key 1 - Line: 1394 - File: inc/functions.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions.php 1394 errorHandler->error
/inc/functions.php 1359 fetch_forum_permissions
/inc/functions.php 2862 forum_permissions
/showthread.php 616 build_forum_jump
Warning [2] Undefined array key "mybb" - Line: 1907 - File: inc/functions.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions.php 1907 errorHandler->error
/inc/functions_indicators.php 41 my_set_array_cookie
/showthread.php 624 mark_thread_read
Warning [2] Undefined property: MyLanguage::$ratings_update_error - Line: 5 - File: showthread.php(727) : eval()'d code PHP 8.1.27 (Linux)
File Line Function
/showthread.php(727) : eval()'d code 5 errorHandler->error
/showthread.php 727 eval
Warning [2] Undefined array key "additionalgroups" - Line: 6846 - File: inc/functions.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions.php 6846 errorHandler->error
/inc/functions_user.php 734 is_member
/inc/functions_post.php 398 purgespammer_show
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "profilefield" - Line: 6 - File: inc/functions_post.php(466) : eval()'d code PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php(466) : eval()'d code 6 errorHandler->error
/inc/functions_post.php 466 eval
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "canonlyreplyownthreads" - Line: 641 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 641 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showimages" - Line: 699 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 699 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showvideos" - Line: 704 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 704 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "additionalgroups" - Line: 6846 - File: inc/functions.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions.php 6846 errorHandler->error
/inc/functions_user.php 734 is_member
/inc/functions_post.php 398 purgespammer_show
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "profilefield" - Line: 6 - File: inc/functions_post.php(466) : eval()'d code PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php(466) : eval()'d code 6 errorHandler->error
/inc/functions_post.php 466 eval
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "canonlyreplyownthreads" - Line: 641 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 641 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showimages" - Line: 699 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 699 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showvideos" - Line: 704 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 704 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showimages" - Line: 742 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 742 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "additionalgroups" - Line: 6846 - File: inc/functions.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions.php 6846 errorHandler->error
/inc/functions_user.php 734 is_member
/inc/functions_post.php 398 purgespammer_show
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "profilefield" - Line: 6 - File: inc/functions_post.php(466) : eval()'d code PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php(466) : eval()'d code 6 errorHandler->error
/inc/functions_post.php 466 eval
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "canonlyreplyownthreads" - Line: 641 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 641 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showimages" - Line: 699 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 699 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showvideos" - Line: 704 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 704 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "additionalgroups" - Line: 6846 - File: inc/functions.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions.php 6846 errorHandler->error
/inc/functions_user.php 734 is_member
/inc/functions_post.php 398 purgespammer_show
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "profilefield" - Line: 6 - File: inc/functions_post.php(466) : eval()'d code PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php(466) : eval()'d code 6 errorHandler->error
/inc/functions_post.php 466 eval
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "canonlyreplyownthreads" - Line: 641 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 641 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showimages" - Line: 699 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 699 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showvideos" - Line: 704 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 704 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "additionalgroups" - Line: 6846 - File: inc/functions.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions.php 6846 errorHandler->error
/inc/functions_user.php 734 is_member
/inc/functions_post.php 398 purgespammer_show
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "profilefield" - Line: 6 - File: inc/functions_post.php(466) : eval()'d code PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php(466) : eval()'d code 6 errorHandler->error
/inc/functions_post.php 466 eval
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "canonlyreplyownthreads" - Line: 641 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 641 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showimages" - Line: 699 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 699 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showvideos" - Line: 704 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 704 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "showimages" - Line: 742 - File: inc/functions_post.php PHP 8.1.27 (Linux)
File Line Function
/inc/functions_post.php 742 errorHandler->error
/showthread.php 1057 build_postbit
Warning [2] Undefined array key "invisible" - Line: 1491 - File: showthread.php PHP 8.1.27 (Linux)
File Line Function
/showthread.php 1491 errorHandler->error
Warning [2] Undefined variable $threadnotesbox - Line: 30 - File: showthread.php(1518) : eval()'d code PHP 8.1.27 (Linux)
File Line Function
/showthread.php(1518) : eval()'d code 30 errorHandler->error
/showthread.php 1518 eval




Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Space Based Solar Power
#1
A new article of mine about Space Based Solar Power:

http://blog.the-brights.net/2016/12/05/space-based-solar-power-the-key-to-a-bright-future/#sthash.GdbIzHcQ.dpbs

Thanks,
Adam
Reply
#2
Great article!

