Zombie, of San Francisco’s “Zombietime” fame, writes in with a question that he has graciously allowed to be given to our readers.
He writes:
I’m preparing to write an essay on the following hypothesis:
Solar power installations, especially in desert areas, replace light-colored high-albedo sand/rock ground surface with very low albedo black solar panels. The “side effect” (in fact, the whole purpose) of solar panels is therefore to capture radiant energy coming from the sun that would otherwise reflect back into space. Because this energy is then converted into electricity, which is then used to power devices and inevitably degrade into atmospheric heat (which does NOT as easily radiate back out into space), the overall result of large solar panel installations is to heat up the planet more than it would be heated without the solar installations.
But of course the solar-energy advocates will say that the solar installation is replacing a carbon-burning power plant, which produces greenhouse gases that the solar facility does not.
The question I seek to answer is:
Has anybody ever actually sat down and calculated whether the CO2 greenhouse effect caused by a carbon-based power plant generating one megawatt of electricity is more or less than the warming effect caused by the lowering of the earth’s surface albedo from a black-panel solar installation with power output large enough to completely replace the carbon-burning power plant?
I suspect that no calculations of this type have ever actually been done, and that solar panels may in fact contribute more to global warming than anyone previously realized — and in fact may cause just as much warming as the power sources they replace.
I have searched but cannot find such a study; but the reason I’m writing to you is that I have some vague memory of this thesis once being discussed on WattsUpWithThat — although I no longer can track down where exactly.
So I ask: Do YOU (without any time investment) remember offhand where or when this hypothesis was discussed on WattsUpWithThat? And if not, do you think this is a worthy line of investigation?
I know this is a somewhat vague question, but your guidance is invaluable!
— zombie
So many lizards and other little desert creatures will die because they cannot get enough sun, but that is accounted for by all the birds that would have eaten them will be dead as well, because the wind beaters will swipe them from the sky. It will all be worth it, though, because all those nasty rattlesnakes will be dead. Good riddance to them!
@David, UK
The point is that if we replace a Coal Power Station with Solar Panels then what is the net temperature change caused by the two factors:
1) The presumed decrease in global temperature due to the reduction in CO2 emitted;
2) The presumed increase in global temperature due to the energy absorbed by the solar panels which would otherwise have reflected back into space.
Whilst there are an infinitesimal number of panels today, the assumption has always been that by replacing Coal Stations with Solar Panels would reduce the planetary temperature because only the first factor had been considered. This post is asking the question: How big is the second factor compared to the first factor.
Replacing a 1 gigawatt electric coal power plant would take a solar photovoltaic array of about 10 million square meters of arid land surface of 0.4 albedo in the SW USA.
The solar energy absorbed above land surface would increase by about 6 gigawatts average over a year. The coal plant also dumps about 2 gigawatts of waste heat for a total of 3 gigawatts of net heat since all electricity ends up as thermal heat.
Therefore, any photovoltaic energy used to displace coal generated energy about doubles the net heating to the planet. In both cases the amount is negligible to global temps.
Surface energy data have already been measured and are available from the National Renewable Energy Lab (NREL) for land based flat surface plates.
Note that surface albedo over tropical ocean would be INcreased by photovoltaic arrays.
There’s no need to think about the effect of solar panels on global warming because there’s simply not enough available silver to make enough solar panels to ever make a difference.
Another question I’d like answered is, “How efficient is current solar tech compared to photo synthesis?”
The reason, I’m wondering if perhaps the future of solar is going to be a hybrid of genetically engineered plant material, bacterial material, and nano-tech. I imagine dynamic systems which produce energy through photo-synthesis and immediately convert this to electricity, or depending on demand, into liquid fuel.
In response to Wayne, here is my simple column density calculation: Venus has 96% CO2 x 90 bar pressure and Earth has 0.04% CO2 and 1 bar, thus Venus’s column density of CO2 is 90×96/0.04=216,000 times that of Earth. This is 17.72 doublings of CO2. In my previous posting I calculated 97C of warming due to Venus’s atmosphere, thus this shows 97/17.72 = 5.5C of warming per doubling of CO2. Uh oh, isn’t that Trenberth’s figure? I uphold my calculation but disavow the results. 🙂
Curt posts similar numbers, except he uses a 1 megawatt reference.
The basic idea remains that at photovoltaic power plant produces twice as much thermal energy as a coal fired (or nuclear) plant. Coal plant CO2 emissions have no measurable thermal effects on land temperatures. Fossil fuel emissions add about 3 percent to the natural global biogeochemical Carbon cycle. Natural variations in biological surface albedo are much larger.
