If all of mankind’s energy was supplied through solar panels would the effect be big enough to decrease the temperature (since light is converted in part to electricity)?
If all of mankind’s energy was supplied through solar panels would the effect be big enough to decrease the temperature (since light is converted in part to electricity)?
No. If a watt worth of sunlight hits the earth, it’s transformed into a watt of heat. If it hits a solar panel, it’s transformed into some heat and some electricity, which is then used to power something that then transformed it into heat. The only solar energy that doesn’t heat up the planet is the one that is reflected back into space, which, however, isn’t much for solar panels.
However, if you use a watt of sunlight to power your phone instead of a watt of energy you got from burning coal, this watt of energy instead stays below earth and therefore doesn’t heat up the planet. It also doesn’t release co2, which would otherwise reduce the atmosphere’s reflectivity, trapping even more sun heat on the planet.
So solar panels don’t reduce the temperature by not allowing sunlight to heat up the planet, they decrease the temperature by replacing other stuff that would otherwise heat up the planet.
Just note that the released energy of burning fossils (or nuclear) is orders of magnitude below what the sun does. It really is only the CO2 from coal (or CO2 and CH4 from natural gas, …) that does the heating, since it acts like insulation.
Yeah, that explanation is bizarre. CO2 and other greenhouse gases are the issue, not heat released from combustion. If those gases could somehow be eliminated you could burn coal and other fossil fuels without any significant consequence in terms of warming the earth. The sun is doing the overwhelming majority of heating.
Just to be pedantic CO2 absorbs bands in the infrared and reemits it, energy that otherwise could be lost to space. This is part of the reason you can’t do infrared telescopes from earth.
https://news.climate.columbia.edu/2021/02/25/carbon-dioxide-cause-global-warming/
Water is an even more powerful greenhouse gas but fortunately the earth is cool enough for it to condense back out of the atmosphere. If temps got high enough that more evaporated than condensed then you’d get a runaway greenhouse effect and we’d be truly fucked.
Your comment in pictures:
Solar panels aren’t 100% efficient though, so isn’t a bunch of it is reflected back in to space?
No, they are covered in anti-reflective coatings to minimize reflection. Most of the excess is converted to heat (as would happen if the light just hit the ground).
Huh. Well, TIL
What?
Fossil fuels are carbon.
That carbon was sequestered from the atmosphere millions of years ago.
Burning fossil fuels releases that carbon into the atmosphere, which then makes the earth hotter
Think of oil as dead dinosaurs and coal as dead trees, that’s basically what it is.
All that stuff was taken out of circulation over an insanely long timeline, and now on a very short timeline we’re digging it up and putting it back into circulation. So fast that species can’t adapt to the change and die out before they can evolve.
My highlights had nothing to do with fossil fuels.
This?
The “watt of energy” is a watt from the coal… And they’re saying to leave the coal buried and sequestered.
I assumed that was understood, so I explained how burning coal heats up the planet…
You may have not realized what you highlighted had to do with fossil fuels, but that’s just because you didn’t understand.
Which is fine, you did the right thing and asked questions.
Grammatically, coal was not the subject of that sentence. But that’s fine, I see what OP was going for.
Weird choice to downvote the person who helped you understand, but you do you I guess.
It’s definitely convinced me not to spend anytime helping you in the future though. So maybe don’t be like this to the next person, Lemmy is small and there’s only so many people to help you, eventually you’ll run out.
Plants fixing carbon also converts energy to a form that isn’t heat, so I think we should count that along with reflection as a way that solar energy doesn’t become terrestrial heat.
Correct, but not only is it extremely little, this stored energy is also quickly released again after the organism dies.
Quick in geologic time. But this is what fossil fuels are, so it’s an order of magnitude or two different than the time in which generated electricity will be used.
And you’re right, it’s very small. Everything we know is pretty small, even combined. The amount of energy the sun imparts to the Earth every day equals what humanity would use over about 12 years at current levels.
No, quickly as in years. There is no more coal or oil formed today, there are now organisms that can digest every part of organic stuff. There were none back then for example for lignin from wood, which is where we got coal from.
Isnt the energy also stored in batteries until ready to be used?
Yeah, so what? Eventually, it’ll be heat.