Not signed in (Sign In)
    •  
      CommentAuthorrickiep00h
    • CommentTimeMay 30th 2008
     (2422.1)
    India contemplates space-based solar power.

    Couldn't we just turn Mercury into a solar harvest area? It worked in Transmet...
  1.  (2422.2)
    How I wish we could.

    This article and the reports it quotes from is incredibly encouraging but, unfortunately, I doubt politicians will listen. That isn't me being cynical. When the costs are huge and the tech's experimental, history's proven that most wont take the risk.

    Considering Obama's technocratic ways, is there any chance he might listen as - hopefully for all my American friends here & elsewhere and for the rest of us - the next president of the US? Does he have an email to send these things to? Wouldn't that be awesome, direct email contact with your next president - maybe a US citizen should email him...anyway, I digress.

    Wicked find, rickie.
    • CommentAuthorchenryhen
    • CommentTimeMay 30th 2008
     (2422.3)
    I was talking to a friend about this, and he asked (and I didn't know the answer) "wouldn't this create one hell of a no-fly zone?"

    Would that be a serious problem? Could it cause big problems if there's some alignment error?
    • CommentAuthorKosmopolit
    • CommentTimeMay 30th 2008
     (2422.4)
    Most designs involve the satellite sitting in geosynchronous orbit 23,000 miles above the Earth.

    The limits of current antenna technology mean that by the time the power beam has crossed that distance you need a receptor bigger than a football field and the average field strength is probably lower than from your mobile phone.
  2.  (2422.5)
    I'm seeing the only advantage of space-based arrays being the absence of cloud cover. What am I missing here?
    • CommentAuthornleavitt
    • CommentTimeMay 30th 2008
     (2422.6)
    Yeah, I'm pretty sure it would make more sense, and cost about the same, to put solar panels and windmills on every building on earth. I can see it now: month-long blackouts caused by meteors.
    • CommentAuthordkostis
    • CommentTimeMay 30th 2008 edited
     (2422.7)
    @ Val A Lindsay II
    "I'm seeing the only advantage of space-based arrays being the absence of cloud cover. What am I missing here? "

    Cloud cover absorbs about 1/3 of the solar energy that enters our atmosphere (I can't recall if that is just the visible spectrum of light or all the energy), but the atmoshere reflects about 30% of all solar energy before it enters.

    There are also significant advantages in surface area and weight afforded by building arrays in zero-gravity.
  3.  (2422.8)
    We need to be more effient in actually collecting the energy we're hit with in order for such a thing to work. And if we figure that out, we might not need to go to such extremes to harvest said energy.
  4.  (2422.9)
    Don't get me wrong. This may be one of those things that gets us into space. I'm just wondering about the cost of this versus how much we get back out of it. Is it logical to build this in space when we have vast areas everywhere on the globe that see little cloud cover. The Southwest U.S. is a huge area that sees a tremendous amount of solar energy going straight into the Earth. I'd say building in places like that first would make more sense...
    • CommentAuthordkostis
    • CommentTimeMay 30th 2008 edited
     (2422.10)
    I can't agree that building on the relatively little undeveloped land we have remaining is worth the short term savings. In the long run building in space has consistently been cost effective (that means profitable).
    Orbital collectors also have other advantages including effectively unlimited expansion, around the clock exposure to solar energy and a relatively stable enviroment. The same can not be said for ground based arrays.
  5.  (2422.11)
    Undeveloped land? I don't know about that. We've got hundreds of square miles of land ready for solar farms in Nevada, Arizona and here in New Mexico alone.

    How big of an array are you thinking can be in orbit?
    •  
      CommentAuthorAdam
    • CommentTimeMay 30th 2008
     (2422.12)
    I'm just wondering about the cost of this versus how much we get back out of it.


    See, this is why we need to develop and pony up the cash for a workable Space Elevator. Once such a system is in place, collection and storage of resources (such as stored solar energy) could take place in space, and then just shimmied down while something else is on its way up, for next to no cost.
  6.  (2422.13)
    I just look forward to the day when I can affordably coat my roof entirely in solar panneling. You might think it's to save energy and be self sufficient, but really I think it'll help stop the fucker from leaking.
    • CommentAuthorVerissimus
    • CommentTimeMay 30th 2008
     (2422.14)
    Why don't we just give every person currently living in Chad $ 100,000, buy them a nice house somewhere else, and cover the entire desert with solar panels?
    •  
      CommentAuthorLinsterg
    • CommentTimeMay 30th 2008
     (2422.15)
    Why don't we just give every person currently living in Chad $ 100,000, buy them a nice house somewhere else, and cover the entire desert with solar panels?


    Do you think they would hold out for that much?
    • CommentAuthorKosmopolit
    • CommentTimeMay 30th 2008
     (2422.16)
    "I'm seeing the only advantage of space-based arrays being the absence of cloud cover. What am I missing here?"

    The atmosphere absorbs a lot of the solar energy so you get around that - basically microwaves are transmitted through air with much lower losses than light or IR radiation.

    As well as the lack of cloud cover a powersat in geosynchronous orbit is in day light for 99% of the time - plus there's no seasonal variations to worry about.
    • CommentAuthorKosmopolit
    • CommentTimeMay 30th 2008
     (2422.17)
    Powersats in geosynchronous orbit have to be huge because they're transmitting energy across 23,000 miles.

    There are lot of pros and cons but I think to begin with what we'll see is powersats in low earth orbit (like 100 miles up).

    The pros -
    much lower transmission losses,
    lower launch costs
    the system is scaler, you can start with a small sat and add more if it works. With geosynchronous you're pretty much committed to a trillion dollar investment before you see watt one.

    The cons

    - you'd spend much of the time in Earth's shadow losing one of the big advantages of going into space in the first place;

    - the risk of collision from space junk woudl be much higher;

    - you'd need multiple receivers on the ground although each one would be a lot smaller than for the geosynchronous version.
  7.  (2422.18)
    I can appreciate the advantages and all, but I can't help but see these problems...

    1) The cost of getting said panels into space

    2) Even if being in open space, I'm not sure with even 30% extra efficiency from having a panel in space outweighs the cost of a 30% more efficient solar cell.

    3) The damage/destruction potential of open space combined with the cost of repair adds up heavily at the moment.

    Again, don't get me wrong. If we did a space array, I wouldn't be against it. Hell, it's quite unlikely but it could be the political vehicle that adds to the foothold of getting into space.

    All this said, if Germany, one of the cloudiest places on Earth is putting up solar fields, we sure as heck should be doing it here, even if only to power the states in the southwest.
    •  
      CommentAuthorCyman
    • CommentTimeMay 31st 2008
     (2422.19)
    I think I agree mostly with Val.
    We have 'space' (heh) on Earth to do it, I don't see why we'd bother building solar panels on a space elevator before we have exhausted the solar panel tech here first.
    And how efficient would it really be to transport all that energy back down to us from thousands of feet in orbit? Especially considering 60% of that energy is just coming to Earth anyway...
    •  
      CommentAuthorGinger Ian
    • CommentTimeApr 14th 2009 edited
     (2422.20)