Can enough solar pannels decrease the global temps?

Submitted ⁨⁨1⁩ ⁨month⁩ ago⁩ by ⁨sighofannoyance@lemmy.world⁩ to ⁨[deleted]⁩

https://lemmy.world/pictrs/image/75bba409-ebca-445f-909a-e354fad112a4.webp

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)?

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Asetru@feddit.org ⁨1⁩ ⁨month⁩ ago
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.

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- Eheran@lemmy.world ⁨1⁩ ⁨month⁩ ago
  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 that does the heating, since it acts like insulation.
  
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  - deranger@sh.itjust.works ⁨1⁩ ⁨month⁩ ago
    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.
    
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- SocialMediaRefugee@lemmy.world ⁨1⁩ ⁨month⁩ ago
  
  co2, which would otherwise reduce the atmosphere’s reflectivity
  
  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.
  
  …columbia.edu/…/carbon-dioxide-cause-global-warmi…
  
  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.
  
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  - Tehdastehdas@lemmy.world ⁨1⁩ ⁨month⁩ ago
    Your comment in pictures:
    
    Image Image
    
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- credo@lemmy.world ⁨1⁩ ⁨month⁩ ago
  
  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
  
  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.
  
  What?
  
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  - givesomefucks@lemmy.world ⁨1⁩ ⁨month⁩ ago
    Fossil fuels are carbon.
    
    That carbon was requested from the atmosphere millions of years ago.
    
    Burning fossil fuels releases that carbon into the atmosphere.
    
    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 and period 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.
    
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- scarabic@lemmy.world ⁨1⁩ ⁨month⁩ ago
  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.
  
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  - Eheran@lemmy.world ⁨1⁩ ⁨month⁩ ago
    Correct, but not only is it extremely little, this stored energy is also quickly released again after the organism dies.
    
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  - mojofrododojo@lemmy.world ⁨1⁩ ⁨month⁩ ago
    when that electricity (photons absorbed by solar cells dumped into the grid) they’ll almost certainly be used in an application that generates heat, as well - data centers, phones, refrigerators, cars, they all generate heat as a byproduct of using that power.
    
    I don’t think this is in any way a problem.
    
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- Aceticon@lemmy.dbzer0.com ⁨1⁩ ⁨month⁩ ago
  Which is why if the objective was just to cool down the Earth (and ignoring that solar panels replace other sources of electricity that warm up the Earth more) just painting the ground white would be more reflective than solar panels as the white paint increases the amount of sunlight that gets reflected back to space whilst solar panels not only capture some of it as electricity (that will ultimately end up transformed into heat somewhere) but they also absorb some transforming it directly into heat (i.e. they warm up a bit).
  
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- Mongostein@lemmy.ca ⁨1⁩ ⁨month⁩ ago
  Solar panels aren’t 100% efficient though, so isn’t a bunch of it is reflected back in to space?
  
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  - oyo@lemm.ee ⁨1⁩ ⁨month⁩ ago
    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).
    
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- Quadhammer@lemmy.world ⁨1⁩ ⁨month⁩ ago
  Isnt the energy also stored in batteries until ready to be used?
  
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  - Asetru@feddit.org ⁨1⁩ ⁨month⁩ ago
    Yeah, so what? Eventually, it’ll be heat.
    
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nothacking@discuss.tchncs.de ⁨1⁩ ⁨month⁩ ago
Not directly. That electricity is converted to heat when it’s used: All devices are space heaters, some just do other things as well. Even if not used, it would still be converted to heat by the panels. There’s no getting around the conservation of energy.

In theory, we could send that power out into space as microwaves or light, but in practice the effect would be negligible. The direct heat output of every human activity is nothing compared to the sun: All the electricity generated on earth is around 3 Terrawatts, while the sun hits us with 200 Pettawatts, 66 thousand times more.

On the other hand, burning fuels releases gasses like CO2, which can traps sunlight and creates thousands of times more heat than the actual amount of power generated. If we stopped burning fuel, it would stop the current massive increase in global temperature, which would then slowly be reversed by things like the carbonate-silicate cycle.