Roy Spencer did a pretty interesting study on heat released by resistance losses associated with electricity being used, if I recall. Eventually the electricity that does work will end up as heat if I recall correctly.
Here is another known fact that will provide us with free energy once constructed. One thing I see is we could use personal exersize equipment to generate powerI don’t know if you ever pegged a card to your frame which made contact with the spokes and mad a motor sound. Well replace the card with piezoelectric material and charge up home batteries. Jim stop running around the room screaming HE’S DOING IT AGAIN This would help kill [two] birds with the one stone by giving people a reason to exersize and fight the obesity problem you would be saving money every Km you peddel Or we could conect a piezoelectric device to that whirley bird that sucks hot air from the inside of our roof space http://en.wikipedia.org/wiki/Piezoelectricity
Most people like Merry-Go-Rounds.
So the question is: “Are Man-made efforts to prevent Global Warming causing Man-made Global Warming?”
There’s certainly a lot of intelligent and thoughtful people posting on this topic. . . but please try to get out of the weeds as you think about the energy balance. The more energy we capture via solar or even wind, the less is transmitted (reflected) back to space! Remember most, if not all, of the captured solar and wind energy is ultimately dissipated at heat! Maybe I’m wrong, but this seems simple and only gets confused by all the uncertain discussions of heat losses, efficiencies of all the subcomponents and processes etc. . Let’s put it another way. . . if a fraction of solar radiation, normally reflected back to space, is instead retained/absorbed, in part, by a solar collector, the wind, and other downstream processes, is not the outgoing heat loss reduced, thereby increasing the global heat retention? I’m simple minded so correct me if I’m wrong.
My point is that the AGW solutions seem both juvenile and futile?
Dan
EWF, it has to do more with the same properties of any atmosphere as to why you can look directly at the sun without harm as the sun nears the horizon. The solar radiation which our atmosphere is ‘transparent’ is reduced to 1/30th it’s zenith power. You seem to be treating co2 as unique. Now that is shortwave but do you not see the same occurs with longwave in any mixture of gases, a complete spectrum of all frequencies involved? You look only at co2, I try to stay away from such mis-assumptions and I feel it is better dealing all gases as a whole. I believe the topics are more found under air mass, atmospheric mass attenuation, optical path length when comparing two different atmosphere compositions than IPCC’s story-line.
eco-geek alluded to this, but solar arrays convert much of the incident solar radiation directly into heat. For silicon cells, all radiation absorbed above 1.1 microns wavelength is converted directly to heat, and a substantial portion of the absorbed radiation below 1.1 microns (including the visible) is also converted to heat, due to the limited quantum efficiency of the conversion (electrons out / photons in).
DanMet’al says:
December 10, 2013 at 4:43 pm
My point is that the AGW solutions seem both juvenile and futile?
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Don’t forget counter productive and excessively expensive.
I find this to be an interesting question, and I have previously raised the point that solar panels trap heat on the earth that would not happen if the Solar Panels did not exist. It is simple thermodynamics, the sun’s rays are converted to electricity which ultimately becomes heat that is released mostly at another location and only a portion of which is radiated back into outer space. Advocates of solar panels either do not understand this or dismiss it as trivial. There is a net heating. Of course burning fossil fuels similarly releases heat into the earths system a portion of which is radiated into outer space even if CO2 contribution is nil. Others are more qualified than I am to calculate the relative effect of solar panels versus conventional fuels.
I accept the theory that solar panel impact is presently trivial, but one needs to address the proposals for significantly more solar energy being brought into the earth via solar collectors in various forms including the following:
http://www.foxnews.com/tech/2013/11/29/japanese-firm-proposes-building-solar-panel-ring-around-moon/
Note that none of these advocates address the issue raised by this post since they are obsessed with the theoretical impact of CO2 and ignore the downside of the alternatives. We need to do the calculations accurately to understand the issue.
While planned obsolecence is being used as the primary driver of western econamies we will never look outside the box http://www.youtube.com/watch?v=24fJn7jzGSE I wounder were Jim stands on this
Wayne, what you say is true but the way to do any physical calculation is to first quantify the primary component and then quantify the perturbations. I kept it simple to use CO2 (the primary component) only. Presuming my calculation is accurate, then it’s a big ask to perturb well away from the primary outcome.
DonV says:
December 10, 2013 at 3:34 pm
Thanks, Don. My calcs are above for those who missed them.
In my analysis, I assumed that whatever energy wasn’t reflected was either turned into electricity and eventually into heat, or turned directly into heat. I estimated total heat by calculating the increase in absorbed energy due to increased albedo.
