5 ms·

This is good to hear. I assume location must play a large part in this? Solar must be more cost-effective in, say, the Mojave desert, than it is in Alaska. I s

by briga 6y ago

This is good to hear. I assume location must play a large part in this? Solar must be more cost-effective in, say, the Mojave desert, than it is in Alaska. I sometimes wonder if the widespread adoption of solar is going to have an environmental impact that isn't immediately apparent. Every solar panel you put on the ground is going to take up solar energy that could otherwise be absorbed by a plant, which in turn means that plant can't absorb carbon from the atmosphere. So unless we just limit ourselves to rooftop solar panels there's sure to be some sort of environmental impact if we just switch all our energy to solar.

xnx 6y ago
Possibly, though I don't think solar panels will ever catch up to the amount of pavement there is.
m463 6y ago
I've wondered about that too (competing with nature for the sun) but I think just putting panels on the roof or over the parking lot would probably address 95% of the problem. Along similar lines, I've wondered if solar panels will start to look like pine trees at some point.
- briga 6y ago
  >I've wondered if solar panels will start to look like pine trees at some point. Interesting thought, but I'm not sure there same factors that led to plant evolution will play out with solar panels. Plants reaching up into the air was a direct response to competition with other types of plants. Presumably the same sort of competition won't be necessary with solar panels. I'm sure nature still has a lot of inspiration we can draw from for creating new types of solar panels, but my guess is that the most efficient surface for collecting solar energy is the flat square design we see today.
  - m463 6y ago
    You're probably right. Aim fixed panels for the brightest part of the day and use batteries and that will probably solve most problems. What I think is interesting abouts trees is that they can take in energy even when the sun is low on the horizon, they have good ventilation so they don't overheat, and they work no matter what angle the sun is facing. The giant sequoias get a lot of their moisture directly from the air. Maybe we could add functions to our "tree-shaped solar panels" like fresh water gathering and climate control heat exchange.
kragen 6y ago
> I assume location must play a large part in this? Solar must be more cost-effective in, say, the Mojave desert, than it is in Alaska. Yes, each peak kilowatt of utility-scale solar produces about 240 watts average in Arizona, 140 in Maine, and 100 in Germany ("capacity factors" of 24%, 14%, and 10%). I assume the number for Alaska would be even lower. > Every solar panel you put on the ground is going to take up solar energy that could otherwise be absorbed by a plant, which in turn means that plant can't absorb carbon from the atmosphere. Yes, and also it will reflect less heat back into space than the plant or bare dirt would, locally raising the temperature. These will start to be important problems when the quantity of power produced by solar panels is about 100 times larger than current world marketed energy consumption. I expect that this will happen in about 30 years. However, merely switching all our energy to solar will have an effect that's about 100 times too small to matter.
- brundolf 6y ago
  > it will reflect less heat back into space than the plant or bare dirt would, locally raising the temperature I'm not sure this checks out... the light gets absorbed, but the energy doesn't get turned into heat, it gets turned into electricity. If anything, where it's covering up concrete or asphalt it should reduce the conversion of sunlight to local heat.
  - Nullabillity 6y ago
    Some of it turns into electricity, some of it is wasted (turned into heat). And the whole point is that the electricity gets used at some point, turning into heat, computation (heat), light (heat), or motion (heat). And of course, you also have transmission losses (heat) along the way!
  - kragen 6y ago
    A 21% efficient solar panel reflects about 9% of the light, turns about 60% of it into heat immediately, and turns the other 21% into heat shortly afterwards, perhaps somewhere else, when the power the solar cell generates is dissipated by, for example, an electric motor or lightbulb.
  - 6y ago
Someone 6y ago
https://news.mit.edu/2011/energy-scale-part3-1026 https://news.mit.edu/2011/energy-scale-part3-1026: “A total of 173,000 terawatts (trillions of watts) of solar energy strikes the Earth continuously. That's more than 10,000 times the world's total energy use“ That article is from 2011, but I think it’s a very safe bet that factor is still more than 1,000 today. Also, I would think about every solar panel you put on the ground reflects less energy into space than the ground did.
griffinkelly 6y ago
I've read a few articles that these solar farms are creating their own microclimates, and particularly in already warm areas can have significant impacts to wildlife with the local temperature increasing in the range of 3-4 degrees C: https://www.nature.com/articles/srep35070 https://www.nature.com/articles/srep35070
jxidjhdhdhdhfhf 6y ago
One possibility is to use farmland or grazing land. You can pick crops that do better in part shade and then place solar panels over them. If done right it could have a beneficial effect on crop growth while at the same time earning extra money.
- fabatka 6y ago
  But then harvesting would be significantly harder, no? At least in the way I imagine this.
  - jxidjhdhdhdhfhf 6y ago
    I'm not sure but certainly it would depend on the crop as different harvesting methods are used for different crops. For example, panels could be built so cows can graze under them or for handpicked crops so that people can walk under them.
    - imtringued 6y ago
      You're right. Just build a "solar roof". Basically a solar panel on four legs.
- Danieru 6y ago
  This is a allowed but semi-rare technique in Japan. Rare because of the capital costs to built the panels. Certain high end plants, such as tea, prefer the shade.
  - imtringued 6y ago
    It would be interesting in northern Africa. Install soil erosion blankets and then put solar panels on top to reduce evaporation. Trim the plant growth to increase the biomass available to the soil.
zizee 6y ago
> Solar must be more cost-effective in, say, the Mojave desert, than it is in Alaska. I don't think this was your intention, but this reminded me of something I see in so many of these conversations. In discussions about solar (and electric cars) there are always people who say "well this won't work in situation X", with an unsaid implication of "this is not the solution". It is unlikely that we will find a single solution that will be a good fit for all situations. Instead we will have many tools in our belt and apply accordingly. I know that you used alaska as an extreme, perhaps they will never get off fossil fuels. But alaska is a tiny population overall. Its the main population centers that we need to worry about, not the extremes that are hand picked to be difficult.
- someperson 6y ago
  You may be interested in the video The LED Traffic Light and the Danger of "But Sometimes!" by Technology Connections: https://www.youtube.com/watch?v=GiYO1TObNz8 https://www.youtube.com/watch?v=GiYO1TObNz8
pfdietz 6y ago
Look at the solution you get for Alaska in https://model.energy/ https://model.energy/ It's a combination of solar, wind, and hydrogen (with a little battery storage).

