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Abnormal temperatures and lack of humidity caused by the heat island effect of blacktop for miles and miles in every direction. Adoption of greenspace and far

Abnormal temperatures and lack of humidity caused by the heat island effect of blacktop for miles and miles in every direction. Adoption of greenspace and far more solar panels in Phoenix could significantly cut down on this phenomena.

avalys 3y ago
What do solar panels have to do with it? What color are solar panels? Do they produce less heat island effect than "blacktop"?
- wlesieutre 3y ago
  They don’t reflect a lot of light which ordinarily means a material is absorbing all the energy and turning it to heat, but in the case of solar panels you’re turning maybe 20% of it into electricity instead
- mirashii 3y ago
  Solar panels have an albedo of ~0.3. Asphalt around ~0.05. That makes it 6x better in terms of heat reflected.
  - klyrs 3y ago
    https://en.m.wikipedia.org/wiki/Albedo#Terrestrial_albedo https://en.m.wikipedia.org/wiki/Albedo#Terrestrial_albedo Your figure for asphalt seems off. I think the more pertinent comparison would be between solar cells and undisurbed land, which have similar albedo. But thermal mass is probably even more important: ground beneath solar panels receive less thermal radiation than unshaded ground, and while solar cells get hot during the day they cool down quickly at night. Simplifying greatly, they should re-emit about half of the heat they capture to the sky, and half to the ground.
    - midoridensha 3y ago
      >I think the more pertinent comparison would be between solar cells and undisurbed land, which have similar albedo. No, that's a terrible comparison. We're talking about Phoenix here: the whole place is basically covered in asphalt, either roads or parking lots. There's no "undisturbed land" there at all.
- pvaldes 3y ago
  They can be used to power a fridge
AlotOfReading 3y ago
Have you seen metro Phoenix from higher elevation? It's far more green than the surrounding desert already. Further, PV installations worsen the heat island effect and Phoenix is one of the leading cities in the US for installation numbers.
- pengaru 3y ago
  Shading the ground beneath the solar panels should have a localized cooling effect, since the panels don't have as much thermal mass.
  - AlotOfReading 3y ago
    They do provide shade, but the panels inherently absorb solar energy and heat up. That heat doesn't have anywhere to go except the air and the urban heat island.
- upsidesinclude 3y ago
  The other comments pretty well address both of those points. I'd be glad to see more information as regards the conditions which lead to that conclusion
midoridensha 3y ago
>Adoption of greenspace and far more solar panels in Phoenix could significantly cut down on this phenomena. Well, they do have lots of green grass yards needing tons of irrigation....
- upsidesinclude 3y ago
  Completely agree, xeriscaping is far more beneficial. There are lots of natural desert grasses, lawn isn't one of them

avalys 3y ago

What do solar panels have to do with it? What color are solar panels? Do they produce less heat island effect than "blacktop"?

wlesieutre 3y ago
They don’t reflect a lot of light which ordinarily means a material is absorbing all the energy and turning it to heat, but in the case of solar panels you’re turning maybe 20% of it into electricity instead
mirashii 3y ago
Solar panels have an albedo of ~0.3. Asphalt around ~0.05. That makes it 6x better in terms of heat reflected.
- klyrs 3y ago
  https://en.m.wikipedia.org/wiki/Albedo#Terrestrial_albedo https://en.m.wikipedia.org/wiki/Albedo#Terrestrial_albedo Your figure for asphalt seems off. I think the more pertinent comparison would be between solar cells and undisurbed land, which have similar albedo. But thermal mass is probably even more important: ground beneath solar panels receive less thermal radiation than unshaded ground, and while solar cells get hot during the day they cool down quickly at night. Simplifying greatly, they should re-emit about half of the heat they capture to the sky, and half to the ground.
  - midoridensha 3y ago
    >I think the more pertinent comparison would be between solar cells and undisurbed land, which have similar albedo. No, that's a terrible comparison. We're talking about Phoenix here: the whole place is basically covered in asphalt, either roads or parking lots. There's no "undisturbed land" there at all.
pvaldes 3y ago
They can be used to power a fridge

AlotOfReading 3y ago

Have you seen metro Phoenix from higher elevation? It's far more green than the surrounding desert already. Further, PV installations worsen the heat island effect and Phoenix is one of the leading cities in the US for installation numbers.

pengaru 3y ago
Shading the ground beneath the solar panels should have a localized cooling effect, since the panels don't have as much thermal mass.
- AlotOfReading 3y ago
  They do provide shade, but the panels inherently absorb solar energy and heat up. That heat doesn't have anywhere to go except the air and the urban heat island.
upsidesinclude 3y ago
The other comments pretty well address both of those points. I'd be glad to see more information as regards the conditions which lead to that conclusion

midoridensha 3y ago

>Adoption of greenspace and far more solar panels in Phoenix could significantly cut down on this phenomena. Well, they do have lots of green grass yards needing tons of irrigation....

upsidesinclude 3y ago
Completely agree, xeriscaping is far more beneficial. There are lots of natural desert grasses, lawn isn't one of them