Since I’ve included all of the captured energy, I don’t think that your issues of various emissivities and absorptivities come into play.
All the best,
w.
Michael Gersh says:
December 10, 2013 at 4:04 pm
“… all those nasty rattlesnakes will be dead. Good riddance to them!”
________________________________
I can agree with parts of your light- hearted words, but don’t know where you got the idea that Rattlers are nasty or don’t have a place. They will not kill a small animal if they are not hungry. I have watched them be pestered by mice, which will eat the dead skin off their hides and eat their rattles and the mouse will have his way with the snake if he’s not hungry. Plenty of snake species will kill when not hungry- almost all the constrictors come to mind.
Rattlers are very social and gather in enclaves in caves and dance with each other, etc.
You can even dance with a rattler, but they won’t be treated disrespectfully.
Rattlers will tell you to back off before they whack you, what more could you ask of them.
Ps I’m no herpetologist
On our boat, we have mounted the solar panels with a six inch air space between the panel and the cabin top, to prevent the heat absorbed by the panels from mechanically transferring into the boat. The tropical breezes blow through the space and whisk away the heat. The panels, in the tropical sun, get hotter’n a pistol.
So many stupid answers and people but we have a winner
Who correctly identified that a solar panel will always rate lower than coal or any fossil fuel burning because the CO2 effect is cumulative.
Repeating I am not a climate scientists so I am not saying what is wrong or right here just identifying the facts. This area was one thing that was tightened up by the IPPC 5th assessment and if you really are interested it is worth reading at least reading it before making further stupid comments.
For those of you too lazy and/or stupid to bother reading the IPCC report the old version appears in Wikipedia (http://en.wikipedia.org/wiki/Greenhouse_gas) and it comes under the heading global warming potential (GWP) timescales and life cycles
CO2 is defined as 1 on all timescales … AKA all effects are cumulative … they never diminish.
So with all that plugged in go further down the Wikipedia page and you will find “Lifecycle greenhouse gas emissions by electricity source” and it gives you the answer
Solar PV 46 gCO2/KWh
Coal 1001 gCO2/KWh
So there is the answer for Zombie as given by climate science and it wasn’t that hard to find … you just have to read.
As I said the IPCC 5th assessment actually changed a fair bit of this it is actually quite different from IPCC 4 but just hasn’t got media time except really in the oil and gas industry itself.
http://blogs.shell.com/climatechange/2013/10/ipccrelease/
DanMet’al says:
December 10, 2013 at 4:43 pm
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It all gets radiated back to space, eventually. The amount of energy “delayed” by the panels (and downstream equipment powered by the panels) is almost immeasurably small in comparison to Earth’s daily energy budget. Local effect is lost in the grand scheme and ends up not rising to the effect of a pixel in the big picture.
LdB says:
December 10, 2013 at 5:43 pm
“So many stupid answers and people…”
“For those of you too lazy and/or stupid to bother reading…
Solar PV 46 gCO2/KWh
Coal 1001 gCO2/KWh
So there is the answer for Zombie as given by climate science and it wasn’t that hard to find … you just have to read.”
___________________________
Pardon, but you answered a question which Zombie didn’t ask, all the while calling people here lazy and stupid.
Ja Ja Ja Ja
Oh, by the way, since you were so quick to agree with Curt, but apparently didn’t read or comprehend what he said, here’s the money quote for you:
Curt says:
December 10, 2013 at 3:52 pm
“Close analysis of real electrical grids indicates that heavy use of renewables may not be reducing CO2 emissions at all due to the need for lower-efficiency backup.”
In theory everything is supposed to be in the lifecycle number in the IPCC 5th data. The energy to make it, dispose of it after it dies and the life cycle losses such as transmission. Again read the report it’s all explained so that argument doesn’t wash.
The problem for me is it all comes down to averages, average losses , average this, average that and when you take a specific site the number may be wildly differently. That is one of the weakness points about the approach is in certain sites you might get better results not doing the normal but climate science doesn’t allow that approach.
I am not here to defend climate science I am just saying how it works in the framework they have created and all energy comes back to a CO2/KWH number over the lifecycle of the supply.
Can I say what I think is the real issue an I really doubt that CO2 has a value of 1 over all lifespans do some reading on CO2 turnover. I think this is one of those political things because if it had a lifespan USA and Europe would be off the hook for past emissions and would not be expected to pay for past emissions. If any climate scientists are kicking around I would love to hear your argument of a value of 1 on hundred and 1000 year numbers.
@EWF
As far as what the temp would be on Earth if the atmosphere was 100% CO2, I suspect we’d be living on Mars and using satellites to take the measurements.