Caltech and China Racing to Space Based Solar Power

18 thoughts on “Caltech and China Racing to Space Based Solar Power”

1. I think there is a slight mis statement, where "Before the
   beam leaves the security fence line (which is beyond the antenna
   itself), they would command the satellite to shut down or reduce power." seems to indicate that the beam is still in coherence, thus potentially strong, needing to be shut down. Now, it may need to be shut down for non safety reasons, but it should be clear that the beam *cannot* wander and be focused at all. No human safety intervention needed.

2. Makes me feel like an ant somehow.

   But sunlight is somewhat shorter wavelength than the power beams, so such focus is possible. Radio from a distance is a poor choice of weapon.

3. I have turned up the heat on the Earth to Earth power beaming to max. I follow Gandhi/Wheeler theories of information flow, so *if* you see the advantage of said beaming, essentially low voltage dc superconductors that go as far as needed, help!

4. Calculations show that a "simple" adaptive parabolic aluminium foil mirror with the diameter of 1 km placed on GSO can concentrate on the Earth a 10 cm sunlight beam having 100-150 MW power.

   Just to boost ground based solar tower electric plants, yeah…

5. Even when it is at full strength, it is 20% of sunlight.

6. Seems to me that Earth to Earth power beaming takes advantage of the Earth solar and wind, while also building the needed rectennae for Space Solar, the economic solution once we are in Space. Earth to Earth power beaming can go 1/3 around the Earth, thus from day to nite, the big variable.

7. You really think I thought it was a serious possibility that ". . . several such orbital facilities malfunctioned at the same time and hit the same population center?" In another country, even?

   The question may have been too subtle. Suppose someone in control of several of the space-based transmitters out to do as much damage as they possible can? Suppose they were able to design them with that thought in mind? Bear in mind that, if it is significantly destructive, they might not have to even use it, merely the threat to do so could be sufficient. Like with nukes.

8. Have you ever approached any silicon valley investors regarding this? You seem so passionate. Maybe you could help move the process along. What is keeping some billionaire from becoming a hero and helping mankind build a better future?

   Unless you think it should be built by the government. In which case it will never get done…

9. I used to work with the guys who came up with that failsafe. After startup, the phase reference transmitter, which is in the center of the ground antenna, is powered by the ground antenna. So if the beam wanders, the reference beam stops, and the satellite beam loses coherence.

   Note that this is a failsafe. If the beam wanders *at all* from being centered, the ground antenna output will go down, and the plant operators will notice. They would take corrective action to maintain output. Before the beam leaves the security fence line (which is beyond the antenna itself), they would command the satellite to shut down or reduce power.

   The beam intensity even at the beam center is lower than sunlight, so it can't be a death ray even if they tried. Not a good idea to stand unprotected in the beam center for extended times, but then neither is standing in a coal furnace when it is running. Plant workers would have reflective suits, like firemen use, if they need to work outside when the beam is on.

   What Snazter and many other commenters don't get is that an engineer's first professional duty is protecting lives. So we have thought about this stuff already.

10. > Commercial, gigawatt-level power generation would be realized by 2050.

    Meanwhile "Around 400GW of nameplate module manufacturing capacity and nearly 325GW of nameplate cell capacity could be online by the end of 2021". So the question is if there will be any market left to fill in 2050. I recognize that ground solar converts about 5:1 vs space solar, because lower capacity factor. But that still leaves a factor of 80 today vs what might be in 30 years.

    Fusion has the same problem. By the time it reaches significant capacity, the world may not need it.

    https://www.pv-tech.org/global-module-capacity-to-boom-in-2021-while-chinese-polysilicon-expansions-to-sidestep-xinjiang/

11. I read about space solar power & power beaming back a few decades ago. According to that, to get the beam to be tightly focused you need to have all the separate microwave generators in the transmitter in space in phase. Apparently it is fairly easy to arrange it so the keeping in phase is done by using a signal from the receiver antenna on earth. That way if the transmitter pointing goes wrong it goes out of phase & instead of a tight beam pointing at the wrong place, you get microwaves broadcast. A nuisance rather than a disaster.

12. The Chinese have an obvious interest in clean, efficient power; we all do.

    But it occurs to me to wonder, what would be the effect of a massive orbital microwave facility missing its capture array and hitting a nearby population center? Or one that is far off and in another country? Suppose several such orbital facilities malfunctioned at the same time and hit the same population center?

    Suppose instead the microwaves missed the Earth altogether and swept through an orbit used by many satellites?

    Maybe the answer is not much, at least not in the short term, I haven't researched it yet. But it's a question I hope other countries have considered.

13. Nah, ITER won't be generating anywhere close to that by 2050. Not scheduled for first plasma before 2025 (which will slip) and DT fusion by 2035 (will slip further).

    In ITER FAQ, any question about whether there will be future delays/schedule slips is answered with a description of how difficult what they're doing is – in essence answering "yes, of course there'll be delays and slips".

14. Interesting sidenotes here, they want to do a 20km height demo at 100KW at the new development facility they are restarting finishing recently, with the test in a few years. Which they suggested was to be a solar airship, which is similar to many HALE UAV concepts. Someone pointed out earlier PLA experiments with a "Tian heng" airship might fit the description of a solar forever flyer airship to be used for such a demo, as it would already be equipped with a lot of solar power, supposedly to power a surveillance radar (which isn't all that different from a microwave emitter).

    The gigawatt demo is a bit of pipe dream, in the sense that that it would be a full scale pilot plant SPS located in GEO with the 1km diameter transmitter. No way the chinese can affordably launch that on the current improved Long March 9 design. A fully reusable Starship/Super Heavy RLV TSTO copy would change the economics of that though, but Long March 9 as currently envisioned would have trouble evolving into a SS/SH clone as is.

15. Criswell would have "20 TWe BY 2050 & 1,000 TWe-y BY 2070" if started a little over ten years ago. Yes, GWs are a stupidly small plan.

16. Search Criswell LSP find searchanddiscovery link. See ppg 12-13 for Earth to Earth power beaming. Add in the excess solar and wind being collected on Earth systems, due to intermittency. Take advantage of the intermittency. Then, add in the Space Solar collectors. This simple plan will cause no further thermal electricity plants to be needed. It will provide the power to scrub CO2 from the air. Interested?

17. Gigawatt power by 2050?

    ITER might be here sooner.

    Just saying.

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