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Solar panels are not reflective
by baybal2 5y ago
Solar panels are not reflective
- mirashii 5y agoSolar panels have an albedo of ~0.3. Asphalt around ~0.05. That makes it 6x better in terms of heat reflected back right out the gate. There are many other, more complicated factors that make this even better in practice.
- frosted-flakes 5y agoNo, they absorb the sunlight and turn it into electricity.
- baq 5y agoBut because they absorb sunlight, they get hot. Basic thermodynamics. Still better than asphalt.
- frosted-flakes 5y agoTo a point, because 100%-efficient panels don't exist. If they did, then my naive understanding is that they wouldn't get hot.
- starbase 5y agoPerfectly black and doesn't get hot in the sun. I love it.
- baq 5y agoagain, thermodynamics: > The maximum theoretical efficiency calculated is 86.8% for a stack of an infinite number of cells, using the incoming concentrated sunlight radiation. When the incoming radiation comes only from an area of the sky the size of the sun, the efficiency limit drops to 68.7%. https://en.wikipedia.org/wiki/Solar_cell_efficiency#Thermodynamic_efficiency_limit_and_infinite-stack_limit https://en.wikipedia.org/wiki/Solar_cell_efficiency#Thermody...
- frosted-flakes 5y agoThat's why I said that 100% efficient panels don't exist.
- thombat 5y agoIf there is to be a hot surface it's better that it's the far side of a panel a few metres above ground than the asphalt beneath your feet.
- jandrese 5y agoThey're turning that energy from the sun into electricity instead of local heating. Of course solar panels are only 20% efficient or so and thus will still heat up, but not as much as if the panels were not generating energy. Damn thermodynamics, you can't even break even.