by briga 6y ago

xnx 6y ago

Possibly, though I don't think solar panels will ever catch up to the amount of pavement there is.

m463 6y ago

I've wondered about that too (competing with nature for the sun) but I think just putting panels on the roof or over the parking lot would probably address 95% of the problem. Along similar lines, I've wondered if solar panels will start to look like pine trees at some point.

briga 6y ago
>I've wondered if solar panels will start to look like pine trees at some point. Interesting thought, but I'm not sure there same factors that led to plant evolution will play out with solar panels. Plants reaching up into the air was a direct response to competition with other types of plants. Presumably the same sort of competition won't be necessary with solar panels. I'm sure nature still has a lot of inspiration we can draw from for creating new types of solar panels, but my guess is that the most efficient surface for collecting solar energy is the flat square design we see today.
- m463 6y ago
  You're probably right. Aim fixed panels for the brightest part of the day and use batteries and that will probably solve most problems. What I think is interesting abouts trees is that they can take in energy even when the sun is low on the horizon, they have good ventilation so they don't overheat, and they work no matter what angle the sun is facing. The giant sequoias get a lot of their moisture directly from the air. Maybe we could add functions to our "tree-shaped solar panels" like fresh water gathering and climate control heat exchange.

kragen 6y ago

> I assume location must play a large part in this? Solar must be more cost-effective in, say, the Mojave desert, than it is in Alaska. Yes, each peak kilowatt of utility-scale solar produces about 240 watts average in Arizona, 140 in Maine, and 100 in Germany ("capacity factors" of 24%, 14%, and 10%). I assume the number for Alaska would be even lower. > Every solar panel you put on the ground is going to take up solar energy that could otherwise be absorbed by a plant, which in turn means that plant can't absorb carbon from the atmosphere. Yes, and also it will reflect less heat back into space than the plant or bare dirt would, locally raising the temperature. These will start to be important problems when the quantity of power produced by solar panels is about 100 times larger than current world marketed energy consumption. I expect that this will happen in about 30 years. However, merely switching all our energy to solar will have an effect that's about 100 times too small to matter.

