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> Desert solar will be abandoned in the near future. Why is that? Isn't it the best place to build area-hungry, sun-hungry equipment?? > Orbiting solar, for t

> Desert solar will be abandoned in the near future. Why is that? Isn't it the best place to build area-hungry, sun-hungry equipment?? > Orbiting solar, for terrestrial power, will not happen at all. So you don't believe that a Dyson Sphere (or Swarm) is the best way to non-destructively accomodate an energy-hungry advanced civilization?

2143 4y ago
> Why is that? Isn't it the best place to build area-hungry, sun-hungry equipment?? Dust is a problem. Efficiency reduces once there's a layer of dust on top of the panels. Could happen anywhere, but I imagine the problem would be more pronounced deserts, with its sands and winds.
- henearkr 4y ago
  Ok but still, if you build a gigantic solar panel field, and with dust let's suppose it reduces the energy output to 20%, isn't 20% of a huge lot still a huge lot? Moreover there are probably solutions to remove the dust when it becomes too thick, like to rotate the panels to let it drop off.
  - 2143 4y ago
    It'll keep accumulating and won't stay at 20%. Just so it's clear, dust is a problem regardless of whether it's in a desert or an urban area. > Moreover there are probably solutions to remove the dust when it becomes too thick, like to rotate the panels to let it drop off. Too much complexity. Moving parts that can fail for whatever reason. Sand can get into the rotation mechanism and clog the whole thing. Too many things that can go wrong. Costs will be high. I know that in some non-desert places they use water to clean the panels at regular intervals, but that's probably a bad idea in deserts because water and sand might mix to form mud. And where are you going to get water from? Like, you might have to spend a significant fraction of the generated power to pump water... You see where this is going, right? Too much hassles.
    - henearkr 4y ago
      But you don't see dust accumulating indefinitely on roofs, do you? Why would it on solar panels? (granted you install them with a slope and at some height on a pole). As for maintenance of a mechanism, we do not shy away very large off-shore wind turbine fields (or also in-shore, if you want to reply that there is little sand at sea), so I don't really see it as a compelling argument.
      - 2143 4y ago
        > But you don't see dust accumulating indefinitely on roofs, do you? I do, actually.
        henearkr 4y ago
        Ok, my bad then. In which region? I've never seen people shoveling off kilos of dust from their roof like they would do for e.g. snow. For example the wind bringing Sahara dust to Southern Europe only leaves a thin layer of dust, it would never reach anywhere close to 0.2 mm. That still leaves a lot of light going through, so maybe it becomes my hypothetical 20% (maybe roughly the same as a very cloudy weather). Precision: I'm speaking of a sloppy roof, of course, not a flat one.
        deleted 4y ago
        [deleted]
        2143 4y ago
        > In which region? South Asia. > I've never seen people shoveling off kilos of dust from their roof like they would do for e.g. snow. And I've never seen people shoveling off snow from their roof. Because it doesn't snow here. Doesn't mean it doesn't snow anywhere in the world. Same thing with the dust. You have snow. We have dust. You're lucky to live in a place that's not dusty. Tangential anecdote: the replacement intervals of air filters of cars (including those that are sold in both USA and here) are drastically different. Over here for most cars the filters should be changed at around 10000 km. In USA it's more like 24000 km (for especially dusty conditions) to 48000 km for those same cars. (I picked USA because it's a random developed country. I do not assume you're from there.) How about indoors? We sweep/vaccum away plenty of dust. Do you people not have to do that? > That still leaves a lot of light going through, so maybe it becomes my hypothetical 20% (maybe roughly the same as a very cloudy weather). We don't have to speculate; there's studies on this. I'm posting a couple of links I skimmed through: 1. https://news.mit.edu/2022/solar-panels-dust-magnets-0311 https://news.mit.edu/2022/solar-panels-dust-magnets-0311 2. https://www.nrel.gov/news/features/2021/scientists-studying-solar-try-solving-a-dusty-problem.html https://www.nrel.gov/news/features/2021/scientists-studying-... From the 2nd link: "The energy lost annually from soiling amounts to as much as 7% in parts of the United States to as high as 50% in the Middle East." Middle-east is all desert, and there's as much as 50% energy loss there.
ncmncm 4y ago
Farmland and pasture are also area-hungry, but nearer by populations. Solar (and wind) co-exist synergetically with those. Likewise, with reservoirs and canals. Vertical fence-rows of bifacial panels, aligned N-S, are minimally disruptive of existing farm methods, and harvest morning and afternoon sun while relieving crops from heat stress and water loss. They do not accumulate dust. Peppers and tomatoes may get 2x-3x yield, so protected. Panels on greenhouse roofs are also helpful. Some crops do best directly under horizontal panels, using morning and afternoon light, protected by them from storm rain and hail. In pasture, herds keep weeds off panels. * * * Aneutronic fusion will be solved long before we need much power in space. The current fusion work has no future except insofar as it develops plasma management tech.
- henearkr 4y ago
  I'm not speaking of power in space, but power produced in space. It can be transmitted to Earth. Also, you speak about vertical solar panels, do you know that then you get a worse efficiency than with slightly reclined panels, which would neither accumulate much dust, especially if they can also occasionally rotate on their supporting pole? As for aneutronic fusion, it is still much more limited than space solar, because it relies on supplies of boron. Of course not on a short time scale, but my allusion to the Dyson Sphere was a long term speculation, not a short term one.
  - ncmncm 4y ago
    > power in space, but power produced in space ... transmitted to Earth ... will not happen. Efficiency decreases in importance as panel cost continues on down the steep exponential learning curve. Other considerations become increasingly important, such as mounting cost. Fenceposts are cheap. Boron is very plentiful, and not much would anyway be needed. By the time we need more we will be equipped to make it or use something else. In the long term, being found to still depend on solar irradiation for power would be distinctly embarrassing. In any case, all the action will be out in the Kuiper Belt where the truly irreducibly valuable commodities cold and room are abundant, and solar irradiance is hardly noticeable.

