That might be the entire problem with the concept.  Energy companies are (must be) conservative and want to rely on proven energy generation.  Getting a utility to sign up for this venture and then to commit to using the output to deliver to the grid .... that will take some selling.  I skimmed the article and didn't see any input from anyone _in_ the energy industry.

Last year an idea was floated in article format that proposed using SPS to smooth out peak demands in the existing system - that might be a way to poke the camel's nose under the tent, so to speak.

Yes, I do.

From the utility executive's point of view, you're talking about an extention on business-as-usual.  A new reactor design is just that, but they've been _doing_ nuclear power for their entire lives, and they have an extensive knowledge base around the concept, infrastructure and so-on.  

Plus the guys who _do_ nuclear power will be wary of this - a Kw generated by solar is a Kw they don't make and that's money out of their budget.  This is 'strange' and new and my point, I think, stands.  You'll need to be a mighty good salesman to pitch it to them.

Why don't we just do it?

If the energy companies are so conservative, then they don't deserve the big risky gains.  The numbers you guys are throwing around will be in the sort of range we will have when we get a space elevator, and the most significant part of this operation will be in stuff that a private space elevator company will have experience in, not the on the ground distribution stuff that they are skilled in.  

So how exactly are they proposing doing this?  PV cells with beamed power to Arizona or wherever?  PV is like 3% efficient or something like that right?  And worth more than its weight in gold if you get the best stuff.  Why not just use micron thick mirrors that are hundreds of miles wide and concentrate them to beam back the power?  Also, how do you deal with shadows?  Whoever's hemisphere you build this over isn't going to appreciate having a big shadow in the sky and occasional eclipses.

Another interesting feature of this system is that the PV arrays on the ground will work much better given some cooling, in fact probably required.  Turns out that the cooling system "should" (i still have to do the details) be an excellent way to desalinate water by evaporation.  Can anyone think of a place that has access to salt water and need fresh water?

The purpose of the alternative orbit is to gain added geosynchronous slots.  Being able to design the orbit to avoid shadow is a minor, and agreed, perhaps not even significant, advantage.  Being shadowed occasionally by latitude 15 rather than latitude 0 IS a questionable advantage.


I believe you'll find that statement not to be true for two reasons.  First, the only safe place to attach a significant single additional mass to the mirror without unbalancing it's rotation is at the top mass.  Problem is, from this position the earth is always behind the mirror, which won't allow passage of most electromagnetic waves.  Second, in the volume envisioned (e.g. a fast install of 60 mirrors, then continual additions sufficient to intercept plans such as this from the homepage of Arch Coal of St. Louis, "Over the next 20 years, electricity demand in the United States will increase by 45%, according to estimates by the US Department of Energy."  They are obviously hoping to make it all coal.  If instead it were all mirror-suplemented PV, even the auxiliary orbit slots will run out unless the units are seriously scaled up.  Then there's the rest of the world.


If you look at today 2:12AM post, again:

Also, this is a LOT simpler, cheaper and less risky than the SPS satellite system. Note from the article,

"Another interesting comparison to this proposal is the SunTower5 (SSP) design currently being promoted and supported by NASA’s Glen Research Centre and presented by James Powell, John Paniaguia, and George Maise to the 51st International Astronautical Congress at Rio de Janeiro, Brazil in Oct. 2000. They propose a 15,700 ton satellite in GEO orbit comprised of 1,200 MWe photovoltaic cells and 1,500 tons of superconducting distribution, along with a 1,200 MW microwave transmitter and a 90% efficient microwave receiver earth station connected to submit power to an HVAC grid. In their estimates, they propose that this entire assembly might be set up for $3,000 / net kw, but even presuming a non-profit space elevator delivering loads to GEO at $100/kg, that budget still leaves them over $2 billion short just to pay for $2,800 / kw photovoltaic manufacturing, and with no allowance then for the 1,500 tons of superconductor with cryogenic refrigeration, or the microwave equipment, control, or earth station systems."

TSSOM article proposes paying SE $1,000/kg to GEO."

Or see http://www.newworlds.com/reports/PUR-14.PDF If that doesn't scare you about irrational thought .....

Ok Bob.  I gotta eat some crow on this.  I've revised the website to eliminate any discussion of shadow, agreed it's not even worth mentioning.  I also added a revised option to the design which moves the "stabilizing weight" out in front of the mirror so a communications package attached to it could still function properly if it can survive the added reflected light. (about 95% additional).  I still think that, even with this strategy allowing one mirror to occupy each slot in the Clark orbit, if it's exploited properly more satellites than slots available, but perhaps delayed some.  Also has the added disadvantage that in this configuration, the mass of the stabilizing weight needs to be about as much larger than the total weight of the system as the reverse configuration's one is smaller, eg. might change from 70 tons to 150 tons.  That added mass to GEO might entirely negate any benefits.

Still doesn't change the need for a cheap (eg <$1000/kg to GEO) heavy lifter.

I've been trying to work out how you think you're going to distort the mirror to focus sunlight across 36,000 km into a spot on Earth approximately the same size as the mirror.  I don't think it can be done, and beyond that I'm not sure you realize that a flat mirror won't do the job.

The Sun is not a point source; it's about 0.5° across as seen from the Earth (or GEO).  An observer on the Earth will only be able to "see" a tiny fraction of the Sun's area reflected in the mirror, and will therefore receive only that tiny fraction of the energy from the Sun reflected from the mirror. To reflect a "full sun" to the Earth's surface, your mirror would have to have the same apparent diameter as the Sun (and, in a huge coincidence, the Moon).  Since it's about 1/10th as far away as the Moon, your mirror would have to be 1/10th the diameter of the Moon to do what you want it to do.

If you are planning to focus by distorting the mirror, HOW?