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- humanspiral@lemmy.ca ⁨1⁩ ⁨month⁩ ago
  
  That electricity is converted to heat when it’s used
  
  a missing point is that fossil fuels use 3-4 watts of heat to make 1 watt of electricity or mechanical movement. Electric heat pumps can sometimes make 3-4 watts of useful enough (home) heat from 1 watt of electricity.
  
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- lud@lemm.ee ⁨1⁩ ⁨month⁩ ago
  So lets paint the earth white to increase its albedo instead.
  
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  - Chocrates@lemmy.world ⁨1⁩ ⁨month⁩ ago
    Thats been proposed lol. So many solutions instead of using “use less”.
    
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- Professorozone@lemmy.world ⁨1⁩ ⁨month⁩ ago
  Also large numbers of solar panels like that have other effects, changes in wind patterns and such.
  
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  - Tehdastehdas@lemmy.world ⁨1⁩ ⁨month⁩ ago
    Changes for the better in deserts: farmingdale-observer.com/…/china-confirms-desert-…
    
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  - HeyThisIsntTheYMCA@lemmy.world ⁨1⁩ ⁨month⁩ ago
    I mean I noticed just in small effects the parking lots that have them installed over the parking spaces seem less urban hellscapey to me, by like 5 to 10 degrees hamburger
    
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- vrighter@discuss.tchncs.de ⁨1⁩ ⁨month⁩ ago
  [deleted]
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  - allan@lemmy.blahaj.zone ⁨1⁩ ⁨month⁩ ago
    The work also becomes heat in the end.
    
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  - nothacking@discuss.tchncs.de ⁨1⁩ ⁨month⁩ ago
    That just pushes the heat production down the chain: Take a light: it converts electricity into electromagnetic waves. Those waves the get converted into heat when they hit things.
    
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RandomVideos@programming.dev ⁨1⁩ ⁨month⁩ ago
Technically, if you built enough solar panels in space, they would completely block the sun and massively decrease global temperature

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- finitebanjo@lemmy.world ⁨1⁩ ⁨month⁩ ago
  Yeah, on the earth surface 23% of the light gets absorbed by the atmosphere before it even hits the panel, and 85% of the remained doesn’t get absorbed by the panel at all.
  
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  - mojofrododojo@lemmy.world ⁨1⁩ ⁨month⁩ ago
    perovskites offer tantalizing appearances of being able to take up more, and appear to be coming soon. few bits of good news but that’s one.
    
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  - RandomVideos@programming.dev ⁨1⁩ ⁨month⁩ ago
    Most of the sunlight doesnt even hit Earth
    
    Could you imagine how much more energy we could produce if we used all the empty space in space?
    
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NeoNachtwaechter@lemmy.world ⁨1⁩ ⁨month⁩ ago
Directly, as you phrased the question: No.

Indirectly: Yes. Because we would automatically stop burning fuels when we get all our energy from solar. That would decrease the temerature a tiny little bit.

But the temerature of the planet does not really depend on such actions. For example, the indirect effects of CO2 and Ozone in the atmosphere have much more powerful impacts - and still they can only change the temperature at the planet’s surface. The whole of the planet is yet another thing.

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- olafurp@lemmy.world ⁨1⁩ ⁨month⁩ ago
  Don’t forget industrial heat. If we had infinite electricity for free everywhere there would still be fossil fuels burned for industrial heat. We need more technology to finish it like plasma torches.
  
  No need to despair, the technology is being actively developed and a lot of the sub 600 Celsius temps have an electric solution now.
  
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  - NeoNachtwaechter@lemmy.world ⁨1⁩ ⁨month⁩ ago
    
    Don’t forget industrial heat
    
    Why? Is it different from “all of mankind’s energy”?
    
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  - Tehdastehdas@lemmy.world ⁨1⁩ ⁨month⁩ ago
    
    Industrial electric arc furnace temperatures can reach 1,800 °C (3,300 °F)
    
    en.wikipedia.org/wiki/Electric_arc_furnace
    
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  - ryannathans@aussie.zone ⁨1⁩ ⁨month⁩ ago
    Over 600 might be able to use focused sunlight? Like the tower in the middle of a solar farm? Though seems highly impractical to effectively laser that heat somewhere
    
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vane@lemmy.world ⁨1⁩ ⁨month⁩ ago
Conservation of energy equation says otherwise.

