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
Willis Eschenbach says:
December 10, 2013 at 1:26 pm
. . .
0.0008 = W/m2 at 3.7 watts/doubling CO2
Doesn’t this term accumulate year after year? More properly, the accounting would have CO2 forcing accumulating at this rate and depreciating at the effective lifetime of atmospheric CO2.
Zombie, one should also do an audit of the CO2 and energy expended in producing the materials and installation of the panels. Glass furnaces have to heat the charge of silica sand, feldspar, etc (which has to be mined and processed) up to >1500C … etc..
Turning bright-white desert regions dark with costly, inefficient, disfiguring arrays of solar panels, then pejoratively calling such blighted acreage “black”, is a profoundly racist approach to making Gaia’s quietus with klimat kultists’ “bare bodkin.” We of the Green Gang know Thought Crime when we see it… off to ye killing fields you go.
Isn’t the simplest answer to this that whatever the original energy source (sun vs. chemical energy stored in fossil fuels), ultimately what we are doing is converting it into electricity which then, as Zombie says, “inevitably degrade[s] into atmospheric heat”. So yes, with solar energy we are adding heat to the atmosphere that otherwise would not be there but the same is true with fossil fuels. In the case of fossil fuels we are adding heat to the atmosphere that would otherwise have stayed trapped in those chemical bonds. So it seems to me, at least with regards to residual heat that gets added to the atmosphere as the electricity degrades back to heat, that it’s a wash. That happens no matter what so should not even be considered.
Next question would be to consider how efficient each method is. A coal fired power plant I’m sure does not convert all of the heat from burning into electricity. So besides the heat that you get from the electricity it generates eventually degrading back into heat, you get a lot of waste heat that goes directly into the atmosphere when it burns.
The only analogous thing I can think of with solar panels is that maybe they’re not 100% efficient either. And maybe, because solar panels are dark, that wasted energy is turned into excess heat that would normally have been radiated back into space because the ground is typically more reflective than a solar panel. Is that more than the waste heat from a typical coal-fueled power plant? I don’t know but my gut tells me no.
But no matter what, one thing that solar has over fossil fuels is that there is no CO2 produced as a by-product (unless you consider CO2 produced during their manufacturing, but I don’t really think that was the point of the original question). I’m an AGW skeptic, so I’m not convinced this is a bad thing (or as bad as alarmists would have us believe) but it seems to me if you’re trying to convince a true believer using this argument, it’s not going to fly. If one accepts the premise that CO2 is bad and is raising the temperature of the earth, the argument that solar adds more heat to the atmosphere than fossil fuels doesn’t make sense.
Why talk about PVs? Solar thermal is a better plan for electricity production.
This is reminiscent of a climate impact analysis on wind farms I recall. The numbers were quite staggering. (Actual paper embedded in the article)
http://web.mit.edu/newsoffice/2010/climate-wind-0312.html
The same holds true with the environmental impact of hydroelectric power above and below a dam.
I just wonder the total acreage required to replace 10% of the total global electrical output in today’s terms with the current and best solar solutions.
Would the earth look like an 8 ball at the 50% replacement level?
Lots of good food for thought in this thread. Thanks for that to everyone!
Zombie,
Ya never know when a Apache with tfk war paint on will be behind a hot rock in Az. or New Mexico looking for some good horses to steal and re-sell. Great great, great grand dad’s way was to get to a heard of U.S. Army horses and steal some 40 or 50 of them.
About a week later one of his other brothers would show up with some horses stolen from over in Texas and sell them to the U.S. Army.
The ones from New Mexico would be driven over to Ft. Sill in Ok. and sold.
You have to watch out all the time for tfk types.
So, how much of the electricity made out in the desert by solar panels gets to the meters and used after pushing its way down 300 or 600 miles of transmission/distribution/transformer wires to a toaster in Lost Wages? There be resistance some say.
That and the problem of the power factor thingy.
Useless as breast on bore hogs some say.
Stunning question really. Wish I thought of it….
I know photo voltaic panels are very inefficient regarding the width of the band of absorption. So what happens to the rest of the heat?
Reflected, absorbed and re-emitted as heat.
Seems to me that this is easy to calculate and may have already been done. I wager that photo-voltaic panels are in fact a worse planet warmer than a coal fired plant, net KW for net KW. This is within my competence to broadly model and calculate but I am a bit busy. Has anyone else done this?
Any takers?
The “global” effect of such solar-arrays is negligible. What is worrying is the immediate local effect — it would prb’ly cause local extirpation of wildlife. Why aren’t the greenies worried about poor desert tortoises?
Robertvd says: What would Earth’s surface temperature be in a 100% CO2 atmosphere ?
It would not be much different from what it is now.
Venus has 93 times as much atmosphere as Earth, many probes have been to Venus and allowing for the difference in distance from the Sun, at the point in Venus’s atmosphere the temperature is essentially the same as on Earth.
http://theendofthemystery.blogspot.co.uk/2010/11/venus-no-greenhouse-effect.html
Is exhaled CO2 reduced by the slaughter of big birds of prey or does the resulting increase in rodent populations more than make up for it?
