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The topic is whether solar panels contribute to global warming, not whether global warming is a real phenomenon, and the physics involved proves that the answer to the question asked is no, as several posters have pointed out in various ways.
No, this question is simply not true as stated. It's based on a misunderstanding of the fundamental laws of physics. Solar panels do not attract heat, either to earth or to themselves. Sunlight falls uniformly on earth in a more or less constant rate, whether it falls on land, water, mountains, valleys, snow, solar panels, or tinfoil hats.
Well...
Some of the sunlight is converted to electricity (10-15%), some of the energy is converted to heat. There are a few things to consider when providing a definitive answer, concepts like insolation, albedo etc.
There is also this to consider: solar panel will create electricity, thus offsetting the electricity produce by "dirty means" such as coal. Ask yourself this: how much heat/waste is produced when burning coal and how much of this is offset by solar panels. Also, there are trucks, machines burning fuel etc. involved in electricity production using non-renewable sources. These too release heat and gases. This is something to consider in the "equation".
Overall, my answer is no, solar panels do not contribute to heat islands or overall temperature rises. I am comfortable with understanding why that is the case. However, seems to me the OP came here asking the question but being prejudiced in the answer he/she was expecting.
At least once a week I hear the term "global warming" from the media. No one seem to have a definite clue on what may be causing it or if its a fact at all. Some people think it can be controlled by stopping the amount of carbon emissions...etc. Some think solar panels is one tool that can help solve the carbon emission problem. Questioning with an inexperienced non-scientific mind, if global warming really exist, can more solar panels be a contributor to it? Solar Panels are designed to collect/attract the sun rays and turn them into energy. Like a magnet drawing in not only rays but heat also. With enough solar panels scattered everywhere on the planet, that's a lot of heat being drawn to the planet that wasn't being drawn in before the creation of solar panels. The reason for this question, I think back as a kid with a magnifying glass in hand me an my friends used to set things on fire using the magnifying glass to collect the suns power/rays. With this in mind, I think of some solar panel farms in different locations and some that you can't get close to, because of the heat being generated. And I never heard of a "heat test" being done on the area around these solar panel farms, a test of the amount of heat being drawn in or a theory/test of the cumulative compounding affect of heat/rays being collected by so many solar panels.Anyone with a clue please chime in!
Solar panels only make use of the sunlight that is already falling on them. Without the solar panels that sunlight would fall on the ground or on the grass. Solar panels do not attract heat that is not already there.
I played around with a magnifying glass myself when I was a kid. You may have noticed there was something of a shaddow around the bright spot you were heating up with the magnifying glass. The maganifying glass was not attracting sunlight that was not already there, either; it was only concentrating the sunlight from a couple of inches around so that most of it fell on one spot and this left a darker area where that sunlight would otherwise have fallen. Something similar happens with a parabolic mirror.
Solar panels only make use of the sunlight that is already falling on them. Without the solar panels that sunlight would fall on the ground or on the grass. Solar panels do not attract heat that is not already there.
Not correct, some of the light (30%) hitting the earth will be reflected back to the universe. Solar panels have a much higher absorption coeficient, hence they do increase the temperature. Tha same arguments is used for melting polar caps which also increase the temperature.
However, the actual increase in earth temperature from solar panels is tiny.
Not correct, some of the light (30%) hitting the earth will be reflected back to the universe. Solar panels have a much higher absorption coeficient, hence they do increase the temperature. Tha same arguments is used for melting polar caps which also increase the temperature.
However, the actual increase in earth temperature from solar panels is tiny.
Actually it is significantly more complex than your assertion. In the immediate area solar panels cool because they convert solar energy to electrical energy which is transported elsewhere. When that electrical energy is used to perform work or create light, the energy is released to the environment again. The net heating or cooling is probably too complex to assess. What isn't too complex is that the solar generated electricity displaces fossil generated electricity and that has a large net carbon savings.
So overall PV cools locally and globally.
It is important not to treat these questions simplistically.
Solar Panels are designed to collect/attract the sun rays and turn them into energy. Like a magnet drawing in not only rays but heat also.
Quote:
Originally Posted by Camlon
Not correct, some of the light (30%) hitting the earth will be reflected back to the universe. Solar panels have a much higher absorption coeficient, hence they do increase the temperature.
