5 ms·

Sadly, that huge fusion plant is offline half the time for any given location on the Earth, and is severely degraded by cloudy weather. Also using it to power

Sadly, that huge fusion plant is offline half the time for any given location on the Earth, and is severely degraded by cloudy weather. Also using it to power the world will require large areas of land to be dedicated to collecting its output.

LargoLasskhyfv 6y ago
So what? I give you Space Grid ©. [1] https://en.wikipedia.org/wiki/Space-based_solar_power https://en.wikipedia.org/wiki/Space-based_solar_power edit: I don't know why that symbol doesn't show as copyleft as intended.
- bufbupa 6y ago
  That seems like it could have more difficult engineering problems than a fusion reactor! Seems like a quick way to accidentally microwave a desert into a sea of glass. Hope you don't put anything remotely near the power receiver on earth.
  - DennisP 6y ago
    Power density on the ground would be way lower than you're thinking. The leading proposals, like SPS-Alpha, put a gigawatt-scale power station in geostationary orbit. Power is beamed to ground via microwave. The receiver station has to be kilometers wide, which puts the power density low enough so birds wouldn't be harmed; even that amount of focus is only doable by sending a pilot signal from the receiver, so the beam can't trivially be redirected to other targets. Despite its size, the receiver would be inexpensive, since it's mostly wire antennae.
  - rob74 6y ago
    Hey, think positive! If microwaves prove too dangerous, and they finally do manage to build a cable from the orbital power station down to earth, they have a space elevator as well!
- mrec 6y ago
  Space advocates seem to have been going off the idea of that over the past few years. I'm not sure how much of that is due to a better appreciation of the downsides, and how much is due to the very rapid improvements we've been seeing in ground-based solar. A couple of recent (late 2019) articles from Casey Handmer: https://caseyhandmer.wordpress.com/2019/08/20/space-based-solar-power-is-not-a-thing/ https://caseyhandmer.wordpress.com/2019/08/20/space-based-so... https://caseyhandmer.wordpress.com/2019/09/20/no-really-space-based-solar-power-is-not-a-useful-idea-literature-review-edition/ https://caseyhandmer.wordpress.com/2019/09/20/no-really-spac... It's worth reading the comments too; there are some interesting points there, although I think the game-changing ones rely on new tech and/or well-developed lunar industry.
  - LargoLasskhyfv 6y ago
    Yes. I'm aware of that. But while economically usable fusion remains SciFi so far, space based solar just lacks some bootstrapping. Which seems to be more attainable as time passes. If "we" really wanted this, we could do it now because the technology is there. There is no what if like in any path to fusion. edit: especially considering all the hype about colonizing Mars, or a Moonbase.
  - pfdietz 6y ago
    Space solar is a way to get the most out of expensive PV cells. But PV is no longer expensive. It's cheaper to just overbuild on Earth and transmit energy through time (storage) rather than through space (microwaves).
barbegal 6y ago
There are other options for using the sun's energy. We can grow trees to burn, we can optimise windows and window coverings to use solar energy to heat and cool buildings, we can put solar panels in the dessert, or in the ocean, or above roads or in space (but that's not very cost effective). My go to book on energy is this one http://www.withouthotair.com/ http://www.withouthotair.com/ It gives good numbers for all the energy that we could generate from renewables and all the energy we currently use.
networkimprov 6y ago
High-altitude solar platforms: http://www.stratosolar.com/blog http://www.stratosolar.com/blog
adrianhel 6y ago
There is a lot of land in the world. And definitely have the capacity to build the supply chains. It's just that it's slow and expensive while oil, gas and nuclear is fast and cheap. We need policy changes. Or in a very ideal world, fusion.
- pfdietz 6y ago
  New solar is much cheaper than new nuclear, per kWh.
  - adrianhel 6y ago
    I did not know that. That's great!
    - pfdietz 6y ago
      It's startling how quickly this happened. Even ten years ago it wasn't true. Many people have not updated their priors yet and still think nuclear is a realistic option. At this point, nuclear is a long shot, which is why I refer to SMRs as HMRs, "Hail Mary Reactors".