An equally important question is … “what is the difference in CO2 output between a typical gas-fired generating station and a typical solar panel array plus gas-fired backup”? Is it 50%, 25%, 10% less? Then look at the CO2 cost of constructing and maintaining the solar panel array. Is it 5%, 10%, 25% equivalent to a gas-fired plant?
We had a gas-fired plant recently installed about 20 km from our home, presumably as standby power for solar and wind and to replace coal-fired stations that were killing “tens of thousands each year”. The cost of this plant was several hundred million. The government cancelled two similar plants (because residents didn’t want a gas-fired generating station in their backyard) at a cost of $600 – $1,100 million (the figures vary depending on who in the government is giving the answers). Plus we now generate excess electricity that we sell out of province at a loss. All the while our electricity rates are $0.16 / kWh, up over 50% from less than 10 years ago.
I guess my point is net/loss CO2 calculations are meaningless when the cost of such is not factored in. Cost is CO2 as well.
Whew, I knew I’d forgotten something in my Venusian calculation of CO2 forcing because in no way is Trenberth’s figure of 5.5C right. Now I realise I left out the albedo. Doh. The correct albedo to use is the “bond albedo” from de Pater & Lissauer, Planetary Sciences 2001 which gives 0.29 for Earth and 0.75 for Venus. So 5.5C x 0.29 / 0.75 = 2.1C per doubling of CO2. There, that’s better! My apologies for this oversight, especially to Wayne, wherever you are.
Whoops, the albedo goes the other way. OK, I abandon the battlefield, this battlefield anyway. Apologies for not having presented a comprehensive accounting.
4 eyes says:
December 10, 2013 at 11:49 pm
My calcs re waste heat:
…
= 0.0419 degK per year
= 0.419 degK per decade
= 4.19 degK per century
…
Either way there is a serious negative mechanism.
—
Hold on. That is a classic “climate science” mistake. You cannot extrapolate that value accumulatively into the future, for the minute the Earth was about 0.01°C warmer, maybe 0.02°C all of humanity’s energy output would then be radiating to space, no accumulation occurring. End of story of humanity’s energy use raising Earth’s temperature at +0.01°C.
Now if a century from now every human is consuming some 600 times more energy each second than today your 4.19 degK then may come to be true or so my calcs show.
To me it is still not clear why we should install photo voltaic panels in the desert to lower atmospheric CO2 if it is not clear what influence CO2 has on temperature. Photovoltaic is great to heat my warmwater reservoir to lower my energy costs. I could understand that burning coal or gas or oil is bad because of the fact that it destroys O2 what would have a huge impact on live on earth. But more CO2 would also support more plant life producing O2. So why solar panels if a coal power plant is much more efficient and use the money we safe for affordable health care and investments to rebuild the production industry and to eliminate poverty.
We need to remember to include a calculation for the value of shade for the tortoises
Relevant and on point, thanks.
But it mis-conceives the issue, I believe. Here’s a quote: at night the modules cool to temperatures below ambient; an example is shown in Fig. 9. Thus, this PV
solar farm did not induce a day-after-day increase in ambient temperature, and therefore, adverse micro-climate changes from a potential PV plant are not a concern.
The cooling is a transfer of heat energy either to air or space. The ambient night temperature in the local area is likely to be higher than in the absence of the panels.
just want to take this opp. to say thank you, Zombie. Your website is as illuminating within its sphere of interest as WUWT is in its sphere.
In particular, I was completely unaware of how much lewdness and public indecency occurs at some of the events you cover.
DrTorch says:
December 11, 2013 at 7:56 am
Why talk about PVs? Solar thermal is a better plan for electricity production.
Solar thermal does not exist in AGW – which has no direct downwelling of thermal from the Sun.
Back to the OP’s question; “it depends”.
For instance number 1:
What is done with the resulting electricity? If it is used in an endothermic reaction then the energy can be “locked up” in the product being produced. For instance “polymerisation” (eg making plastics) is an endothermic reaction that takes heat from its surroundings. Similarly cooking most foods (frying an egg, baking bread) are also endothermic. However, in those cases, the body eating the bread will convert most of the energy absorbed back into heat. Plastics, however, will probably almost never release the energy absorbed back into the environment.
For instance number 2.
What is the albedo of the surface being covered? Most solar panels in the world are not in deserts – which are actually a particularly hostile place to stick them. Most, such as in Germany and the UK, are put on open fields where grass would otherwise be. Grass is, of course, also absorbs sunlight and turns it into useful energy for cows and sheep and has a relatively low albedo.
I suspect the actual answer is that the effect is vanishingly small. Probably not unlike the greenhouse effect from the extra CO2 from fossil fuels. Not so much a zero sum game, more a sum of zeros game!
Many people just assume Zombie is a ‘he’. After reading many, many articles by this person, I am convinced she is a ‘she’. FWIW.
@ur momisugly Shooper 5:41 am
Zombie’s gender is his/her business. “Those that tell, do not know, those that know, do not tell.”
@lowercasefred
Yeah. I wasn’t making a case. Just sayin’. For What It’s Worth., Information, ya know.