2143 4y ago

> Why is that? Isn't it the best place to build area-hungry, sun-hungry equipment?? Dust is a problem. Efficiency reduces once there's a layer of dust on top of the panels. Could happen anywhere, but I imagine the problem would be more pronounced deserts, with its sands and winds.

henearkr 4y ago
Ok but still, if you build a gigantic solar panel field, and with dust let's suppose it reduces the energy output to 20%, isn't 20% of a huge lot still a huge lot? Moreover there are probably solutions to remove the dust when it becomes too thick, like to rotate the panels to let it drop off.
- 2143 4y ago
  It'll keep accumulating and won't stay at 20%. Just so it's clear, dust is a problem regardless of whether it's in a desert or an urban area. > Moreover there are probably solutions to remove the dust when it becomes too thick, like to rotate the panels to let it drop off. Too much complexity. Moving parts that can fail for whatever reason. Sand can get into the rotation mechanism and clog the whole thing. Too many things that can go wrong. Costs will be high. I know that in some non-desert places they use water to clean the panels at regular intervals, but that's probably a bad idea in deserts because water and sand might mix to form mud. And where are you going to get water from? Like, you might have to spend a significant fraction of the generated power to pump water... You see where this is going, right? Too much hassles.
  - henearkr 4y ago
    But you don't see dust accumulating indefinitely on roofs, do you? Why would it on solar panels? (granted you install them with a slope and at some height on a pole). As for maintenance of a mechanism, we do not shy away very large off-shore wind turbine fields (or also in-shore, if you want to reply that there is little sand at sea), so I don't really see it as a compelling argument.
    - 2143 4y ago
      > But you don't see dust accumulating indefinitely on roofs, do you? I do, actually.
      - henearkr 4y ago
        Ok, my bad then. In which region? I've never seen people shoveling off kilos of dust from their roof like they would do for e.g. snow. For example the wind bringing Sahara dust to Southern Europe only leaves a thin layer of dust, it would never reach anywhere close to 0.2 mm. That still leaves a lot of light going through, so maybe it becomes my hypothetical 20% (maybe roughly the same as a very cloudy weather). Precision: I'm speaking of a sloppy roof, of course, not a flat one.
        deleted 4y ago
        [deleted]
        2143 4y ago
        > In which region? South Asia. > I've never seen people shoveling off kilos of dust from their roof like they would do for e.g. snow. And I've never seen people shoveling off snow from their roof. Because it doesn't snow here. Doesn't mean it doesn't snow anywhere in the world. Same thing with the dust. You have snow. We have dust. You're lucky to live in a place that's not dusty. Tangential anecdote: the replacement intervals of air filters of cars (including those that are sold in both USA and here) are drastically different. Over here for most cars the filters should be changed at around 10000 km. In USA it's more like 24000 km (for especially dusty conditions) to 48000 km for those same cars. (I picked USA because it's a random developed country. I do not assume you're from there.) How about indoors? We sweep/vaccum away plenty of dust. Do you people not have to do that? > That still leaves a lot of light going through, so maybe it becomes my hypothetical 20% (maybe roughly the same as a very cloudy weather). We don't have to speculate; there's studies on this. I'm posting a couple of links I skimmed through: 1. https://news.mit.edu/2022/solar-panels-dust-magnets-0311 https://news.mit.edu/2022/solar-panels-dust-magnets-0311 2. https://www.nrel.gov/news/features/2021/scientists-studying-solar-try-solving-a-dusty-problem.html https://www.nrel.gov/news/features/2021/scientists-studying-... From the 2nd link: "The energy lost annually from soiling amounts to as much as 7% in parts of the United States to as high as 50% in the Middle East." Middle-east is all desert, and there's as much as 50% energy loss there.

ncmncm 4y ago

Farmland and pasture are also area-hungry, but nearer by populations. Solar (and wind) co-exist synergetically with those. Likewise, with reservoirs and canals. Vertical fence-rows of bifacial panels, aligned N-S, are minimally disruptive of existing farm methods, and harvest morning and afternoon sun while relieving crops from heat stress and water loss. They do not accumulate dust. Peppers and tomatoes may get 2x-3x yield, so protected. Panels on greenhouse roofs are also helpful. Some crops do best directly under horizontal panels, using morning and afternoon light, protected by them from storm rain and hail. In pasture, herds keep weeds off panels. * * * Aneutronic fusion will be solved long before we need much power in space. The current fusion work has no future except insofar as it develops plasma management tech.

henearkr 4y ago
I'm not speaking of power in space, but power produced in space. It can be transmitted to Earth. Also, you speak about vertical solar panels, do you know that then you get a worse efficiency than with slightly reclined panels, which would neither accumulate much dust, especially if they can also occasionally rotate on their supporting pole? As for aneutronic fusion, it is still much more limited than space solar, because it relies on supplies of boron. Of course not on a short time scale, but my allusion to the Dyson Sphere was a long term speculation, not a short term one.
- ncmncm 4y ago
  > power in space, but power produced in space ... transmitted to Earth ... will not happen. Efficiency decreases in importance as panel cost continues on down the steep exponential learning curve. Other considerations become increasingly important, such as mounting cost. Fenceposts are cheap. Boron is very plentiful, and not much would anyway be needed. By the time we need more we will be equipped to make it or use something else. In the long term, being found to still depend on solar irradiation for power would be distinctly embarrassing. In any case, all the action will be out in the Kuiper Belt where the truly irreducibly valuable commodities cold and room are abundant, and solar irradiance is hardly noticeable.