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0 pointsmikepurvis3y ago0 comments

That's pretty sobering, since you can produce/capture quite a lot of energy with 100km^2 of clear, flat ground that has a view of the sky.

Not least by just putting normal solar panels on it and jettisoning the whole space part.

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3 comments · 1 top-level

DennisP3y ago· 2 in thread

Yes but with SPS, that 100km^2 is mostly just antenna wire, and you don't need any sort of energy storage.

ben_w3y ago

At 6cm spacing, a 10km by 10km ground array with 1mm^2 cross section wires has total 1667 m^3 volume; this is as much conductor as you would get in the equivalent of a 1111 km long 1 GW HVDC cable: https://www.wolframalpha.com/input?i=10km*10km%2F6cm*1mm%5E2...

It's not exactly the same thing, of course, but it means 40 such ground stations would use as much metal as a 1 GW line looping all the way around the planet and back to itself, and a global grid is another way to obviate storage.

That's 1 GW with standard existing cables; I assume if you actually want to go that far one can improve the design as the optimisation goals are different. Parallel cables lower resistance.

I'm also not sure how much maximum current would scale in such cases.

mikepurvisOP3y ago

I think part of the theory with space based solar is to put many small collectors all over the place and avoid some of the need for all that heavy duty long distance transmission infrastructure.

But any benefit there also goes out the window if the SBS reciever is too large or dangerous or scary or ugly to have located all over the place.

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