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- finitebanjo@lemmy.world ⁨1⁩ ⁨month⁩ ago
  The nuance here is that the user probably means cooling the earth’s atmosphere, not the earth as a whole enclosed system.
  
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- morphballganon@lemmy.world ⁨1⁩ ⁨month⁩ ago
  Elaborate?
  
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  - noli@lemmy.zip ⁨1⁩ ⁨month⁩ ago
    The assumption here is that solar panels make sure that the energy from the sun gets turned into electricity instead of heat. However, pretty much everything that uses electricity is technically a 100% efficient electrical space heater (eg. A fan turns electricity into heat and kinetic energy… which dissipates into heat). So the only way that solar panels could have a cooling effect is if we didn’t use the electricity (someone smarter than me will probably be able to point out exceptions to this, but still this should be the case for the majority of uses).
    
    Also, since solar panels are intended to capture as much solar energy as possible (hence why they are typically black), the realistic effect of covering the planet with them would probably be a temperature increase
    
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  - vane@lemmy.world ⁨1⁩ ⁨month⁩ ago
    The sum of consumed energy will stay the same, so will be the heat generated by consumption. The only way to efectively decrease temperature is to reduce consumption. www.zo.utexas.edu/courses/…/Global-Warming.htm
    
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Buffalox@lemmy.world ⁨1⁩ ⁨month⁩ ago
Nope, it only helps to not increase it further.

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jjagaimo@sh.itjust.works ⁨1⁩ ⁨month⁩ ago
Assuming 25% efficiency, 25% of the sunlight will be converted into electricity. However, once that energy gets used later, most of it will be converted into heat, one way or another. The main way that it will decrease heat being released into the atmosphere is by replacing less efficient methods of energy generation.

For example, it you normally heat a house with a 90% efficient gas burner to generate 900W of heat on average, you are burning enough gas to generate 1000W of heat on average throughout the day. Lets also say the house gets 4000W of heat across its roof on average throughout the day. Thats 5000W of heat being released into the atmosphere total.

Lets now say you convert to solar panels and now get 25% of that energy from the sun converted to electricity, then into heat in the house. Electric heating is essentially 100% efficient, so you get 3000W of sunlight converted directly to heat in the panels, 1000W of electricity which is also turned into heat in the house = 3900W of heat + 100W of extra electricity (turned into heat elsewhere). The 1000W of gas gets eliminated completely.

It probably wont be anywhere near the numbers listed here and batteries will play a huge role in averaging out these numbers due to varying generation and use throughout the day. Additionally this doesnt account for things like cars and othergas based systems which wont / cant be replaced economically, other technologies like radiative cooling paint, and the fact that global temperatures will likely continue to rise due to the continued release of co2 and other gases. It might slightly slow things down though

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humanspiral@lemmy.ca ⁨1⁩ ⁨month⁩ ago
It would decrease temperatures because no energy emissions brings hope that natural carbon sinks can come close to reducing atmospheric CO2 levels. Hydrogen replacing heat in iron/steel and cement could be enough. But it needs to be quick.

Solar panels provide shade which can cool the ground/water beneath them. At night, they release heat faster than ground, with less of it absorbed by ground relative to air and upwards to higher atmosphere.

google ai does say that more efficient solar panels get less hot. 2-5C over “standard panels”, which I cannot source, but would assume its 2C per 5 %point extra efficiency.
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Brainsploosh@lemmy.world ⁨1⁩ ⁨month⁩ ago
Yes, if the panels were in outer orbit, and mostly powering things outside our planet.

A little simplified energy cannot be destroyed only change form, each time it changes it loses a little bit to energy. Over time that means all energy will become heat.

So the only way to not heat up the earth with energy is to either make sure it doesn’t get to earth, or that we let it out.

Orbital solar cells could keep enough light from reaching earth to cool it, but releasing the energy dirtside would mostly cancel that out. So, we cover the earth orbit with panels and use them to fuel space things.

All of this requires more tech, a lot of resources and time to prepare though. And also a feasible way to store and use that energy in space. Maybe we shoot batteries at a moon base or orbital mining operation?