Quote:
Originally Posted by DCforever
Actually it is significantly more complex than your assertion. In the immediate area solar panels cool because they convert solar energy to electrical energy which is transported elsewhere. When that electrical energy is used to perform work or create light, the energy is released to the environment again. The net heating or cooling is probably too complex to assess. What isn't too complex is that the solar generated electricity displaces fossil generated electricity and that has a large net carbon savings.
Oy!
This is rapidly turning into something akin to a debate about how many angels can dance on the head of a pin.
What I find most significant here is that the original question posed was fallacious to begin with. Solar panels don't attract heat or light like a magnet. Nothing attracts heat or light in the sense that the OP meant it. Light travels in a straight line from its source until it is absorbed or reflected from the surface it falls upon. Actually, make that "absorbed AND reflected" since no material does either perfectly. Put a mirror out in direct sunlight and it will reflect most of the light away, but it will also get hot from the tiny fraction it absorbs.
The amount of light reflected or not reflected from a solar panel compared to the earth or water or ice underneath that it shadows is inconsequential, as is the amount it absorbs. All of that energy from the sunlight, whether directly or indirectly, having done work or not, winds up being radiated out to space, sooner or later. The catch is, not all of it escapes. Some is reflected back by the "greenhouse gases" and small particles in the atmosphere. When not enough is radiated back to maintain heat stasis, than the planet cools. When too much is radiated back, then the planet heats up. When it's just right, the temperature remains the same.
Although the various mechanisms through which this occurs are complex and diverse, the overall effect is just this simple. We're like Goldilocks... we don't want the world to be too hot, and we don't want it to be too cold, we want it to be just right. Regulating the amount of greenhouse gases like CO2 and methane in the atmosphere that trap outbound heat radiation is the primary thermostatic control we have. And solar panels help us gain control of that critical mechanism by generating electricity without releasing those emissions.
"For the solar industry, the Stanford team found that more work is needed to make grid-scale storage energetically sustainable. The study revealed that some solar technologies, such as single-crystal silicon cells, are growing so fast that they are net energy sinks – that is, they consume more power than they give back to the electrical grid. From an energetic standpoint, these industries "cannot support any level of storage," the study concluded.
"Our analysis showed that, from an energetic perspective, most photovoltaic technologies can only afford up to 24 hours of storage with an equal mix of battery and pumped hydropower," Dale said. "This suggests that solar photovoltaic systems could be deployed with enough storage to supply electricity at night, and the industry could still operate at a net energy surplus."
One advantage of wind over solar power is that it has an enormous energy return on investment, Benson explained. "Within a few months, a wind turbine generates enough electricity to pay back all of the energy it took to build it," she said. "But some photovoltaics have an energy payback time of almost two years. To sustainably support grid-scale storage will require continued reductions in the amount of fossil fuel used to manufacture photovoltaic cells.""
Some of the sunlight is converted to electricity (10-15%), some of the energy is converted to heat. There are a few things to consider when providing a definitive answer, concepts like insolation, albedo etc.
There is also this to consider: solar panel will create electricity, thus offsetting the electricity produce by "dirty means" such as coal. Ask yourself this: how much heat/waste is produced when burning coal and how much of this is offset by solar panels. Also, there are trucks, machines burning fuel etc. involved in electricity production using non-renewable sources. These too release heat and gases. This is something to consider in the "equation".
Overall, my answer is no, solar panels do not contribute to heat islands or overall temperature rises. I am comfortable with understanding why that is the case. However, seems to me the OP came here asking the question but being prejudiced in the answer he/she was expecting.
You are correct. The major issue is what generation technology is displaced and emissions avoided.
I did an online search and came across an article yesterday about how to measure heat generation of solar panels. It seem I'm not the only "child" with this curiosity. And I never claimed to be knowledgeable or scientific in the area. So my original question does stand. So far there has been no meaningful study/testing done.
I did an online search and came across an article yesterday about how to measure heat generation of solar panels. It seem I'm not the only "child" with this curiosity. And I never claimed to be knowledgeable or scientific in the area. So my original question does stand. So far there has been no meaningful study/testing done.
As I and other s have pointed out your assessment is simplistic and conclusions are wrong. PV reduces global warming.
If you think sun rays don't generate heat or produce heat. Spend some time in the attic underneath the roof of your home, one summer day. You won't be in your attic for long unless you like an extreme dry sauna.
Last edited by rmaster; 07-28-2014 at 06:02 PM..
Reason: typo correction
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