I also went and read Maury's article, since he scoffed at your post.  But I don't think your post is scoff-worthy, and I think Maury overstates his conclusions.  He's comparing space solar to pretty much the best possible terrestrial solar — Nevada, and finding that solar cells in Nevada deliver more power over their lifetime by about a factor of 2.

But (1) a factor of 2 isn't always a deal-killer for a system that has other advantages, such as continuous, reliably supply; and (2) this factor of 2 might easily be made up for (or surpassed) by newer solar cell technologies that don't degrade so quickly from radiation damage, as suggested by the thin-film solar cell physicist in his comments.  So, despite Maury's scorn, SBSP is still worth considering.

A couple of thoughts on your piece...


Quote:Practical experiments related to SBSP have taken place, for example in Japan.  This involves the beamed transmission of energy over a distance of over fifty metres.


We've done a lot better than that; in 2008 power was beamed over 92 miles from island to island in Hawaii (reference).


Quote:If SBSP is to move forward, experiments in space are needed to prove the technology involved. An example of this could be a power satellite, somewhat smaller than the eventual structure at only 50 metres in diameter, being placed in geosynchronous orbit and beaming down power to a collecting station on the surface below.

Is that even possible?  My understanding was that antenna size was pretty much dictated by the distance over which you need to transmit (and the spot size you're willing to accept at the receiving end).  I thought this pretty much required km-scale antennas in GEO.

Perhaps a good way to do a smaller-scale demonstration might be a LEO powersat.  It's constantly moving over the surface of the Earth, of course, but you could beam power for a few minutes at a time, making an effective demonstration.

One other idea I've seen (and which we've incorporated into High Frontier) is the use of beamed power in space.  So you have your big powersat in some sunny orbit, with lots of solar panels and the infrastructure to maintain them; and this beams power to space stations and habitats that need it, and want to avoid that extra bulk.

Joe Strout
Lead Developer, High Frontier

Reply
#3
I agree SBSP would be an optimal supply for many space stations and industries. Solar power articles on some of the tech pages I read material developments are leading to solar panels at about $1 per sq ft and efficiencies of 35-50%. The efficiencies are achieved by multiple color layers each making power from it's part of the spectrum. Durability of cheap solar panels is heading to 20-50 year range. To my mind space to ground solar will not be needed.
Reply
#4
(12-07-2016, 12:19 PM)JoeStrout Wrote:
Quote:If SBSP is to move forward, experiments in space are needed to prove the technology involved. An example of this could be a power satellite, somewhat smaller than the eventual structure at only 50 metres in diameter, being placed in geosynchronous orbit and beaming down power to a collecting station on the surface below.

Is that even possible?  My understanding was that antenna size was pretty much dictated by the distance over which you need to transmit (and the spot size you're willing to accept at the receiving end).  I thought this pretty much required km-scale antennas in GEO.
This is based on the prototype Space Based Solar Power satellite described in this paper: http://enu.kz/repository/2009/AIAA-2009-4897.pdf
The description of the satellite is set out on pages 10 and 11.  I'm perfectly happy to be correct about this if appropriate!
Reply
#5
I guess you're right! A small transmitter like that generates a big spot on the ground — 7 km diameter in this case. But they're proposing to ignore most of that and receive just a portion with a 150 m rectenna for demonstration purposes. Makes sense to me!

Joe Strout
Lead Developer, High Frontier

Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)