5 ms·

This is really important. If you can improve conduction efficiency by a percent or two (let alone lossless) you can put solar panels on the other side of the pl

This is really important. If you can improve conduction efficiency by a percent or two (let alone lossless) you can put solar panels on the other side of the planet and solve global warming in a pinch by piping power to the dark side. Right now it's about 3% at 100kV iirc which translates to ~40% losses best case which, while almost financially feasible, would also cook the planet in a toaster oven. :P

stretchwithme 10y ago
might be a pretty long wire. Is that going to be cheaper than the solar energy microwaved from space?
- Zardoz84 10y ago
  Nobody would build it
  - roywiggins 10y ago
    More to the point, it starts to look like a space based death ray, which might make other nations a bit nervous...
- SapphireSun 10y ago
  Beamed energy is much less efficient right now. Wires are long, but we build long wires today. Maintenance will be a pain, but hey at least we'd have a planet. EDIT: If you want to see my back of the envelope calculations you can check out the second half of this article I wrote: https://medium.com/@willsilversmith/the-future-requires-unity-b78b65ad8e37#.xp119418f https://medium.com/@willsilversmith/the-future-requires-unit...
- jp555 10y ago
  What's the difference between space-based directed energy transmission and building-vaporizing laser space weapons?
  - Vendan 10y ago
    Nothing!!!! MUAHAHAHAHAHA!
  - VLM 10y ago
    "solar level" power density, even ten times solar level power density, is still maybe a factor of a million too low to vaporize buildings. Note that a 2x solar energy flux beam would still be an interesting tactical or strategic weapon. It wouldn't melt or burn anything directly but you could make winter streets very comfortable for protestors, or make summer streets intolerably hot for protestors. Or you could boil off water quicker than letting the sun do it itself, which is nice after a snow storm and not so nice during a drought. There are a variety of interesting optical resolution limits such that its physically impossible to accidentally turn a "warms up a couple square miles" mirror into a death ray of doom. Note that like 50 years ago people were pimping 90+% effective microwave antennas... the ground station work was done decades ago and its cheap. Now how you get a multi-megawatt continuous microwave magnetron in orbit and powered is the hard part.
    - jp555 10y ago
      super interesting thx! I didn't think of larger-area, lower intensity beam as an option. Now it's got me thinking of other ideas like adding a few months of growing season to northern & southern farms, which sounds like a cover story of Popular Science magazine from the 70s :D
- Dylan16807 10y ago
  Define "microwaved from space". Are you talking about the power production, or the power transmission? If you're talking about production, it's always going to be stupendously cheaper to install solar panels on the ground. If you're talking about transmission, just look into why we don't already use microwaves for bulk power transmission. One cable can carry gigawatts and lose a couple percent per thousand kilometers. You could go a third of the way around the planet at 75% efficiency. Microwaves are at 75% efficiency to transmit halfway across a room. They're dangerous at high power, and even then your capacity per dish is not going to be very much. Focusing it at such an enormous distance is not going to be easy, and there are extra losses when it travels through the atmosphere.
MertsA 10y ago
>would also cook the planet in a toaster oven. That energy is normally converted to heat anyways so it's not like it's that much hotter. Solar panels are going to absorb more light than vegetation would but either way, it's not a huge difference one way or another.
- SapphireSun 10y ago
  I think a lot of energy gets either bounced into space (desert) or turned into a weird thing like a protein or complex structure which takes away some of the heat by storing it in chemical bonds. Deserts are where you'd put solar panels and i'd gather that vegetation is pretty efficient with absorbed energy. There's a good chance it'd be net positive for heat.
  - labster 10y ago
    It's the former; most energy is returned to space. Not that much energy is stored in biological systems on the macro scale -- heat waves cause wildfire, not the reverse. Besides, to keep homeostasis or anything resembling it, energy in needs to roughly equal energy out. Also vegetation is pretty terrible with absorbed energy efficiency. I mean, for goodness sake's it's green, the color right in the peak of the Sun's spectrum. That means the best wavelengths are all reflected. This is a feature, as it really helps quite a bit with keeping albedo higher, even in dark forests, for the purposes of preventing runaway global warming.
    - fpoling 10y ago
      The leafs are green because it improves over all efficiency of photosynthesis across spectrum, http://m.pcp.oxfordjournals.org/content/50/4/684.full http://m.pcp.oxfordjournals.org/content/50/4/684.full

stretchwithme 10y ago

might be a pretty long wire. Is that going to be cheaper than the solar energy microwaved from space?