brundolf 6y ago
> it will reflect less heat back into space than the plant or bare dirt would, locally raising the temperature I'm not sure this checks out... the light gets absorbed, but the energy doesn't get turned into heat, it gets turned into electricity. If anything, where it's covering up concrete or asphalt it should reduce the conversion of sunlight to local heat.
- Nullabillity 6y ago
  Some of it turns into electricity, some of it is wasted (turned into heat). And the whole point is that the electricity gets used at some point, turning into heat, computation (heat), light (heat), or motion (heat). And of course, you also have transmission losses (heat) along the way!
- kragen 6y ago
  A 21% efficient solar panel reflects about 9% of the light, turns about 60% of it into heat immediately, and turns the other 21% into heat shortly afterwards, perhaps somewhere else, when the power the solar cell generates is dissipated by, for example, an electric motor or lightbulb.
- 6y ago

Someone 6y ago

https://news.mit.edu/2011/energy-scale-part3-1026 https://news.mit.edu/2011/energy-scale-part3-1026: “A total of 173,000 terawatts (trillions of watts) of solar energy strikes the Earth continuously. That's more than 10,000 times the world's total energy use“ That article is from 2011, but I think it’s a very safe bet that factor is still more than 1,000 today. Also, I would think about every solar panel you put on the ground reflects less energy into space than the ground did.

griffinkelly 6y ago

I've read a few articles that these solar farms are creating their own microclimates, and particularly in already warm areas can have significant impacts to wildlife with the local temperature increasing in the range of 3-4 degrees C: https://www.nature.com/articles/srep35070 https://www.nature.com/articles/srep35070

jxidjhdhdhdhfhf 6y ago

One possibility is to use farmland or grazing land. You can pick crops that do better in part shade and then place solar panels over them. If done right it could have a beneficial effect on crop growth while at the same time earning extra money.

fabatka 6y ago
But then harvesting would be significantly harder, no? At least in the way I imagine this.
- jxidjhdhdhdhfhf 6y ago
  I'm not sure but certainly it would depend on the crop as different harvesting methods are used for different crops. For example, panels could be built so cows can graze under them or for handpicked crops so that people can walk under them.
  - imtringued 6y ago
    You're right. Just build a "solar roof". Basically a solar panel on four legs.
Danieru 6y ago
This is a allowed but semi-rare technique in Japan. Rare because of the capital costs to built the panels. Certain high end plants, such as tea, prefer the shade.
- imtringued 6y ago
  It would be interesting in northern Africa. Install soil erosion blankets and then put solar panels on top to reduce evaporation. Trim the plant growth to increase the biomass available to the soil.

zizee 6y ago

> Solar must be more cost-effective in, say, the Mojave desert, than it is in Alaska. I don't think this was your intention, but this reminded me of something I see in so many of these conversations. In discussions about solar (and electric cars) there are always people who say "well this won't work in situation X", with an unsaid implication of "this is not the solution". It is unlikely that we will find a single solution that will be a good fit for all situations. Instead we will have many tools in our belt and apply accordingly. I know that you used alaska as an extreme, perhaps they will never get off fossil fuels. But alaska is a tiny population overall. Its the main population centers that we need to worry about, not the extremes that are hand picked to be difficult.

someperson 6y ago
You may be interested in the video The LED Traffic Light and the Danger of "But Sometimes!" by Technology Connections: https://www.youtube.com/watch?v=GiYO1TObNz8 https://www.youtube.com/watch?v=GiYO1TObNz8

pfdietz 6y ago

Look at the solution you get for Alaska in https://model.energy/ https://model.energy/ It's a combination of solar, wind, and hydrogen (with a little battery storage).