5 ms·

Short term solution: natural gas peaker plants could be repurposed to provide power during lulls in production (better than most fossil fuels, but very expensiv

Short term solution: natural gas peaker plants could be repurposed to provide power during lulls in production (better than most fossil fuels, but very expensive and still produce greenhouse gases, so can't be the solution for long) Medium term solution: long-distance transmission, overprovision, and even more grid-scale storage (whole continents don't get cloudy & calm at once for long periods of time) Potential long term solution: space-based solar (power is 24/7, just need lots of landing locations + distribution, because microwaves are attenuated by atmospheric moisture) Edit: tl;dr is that for the issues, there are many potential solutions

WanderPanda 7y ago
Wont introducing net energy to the earth add to the warming?
- esotericn 7y ago
  Not substantially. The issue is that energy that would normally escape does not.
- riffraff 7y ago
  I may be incorrect, but space based solar would catch energy that would reach the earth anyway, basically shading us. So it would probably be more or less adding the same energy, but sending it to the ground rather than dispersing some in the stratosphere.
  - pfdietz 7y ago
    That's incorrect, sorry.
    - riffraff 7y ago
      ok, but can you explain why, please?
      - pfdietz 7y ago
        The satellites would be in wide orbits (typically imagined to be geostationary) that would almost never be on the line between the Sun and the Earth. And if they were between the Sun and Earth, they couldn't beam power to the Earth's night side.
- SECProto 7y ago
  Yes, it would (though an interesting comparison would be ground-based renewables vs. carbon capturing land use + space based solar). Another possible long-term, space-based alternative to reduce global warming would be space-based manufacturing. It's equally as plausible - if the economics work for space-based solar, it means either space-based-manufacturing is a thing, or launch costs have dramatically lowered
- maxerickson 7y ago
  Barely. The temperature of the earth is a function of the balance between energy inputs and energy outputs. The solar input is much much more power than total human utilization, so adding "human" amounts of power won't shift the balance very much.
  - kragen 7y ago
    We're talking “long-term” here, as in when the humans are using over a thousand times as much energy as they are now, so that it's cheaper to launch solar panels into fricking space than to upgrade the ocean-carpeting solar panel rafts blanketing much of the oceans to be 90% rather than 75% efficient. So yes, even before that point, solar energy harvesting will begin to have noticeable climatic effects.
    - maxerickson 7y ago
      1000x would make human use ~20% of the earth system, but earth side solar wouldn't get counted twice, so it would be less. I agree that would have an impact, but I doubt the other poster was imagining the 1000x scenario. The numbers are something like 20 terawatts for current human utilization and 100 petawatts for solar power.
      - kragen 7y ago
        Yeah, that's about what I calculated in https://news.ycombinator.com/item?id=20426368 https://news.ycombinator.com/item?id=20426368 — 130 petawatts of terrestrial insolation and 18 terawatts of world marketed energy consumption. I think solar panels will tend to have lower albedo than the surfaces they shade (sunlight they reflect is not available for energy production, and even the 16%-efficient ones that are common today are pretty black), especially before the humans start floating them on oceans. Essentially all the energy they successfully harvest will later be converted to heat on Earth. So they will represent a positive thermal forcing in the climate system. I don't know what you mean about getting counted twice? I don't know why anyone would propose orbiting solar panels when it's still easy to put solar panels on deserts. So I assumed that was what they were imagining, even though that's not a long-term scenario; it could happen before 2089, which is very short-term.

WanderPanda 7y ago

Wont introducing net energy to the earth add to the warming?

esotericn 7y ago
Not substantially. The issue is that energy that would normally escape does not.
riffraff 7y ago
I may be incorrect, but space based solar would catch energy that would reach the earth anyway, basically shading us. So it would probably be more or less adding the same energy, but sending it to the ground rather than dispersing some in the stratosphere.
- pfdietz 7y ago
  That's incorrect, sorry.
  - riffraff 7y ago
    ok, but can you explain why, please?
    - pfdietz 7y ago
      The satellites would be in wide orbits (typically imagined to be geostationary) that would almost never be on the line between the Sun and the Earth. And if they were between the Sun and Earth, they couldn't beam power to the Earth's night side.
SECProto 7y ago
Yes, it would (though an interesting comparison would be ground-based renewables vs. carbon capturing land use + space based solar). Another possible long-term, space-based alternative to reduce global warming would be space-based manufacturing. It's equally as plausible - if the economics work for space-based solar, it means either space-based-manufacturing is a thing, or launch costs have dramatically lowered
maxerickson 7y ago
Barely. The temperature of the earth is a function of the balance between energy inputs and energy outputs. The solar input is much much more power than total human utilization, so adding "human" amounts of power won't shift the balance very much.
- kragen 7y ago
  We're talking “long-term” here, as in when the humans are using over a thousand times as much energy as they are now, so that it's cheaper to launch solar panels into fricking space than to upgrade the ocean-carpeting solar panel rafts blanketing much of the oceans to be 90% rather than 75% efficient. So yes, even before that point, solar energy harvesting will begin to have noticeable climatic effects.
  - maxerickson 7y ago
    1000x would make human use ~20% of the earth system, but earth side solar wouldn't get counted twice, so it would be less. I agree that would have an impact, but I doubt the other poster was imagining the 1000x scenario. The numbers are something like 20 terawatts for current human utilization and 100 petawatts for solar power.
    - kragen 7y ago
      Yeah, that's about what I calculated in https://news.ycombinator.com/item?id=20426368 https://news.ycombinator.com/item?id=20426368 — 130 petawatts of terrestrial insolation and 18 terawatts of world marketed energy consumption. I think solar panels will tend to have lower albedo than the surfaces they shade (sunlight they reflect is not available for energy production, and even the 16%-efficient ones that are common today are pretty black), especially before the humans start floating them on oceans. Essentially all the energy they successfully harvest will later be converted to heat on Earth. So they will represent a positive thermal forcing in the climate system. I don't know what you mean about getting counted twice? I don't know why anyone would propose orbiting solar panels when it's still easy to put solar panels on deserts. So I assumed that was what they were imagining, even though that's not a long-term scenario; it could happen before 2089, which is very short-term.