Zardoz84 10y ago
Nobody would build it
- roywiggins 10y ago
  More to the point, it starts to look like a space based death ray, which might make other nations a bit nervous...
SapphireSun 10y ago
Beamed energy is much less efficient right now. Wires are long, but we build long wires today. Maintenance will be a pain, but hey at least we'd have a planet. EDIT: If you want to see my back of the envelope calculations you can check out the second half of this article I wrote: https://medium.com/@willsilversmith/the-future-requires-unity-b78b65ad8e37#.xp119418f https://medium.com/@willsilversmith/the-future-requires-unit...
jp555 10y ago
What's the difference between space-based directed energy transmission and building-vaporizing laser space weapons?
- Vendan 10y ago
  Nothing!!!! MUAHAHAHAHAHA!
- VLM 10y ago
  "solar level" power density, even ten times solar level power density, is still maybe a factor of a million too low to vaporize buildings. Note that a 2x solar energy flux beam would still be an interesting tactical or strategic weapon. It wouldn't melt or burn anything directly but you could make winter streets very comfortable for protestors, or make summer streets intolerably hot for protestors. Or you could boil off water quicker than letting the sun do it itself, which is nice after a snow storm and not so nice during a drought. There are a variety of interesting optical resolution limits such that its physically impossible to accidentally turn a "warms up a couple square miles" mirror into a death ray of doom. Note that like 50 years ago people were pimping 90+% effective microwave antennas... the ground station work was done decades ago and its cheap. Now how you get a multi-megawatt continuous microwave magnetron in orbit and powered is the hard part.
  - jp555 10y ago
    super interesting thx! I didn't think of larger-area, lower intensity beam as an option. Now it's got me thinking of other ideas like adding a few months of growing season to northern & southern farms, which sounds like a cover story of Popular Science magazine from the 70s :D
Dylan16807 10y ago
Define "microwaved from space". Are you talking about the power production, or the power transmission? If you're talking about production, it's always going to be stupendously cheaper to install solar panels on the ground. If you're talking about transmission, just look into why we don't already use microwaves for bulk power transmission. One cable can carry gigawatts and lose a couple percent per thousand kilometers. You could go a third of the way around the planet at 75% efficiency. Microwaves are at 75% efficiency to transmit halfway across a room. They're dangerous at high power, and even then your capacity per dish is not going to be very much. Focusing it at such an enormous distance is not going to be easy, and there are extra losses when it travels through the atmosphere.

MertsA 10y ago

>would also cook the planet in a toaster oven. That energy is normally converted to heat anyways so it's not like it's that much hotter. Solar panels are going to absorb more light than vegetation would but either way, it's not a huge difference one way or another.

SapphireSun 10y ago
I think a lot of energy gets either bounced into space (desert) or turned into a weird thing like a protein or complex structure which takes away some of the heat by storing it in chemical bonds. Deserts are where you'd put solar panels and i'd gather that vegetation is pretty efficient with absorbed energy. There's a good chance it'd be net positive for heat.
- labster 10y ago
  It's the former; most energy is returned to space. Not that much energy is stored in biological systems on the macro scale -- heat waves cause wildfire, not the reverse. Besides, to keep homeostasis or anything resembling it, energy in needs to roughly equal energy out. Also vegetation is pretty terrible with absorbed energy efficiency. I mean, for goodness sake's it's green, the color right in the peak of the Sun's spectrum. That means the best wavelengths are all reflected. This is a feature, as it really helps quite a bit with keeping albedo higher, even in dark forests, for the purposes of preventing runaway global warming.
  - fpoling 10y ago
    The leafs are green because it improves over all efficiency of photosynthesis across spectrum, http://m.pcp.oxfordjournals.org/content/50/4/684.full http://m.pcp.oxfordjournals.org/content/50/4/684.full