LargoLasskhyfv 6y ago

So what? I give you Space Grid ©. [1] https://en.wikipedia.org/wiki/Space-based_solar_power https://en.wikipedia.org/wiki/Space-based_solar_power edit: I don't know why that symbol doesn't show as copyleft as intended.

bufbupa 6y ago
That seems like it could have more difficult engineering problems than a fusion reactor! Seems like a quick way to accidentally microwave a desert into a sea of glass. Hope you don't put anything remotely near the power receiver on earth.
- DennisP 6y ago
  Power density on the ground would be way lower than you're thinking. The leading proposals, like SPS-Alpha, put a gigawatt-scale power station in geostationary orbit. Power is beamed to ground via microwave. The receiver station has to be kilometers wide, which puts the power density low enough so birds wouldn't be harmed; even that amount of focus is only doable by sending a pilot signal from the receiver, so the beam can't trivially be redirected to other targets. Despite its size, the receiver would be inexpensive, since it's mostly wire antennae.
- rob74 6y ago
  Hey, think positive! If microwaves prove too dangerous, and they finally do manage to build a cable from the orbital power station down to earth, they have a space elevator as well!
mrec 6y ago
Space advocates seem to have been going off the idea of that over the past few years. I'm not sure how much of that is due to a better appreciation of the downsides, and how much is due to the very rapid improvements we've been seeing in ground-based solar. A couple of recent (late 2019) articles from Casey Handmer: https://caseyhandmer.wordpress.com/2019/08/20/space-based-solar-power-is-not-a-thing/ https://caseyhandmer.wordpress.com/2019/08/20/space-based-so... https://caseyhandmer.wordpress.com/2019/09/20/no-really-space-based-solar-power-is-not-a-useful-idea-literature-review-edition/ https://caseyhandmer.wordpress.com/2019/09/20/no-really-spac... It's worth reading the comments too; there are some interesting points there, although I think the game-changing ones rely on new tech and/or well-developed lunar industry.
- LargoLasskhyfv 6y ago
  Yes. I'm aware of that. But while economically usable fusion remains SciFi so far, space based solar just lacks some bootstrapping. Which seems to be more attainable as time passes. If "we" really wanted this, we could do it now because the technology is there. There is no what if like in any path to fusion. edit: especially considering all the hype about colonizing Mars, or a Moonbase.
- pfdietz 6y ago
  Space solar is a way to get the most out of expensive PV cells. But PV is no longer expensive. It's cheaper to just overbuild on Earth and transmit energy through time (storage) rather than through space (microwaves).

barbegal 6y ago

There are other options for using the sun's energy. We can grow trees to burn, we can optimise windows and window coverings to use solar energy to heat and cool buildings, we can put solar panels in the dessert, or in the ocean, or above roads or in space (but that's not very cost effective). My go to book on energy is this one http://www.withouthotair.com/ http://www.withouthotair.com/ It gives good numbers for all the energy that we could generate from renewables and all the energy we currently use.

networkimprov 6y ago

High-altitude solar platforms: http://www.stratosolar.com/blog http://www.stratosolar.com/blog

adrianhel 6y ago

There is a lot of land in the world. And definitely have the capacity to build the supply chains. It's just that it's slow and expensive while oil, gas and nuclear is fast and cheap. We need policy changes. Or in a very ideal world, fusion.

pfdietz 6y ago
New solar is much cheaper than new nuclear, per kWh.
- adrianhel 6y ago
  I did not know that. That's great!
  - pfdietz 6y ago
    It's startling how quickly this happened. Even ten years ago it wasn't true. Many people have not updated their priors yet and still think nuclear is a realistic option. At this point, nuclear is a long shot, which is why I refer to SMRs as HMRs, "Hail Mary Reactors".