[ExI] StratoSolar article

Jeff Davis jrd1415 at gmail.com
Sun Sep 4 21:06:37 UTC 2011

On Fri, Sep 2, 2011 at 9:59 PM, Keith Henson <hkeithhenson at gmail.com> wrote:
> For those who care about such issues,
> http://www.theoildrum.com/node/8323
> Keith Henson

Thanks, Keith.  A question, if you please.

In the last few years, differing designs have emerged aimed at
harvesting solar power.  StratoSolar's design is yet another.  There
are updraft towers, downdraft towers, parabolic troughs and fields of
mirrors, and of course PV.  Others?

In July, Damien posted this:


(The downdraft tower is perhaps unfamiliar to you, so let me tell you
how that works.  In an updraft tower heated air rises because it is
lighter than the surrounding air.  In a downdraft tower the conditions
are reversed, cooler denser (ie heavier air) flows downward through
the tower.   Water mist is injected at the top of the tower, cooling
the air.)

Somewhere (I can't find it) in the follow-on discussion to your piece,
it was mentioned that the diameter of the light pipe must be 30-50
meters to avoid excessive losses due to internal reflection.  Okay.
Fine. Understood.  But I noticed something that got me to thinking.
And I wonder if, in the process of working on this project, you had
noticed it as well.

If the light pipe is narrower, and all the light is absorbed by the
"reflective" lining, then the lining heats up, no?  The lining, being
adjacent to it, heats the interior air, which then rises.
Concentrated light flows down, heated air flows up.  Voila, updraft
tower.  Of course, extensive analysis and redesign is needed, since
the forces are completely different, but there's the idea.  Did you
happen to notice?

I only read your Oil Drum piece yesterday, so my subconscious hasn't
had much chance to process this info yet, but one idea -- one variant
-- came to mind.  StratoSolar introduces the airborne solar collector,
which injects concentrated sunlight into a light pipe.  If we strap
this to the EnviroMission updraft tower, we can dispense with the
solar collection field surrounding the base of that tower, and convert
the "bare" tower into a combination high-end skyscraper slash solar
power facility. Then the EnviroMission becomes city friendly, and with
proper design perhaps VERY city friendly.  Cities are heat islands to
begin with, a plus that not only contributes to power generation, but
in summer, the air flow could help cool the city.  Tip of the

Crackpottery, or Ass Burgers generated genius, you be the judge.

PS Someone in Silly Con Valley really must open a small eatery and call it...

                         Ass Burgers. "We FOCUS... on the Burger!"

Best, Jeff Davis

 Aspiring Transhuman / Delusional Ape
     (Take your pick)
           Nicq MacDonald

More information about the extropy-chat mailing list