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- DrunkenPirate@feddit.org ⁨1⁩ ⁨month⁩ ago
  Or just shoot particles into the atmosphere to slightly shade the earth. Happens at every vulcanic eruption
  
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  - MDCCCLV@lemmy.ca ⁨1⁩ ⁨month⁩ ago
    Sulfur cools the planet but not by shading, it’s more similar to how CO2 acts but in reverse.
    
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rayquetzalcoatl@lemmy.world ⁨1⁩ ⁨month⁩ ago
Yes, because if we build enough of them they’ll suck up all the heat from the sun’s rays. However, they would also suck up all the light. And because it would be so dark and cold, people would need their heating and lights on at all times, so the energy consumption actually wouldn’t drop. My chiropractor calls it “The Solar Panel Paradox”.

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- model_tar_gz@lemmy.world ⁨1⁩ ⁨month⁩ ago
  Your Chiropractor sounds like they’re equally credentialed in thermodynamics as they are in medicine.
  
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  - rayquetzalcoatl@lemmy.world ⁨1⁩ ⁨month⁩ ago
    He cricks my neck real good so he must know a thing or two
    
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- finitebanjo@lemmy.world ⁨1⁩ ⁨month⁩ ago
  @sighofannorance
  @rayquetzalcoatl
  Jokes aside, Solar Panels are something like ~15%% efficient, the rest of the light doesn’t get absorbed by the panels. Only ~48% of solar energy gets absorbed by the earth’s surface, ~23% gets absorbed by atmospheric particles, the rest just leaves. So the atmospheric temperatures wouldn’t change much.
  
  If you power Red-Yellow-Blue +ultraviolet LED grow lights for a “full spectrum” effect then you’re still using less power on the lights than the solar panels would absorb.
  
  To reach GHG neutral emissions by 2035 would take adding AT LEAST something like 64 Terawatts of solar. So if a 1MW solar power plant takes up approximately 0.02 sq km (5 acres) then 1,280,000 sq km of solar would do it.
  
  math note: (Somebody needs to check the math on this part because for some reason consumer panels are rated more like 183 watt / sq m which is 3.6 MW for the same size (note that 1 sq km is 1000000 sq m because of the rise in power), just astronomically different than the 1 MW from the big plant…)
  
  Good news, then! We can put the whole damn thing in 1/9th of the Saharan Desert! Or if we trusted that weird consumer number then we can put the whole thing in Montana! That leaves 99.749% of the earth’s surface open to get hit by the sun’s bullshit as nature intended alongside the 78% of the 0.251% that didn’t get absorbed.
  
  Of course, becoming carbon neutral doesn’t offset the methane gasses emitted by the arctic as a result of current levels of warming, and producing more than 67-70 TW of electricity is pointless because we aren’t actually using that much power currently. One potential thing we could try is storing excess power underground such as with molten salt, or storing it on the moon or even as an additional satellite where the material would naturally cool over time.
  
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SocialMediaRefugee@lemmy.world ⁨1⁩ ⁨month⁩ ago
Start reflecting sunlight back into space and increase the earth’s albedo

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- HeyThisIsntTheYMCA@lemmy.world ⁨1⁩ ⁨month⁩ ago
  Wyt urth 4evuh or some nonsense I’m not a scientician
  
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- TriflingToad@sh.itjust.works ⁨1⁩ ⁨month⁩ ago
  but solar panels are black, does that mean it’ll just make the earth hotter overall?
  
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  - rowinxavier@lemmy.world ⁨1⁩ ⁨month⁩ ago
    They appear black because they do not rreflect light but rather than absorb photons as heat they absorb them as electricity. This conversion means they do not get hot like a painted black surface does. In fact, solar panels are heat sensitive and become inefficient if too hot, so some have cooling on the back side or even water cooling.
    
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gandalf_der_12te@discuss.tchncs.de ⁨1⁩ ⁨month⁩ ago
wo:mankind FTFY

but serious answer: no. if humanity sources all its electricity through solar panels, these solar panels would cover <1% (IIRC) of earth’s surface area, so the effect would be negligible.

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jagged_circle@feddit.nl ⁨1⁩ ⁨month⁩ ago
Yes. If we built a giant circle of solar panels in space around the sun, it would cool the earth to the point it would be unlikeable for humans.

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