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Ultimately the problem with these plans is that solar panels are cheap, but launching them into space is not. There is no point in the near future where launch

Ultimately the problem with these plans is that solar panels are cheap, but launching them into space is not. There is no point in the near future where launch costs become so cheap that it doesn't make sense to do this instead just building ten times as many panels for the same cost and installing them around the world. The math may change if we ever deploy a space elevator or do asteroid capture and orbital mining/manufacturing, but those are all in the distant future.

spiralk 2y ago
If SpaceX succeeds with Starship, projected launch costs to LEO could be as little as $10/kg. Even off by an order of magnitude, $100s/kg might be enough to make it viable. There are plenty of population centers where land is scarce or there are bureaucratic hurdles due to stubborn land owners.
- adrianN 2y ago
  A solar panel weighs like 10kg and costs about $100. Then you also need equipment to produce the microwaves, fuel and an engine to keep the thing in place...
  - spiralk 2y ago
    So hypothetically, if it was roughly 2-3x the cost to deploy into space, there may be situations where it would be viable. No land usage on the ground, no maintenance, power could be beamed to various parts of the globe as its needed, etc. Ground based solar still wins watts/$ probably, but the better comparison might be versus small modular nuclear reactors. I think costs are close to the smaller reactors, but larger reactors are still more cost efficient. It would be like an SMR that did not require regulatory approvals and could cover a larger area as needed.
    - xp84 2y ago
      No maintenance? Really? One ‘aiming’ motor goes bad, and this thing could easily fry a long strip of the earth when it loses its lock on its ground station. I don’t think I want such an Elon Musk type of promise as “no maintenance” in this situation. Everything needs maintenance, and while space does different things to machines than air does, they still wear.
      - spiralk 2y ago
        This video goes into some details about one proposed design: https://www.youtube.com/watch?v=YX1bcNqhhi8 https://www.youtube.com/watch?v=YX1bcNqhhi8. The intensity of the beam would not be a concern. There is no "aiming" motor in this design, its using a phased array. Ground solar panels need relatively frequent cleaning due to dust, weather, and plants/animals in some areas. In space the biggest maintenance costs are gone. With the $10-$100/kg launch costs refueling would not be that expensive. Micrometeorites may be an issue, but if the rate of micrometeorite impact is low enough it may not be a concern. The 60-year costs of ground solar panels are actually worse than a large nuclear power plant due to the maintenance, so it is a significant part. Space solar may not be effective initially, but I think it could have its place similar to SMRs. Power could be generated 24/7. The ability to allocate power as needed across a whole hemisphere would allow us to optimize power grids without megatons of power cables. These could also beam power to moon bases or even mars bases eventually. Also bringing up Musk was unnecessary. The space industry is bigger than one person and many of "his" ideas predate his involvement with the industry and have teams of many scientists and engineers doing the actual work. It would be a shame to throw out ideas that could facilitate human progress simply because we didn't like one personality.
        xp84 2y ago
        I didn't mean EM himself was relevant here, I just think "no maintenance" for a device launched into the space seemed like the sort of promise he makes (specifically about how he has insisted over the years of describing his cars as 'full self driving'). TBH though I'm very much not qualified to debate about this type of technology, so I acknowledge that perhaps this could have no moving parts and if so maybe maintenance is less certain than I thought.
XorNot 2y ago
Conversely solar panels are cheap, but environmental impact statements, permitting and installation labour are not. Its not immediately obvious that a mass produced solar satellite could not scale better than thousands of individual legal jurisdictions and eco systems.
- janalsncm 2y ago
  Those things are true in the US. You don’t need to go all the way to space to find a place where solar panels can be deployed cheaply.
  - codegrappler 2y ago
    But you do need to factor in geography. Solar cells in space can be “always on and operating at peak efficiency” directly over the places that need the power, significantly reducing the need to build long distance transmission lines.

spiralk 2y ago

If SpaceX succeeds with Starship, projected launch costs to LEO could be as little as $10/kg. Even off by an order of magnitude, $100s/kg might be enough to make it viable. There are plenty of population centers where land is scarce or there are bureaucratic hurdles due to stubborn land owners.

adrianN 2y ago
A solar panel weighs like 10kg and costs about $100. Then you also need equipment to produce the microwaves, fuel and an engine to keep the thing in place...
- spiralk 2y ago
  So hypothetically, if it was roughly 2-3x the cost to deploy into space, there may be situations where it would be viable. No land usage on the ground, no maintenance, power could be beamed to various parts of the globe as its needed, etc. Ground based solar still wins watts/$ probably, but the better comparison might be versus small modular nuclear reactors. I think costs are close to the smaller reactors, but larger reactors are still more cost efficient. It would be like an SMR that did not require regulatory approvals and could cover a larger area as needed.
  - xp84 2y ago
    No maintenance? Really? One ‘aiming’ motor goes bad, and this thing could easily fry a long strip of the earth when it loses its lock on its ground station. I don’t think I want such an Elon Musk type of promise as “no maintenance” in this situation. Everything needs maintenance, and while space does different things to machines than air does, they still wear.
    - spiralk 2y ago
      This video goes into some details about one proposed design: https://www.youtube.com/watch?v=YX1bcNqhhi8 https://www.youtube.com/watch?v=YX1bcNqhhi8. The intensity of the beam would not be a concern. There is no "aiming" motor in this design, its using a phased array. Ground solar panels need relatively frequent cleaning due to dust, weather, and plants/animals in some areas. In space the biggest maintenance costs are gone. With the $10-$100/kg launch costs refueling would not be that expensive. Micrometeorites may be an issue, but if the rate of micrometeorite impact is low enough it may not be a concern. The 60-year costs of ground solar panels are actually worse than a large nuclear power plant due to the maintenance, so it is a significant part. Space solar may not be effective initially, but I think it could have its place similar to SMRs. Power could be generated 24/7. The ability to allocate power as needed across a whole hemisphere would allow us to optimize power grids without megatons of power cables. These could also beam power to moon bases or even mars bases eventually. Also bringing up Musk was unnecessary. The space industry is bigger than one person and many of "his" ideas predate his involvement with the industry and have teams of many scientists and engineers doing the actual work. It would be a shame to throw out ideas that could facilitate human progress simply because we didn't like one personality.
      - xp84 2y ago
        I didn't mean EM himself was relevant here, I just think "no maintenance" for a device launched into the space seemed like the sort of promise he makes (specifically about how he has insisted over the years of describing his cars as 'full self driving'). TBH though I'm very much not qualified to debate about this type of technology, so I acknowledge that perhaps this could have no moving parts and if so maybe maintenance is less certain than I thought.

XorNot 2y ago

Conversely solar panels are cheap, but environmental impact statements, permitting and installation labour are not. Its not immediately obvious that a mass produced solar satellite could not scale better than thousands of individual legal jurisdictions and eco systems.

janalsncm 2y ago
Those things are true in the US. You don’t need to go all the way to space to find a place where solar panels can be deployed cheaply.
- codegrappler 2y ago
  But you do need to factor in geography. Solar cells in space can be “always on and operating at peak efficiency” directly over the places that need the power, significantly reducing the need to build long distance transmission lines.