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China wants to put a solar farm in space by 2025

engadget.com

11–20 of 62 posts

Re: China wants to put a solar farm in space by 2025

#11
They intend to beam the energy to earth through a laser. I wonder if building a space-mirror and focussing a beam of sunlight would be a much easier and scalable solution.

Though I guess you would need multiple base stations to beam it somewhere where there's no clouds?

Re: China wants to put a solar farm in space by 2025

#12
I was pushing this a decade ago.

If you have "fusion in a bottle" and don't want to share, this is a decent way to make it harder to steal/damage/use-for-terrorism.

Also, giant beam transmission facilities and giant beam weapons aren't so different from each other. There are going to be detectable critical differences, but with some modifications one can be made into the other.

Radiation damage is going to be a challenge but satellites do with solar for a long time. Onboard robots?

Re: China wants to put a solar farm in space by 2025

#13
post #3

How do they plan to beam energy back to Earth?

Do they need to? I wonder how feasible it would be to put large computational centers in space and have space solar farms powering these computational centers. So if we want to test complex or long-running programs/models/algos, we can just beam it to the computational centers orbiting earth and wait for the results when it's finished.

How do you cool them in space?

Re: China wants to put a solar farm in space by 2025

#14
post #2

Finally, somebody decided to make solar collectors in space. Been waiting for it since it was discussed in Isaac Arthur. I bet spaceX might do something similar in the future. When they are not as encumbered with star link and the BFR.

1) It is not much more efficient due to transmission losses. (Compared to high voltage DC.) 2) The costs, on top of super expensive solar panels, make this totally pointless economically. Solar panels are hard enough to maintain on Earth. 3) It's a multi gigawatt level microwave gun in space. Want to blast some lightning onto someone? Sure, now you can. Or fry it.

Well... I mean china is pretty capable of breaking the kneecaps right now of whomever they want in their territory. I doubt they will use it as ion cannon.

Re: China wants to put a solar farm in space by 2025

#15
post #11

They intend to beam the energy to earth through a laser. I wonder if building a space-mirror and focussing a beam of sunlight would be a much easier and scalable solution. Though I guess you would need multiple base stations to beam it somewhere where there's no clouds?

Using a wavelength transformation to send this through the non-absorption windows means more energy hits the ground and you aren't hacking terrestrial albedo in a bad way. That global warming is about absorption of sunlight, so putting a lot more sunlight on the same absorption percent means more heat retained. It doesn't do any good to cut gwp materials in the air, then increase sunlight hitting the atmosphere in a way that makes heat retention higher.

Re: China wants to put a solar farm in space by 2025

#17
post #2

Finally, somebody decided to make solar collectors in space. Been waiting for it since it was discussed in Isaac Arthur. I bet spaceX might do something similar in the future. When they are not as encumbered with star link and the BFR.

1) It is not much more efficient due to transmission losses. (Compared to high voltage DC.) 2) The costs, on top of super expensive solar panels, make this totally pointless economically. Solar panels are hard enough to maintain on Earth. 3) It's a multi gigawatt level microwave gun in space. Want to blast some lightning onto someone? Sure, now you can. Or fry it.

The costs just to put the materials up there makes me wonder the long term viability of just trying to source it from the moon. By the time you are willing to spend the billions required it cannot be much more of step and provides other uses.

still I have to agree, how do you even maintain something like this. it would probably lead to a full time presence in space unless robotics become just that good. I just don't see the ROI except may be for national pride.

Re: China wants to put a solar farm in space by 2025

#18
post #11

They intend to beam the energy to earth through a laser. I wonder if building a space-mirror and focussing a beam of sunlight would be a much easier and scalable solution. Though I guess you would need multiple base stations to beam it somewhere where there's no clouds?

Actually, maser - microwave laser.

The mirror is a fine grid which makes it much lighter and more resilient, and it is much easier to convert into electricity than light.

Re: China wants to put a solar farm in space by 2025

#19

Earlier quoted context omitted.

Do they need to? I wonder how feasible it would be to put large computational centers in space and have space solar farms powering these computational centers. So if we want to test complex or long-running programs/models/algos, we can just beam it to the computational centers orbiting earth and wait for the results when it's finished.

How do you cool them in space?

Do you need to? Without enough gas in space, how likely is it for something even as powerful as a data center to overheat?

Re: China wants to put a solar farm in space by 2025

#20
post #2

Finally, somebody decided to make solar collectors in space. Been waiting for it since it was discussed in Isaac Arthur. I bet spaceX might do something similar in the future. When they are not as encumbered with star link and the BFR.

1) It is not much more efficient due to transmission losses. (Compared to high voltage DC.) 2) The costs, on top of super expensive solar panels, make this totally pointless economically. Solar panels are hard enough to maintain on Earth. 3) It's a multi gigawatt level microwave gun in space. Want to blast some lightning onto someone? Sure, now you can. Or fry it.

Economics changes all the time. The launch costs are supposed to come down. The cost of getting land for the cells and transmission lines goes up all the time, which makes orbit actually more attractive. The weight/cost/efficiency of panels gets better all the time.

And the efficiency! 10X the solar flux outside the atmosphere! And in the right orbit, 2X again because of course night quits being an issue. So a potential 20X better utility per square.

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