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Comment by BatFastard | Hacker News Reader

Does converting sunlight to electricity reduce the amount of heat absorbed by the earth? If so, how many solar panels would be required to reduce the temp by 1 degree?

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No because when the electricity is used it creates heat.

Heat is just a frequency in the spectrum right? What percent of emissions in an LED comes out as infrared?

Uhh, IR isn't heat. Heat isn't part of the EM spectrum. Hot stuff just emits more IR.

For IR in LED bulbs. Don't know, other than inconsequential.

All will be heat after X amount of time. Where the X can be a few seconds or decades or centuries.

The more interesting thing would be the light reflected by the panels (albedo factor). This could be lower or higher than the surface these panels are placed on.

Also, the emittance of the panels at thermal wavelengths is important. What you want is a panel that converts wavelengths shorter than the bandgap cutoff at high efficiency, reflects near and mid IR at longer wavelengths, but has high emissivity in the far IR at wavelengths where the atmosphere isn't too opaque.

Not like optimising for this make much sense when we haven't even covered 1% of land yet.

Maybe our great-great-great-great grandkids can think on it, will be so disappointed if they haven't mastered terraforming yet.

Could you convert electricity into a infrared laser and beam the energy into space?

A laser beam carries no entropy, so I don't see the point of this.

Using a laser beam to dissipate heat is one of those classic hard science fiction bloopers. David Brin is one guilty party (in "Sundiver").

You can skip the solar panel entirely and just lay out mirrors, or just spray the ground with white paint.

Depending on the surface being covered it may actually increase the heat. Any electricity produced will eventually become heat. Solar panels will absorb more heat than surfaces with a high albedo where a lot is reflected back into space.

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