Next Big Future: Liquid Flouride Thorium Reactor and Space Based Solar
GoatGuy
· 5 months ago
Just gotta love that powersat doohickey. My past opinion bears repeating: the fundamental set of premises that are the inspiration for space based power: ... 24 hr/day operation, ... little-to-no maintenance ... safe/clean/environmentally benign ... are all true, but at the same time overblown.
24hr/day operation - is provided, presently, very adequately, by all hydroelectric, nuclear and upcoming wind-based systems. There is fluctuation, to be sure, but they're all also balanced in real-time quite well (especially hydroelectric). The BASE is covered.
The cost of lofting stuff into space - of the scale imaged (never having been done, and moreover, larger by 3 orders-of-magnitude than anything yet done) ... is WAY more per kilogram than shooting communications and spy satellites into orbit. Without a doubt, people will have to assemble the monstrosities in mid-earth orbit (~2500 mi) 'cuz LEO would offer too much atmospheric friction, forces and orbital decay. Then, lofting it to 22,500 miles ... very very carefully ... would take a huge additional amount of propulsion. I'm not saying it can't be done! I'm saying, whatever the present abstracted orbital insertion cost per kg, I easily can see it over-running to the tune of 200% or 300%.
THEN, the straight economics kicks in: how many additional desert-region based solar cell arrays could have been purchased for the lofting-and-insertion price of the power-sat system (and the recipient microwave field?)
These are reasonable (if because of formatting, cryptic) notes: The first column is ground based. The second column of numbers if space based. I pulled the numbers out of my nether regions - but trying to be "reasonable". The EST on line (14) shows $323 per installed kilowatt-hour for ground based, and $600 per kilowatt hour for space based.
Except for the excitement of doing a huge space-based power system (and it is exciting), I think it makes much more sense to install 3x as many cells on the ground, and save all the exciting space work for something delivering a lot higher value and less risky.
You guys didn't read the post, they are delivering very small satellites to LEO, there is no need of "assembling" or "insertion" to high orbit, the micro satellites will propel themselves to high orbit.
All Comments
24hr/day operation - is provided, presently, very adequately, by all hydroelectric, nuclear and upcoming wind-based systems. There is fluctuation, to be sure, but they're all also balanced in real-time quite well (especially hydroelectric). The BASE is covered.
The cost of lofting stuff into space - of the scale imaged (never having been done, and moreover, larger by 3 orders-of-magnitude than anything yet done) ... is WAY more per kilogram than shooting communications and spy satellites into orbit. Without a doubt, people will have to assemble the monstrosities in mid-earth orbit (~2500 mi) 'cuz LEO would offer too much atmospheric friction, forces and orbital decay. Then, lofting it to 22,500 miles ... very very carefully ... would take a huge additional amount of propulsion. I'm not saying it can't be done! I'm saying, whatever the present abstracted orbital insertion cost per kg, I easily can see it over-running to the tune of 200% or 300%.
THEN, the straight economics kicks in: how many additional desert-region based solar cell arrays could have been purchased for the lofting-and-insertion price of the power-sat system (and the recipient microwave field?)
These are reasonable (if because of formatting, cryptic) notes:
The first column is ground based.
The second column of numbers if space based.
I pulled the numbers out of my nether regions - but trying to be "reasonable".
The EST on line (14) shows $323 per installed kilowatt-hour for ground based, and $600 per kilowatt hour for space based.
Except for the excitement of doing a huge space-based power system (and it is exciting), I think it makes much more sense to install 3x as many cells on the ground, and save all the exciting space work for something delivering a lot higher value and less risky.
TABLE:
3 Peak insolation 1000 1360 watt/sq meter
4 Mean insolation 333 1360 watt/sq meter
5 Cell effic 22% 27%
6 Cell cost/sq meter $150 $375
7 Vehicle (frame) cost/sq meter $100 $200
8 Cost/peak kilowatt $1,136 $1,566
9 Cost/mean kilowatt $3,409 $1,566
10 kWh/sq.m/day 1.76 8.81
11 Conversion efficiency 90% 65%
12 kWh/sq.m/day (usable) 1.58 5.72
13 Conversion stn cost(per kw) $100 $150
14 Installed cost per kWh: $323 $600
15 : Cells $95 $65
16 : Vehicle (frame) $63 $35
17 : Conversion $100 $150
18 : Deployment (labor+fab) $50 $200
19 : Transportation $5 $100
20 : Insurance $10 $50
This was discussed (along with a lot of side issues) in a recent issue of The Oil Drum.
http://www.theoildrum.com/node/5485