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NNadir

(33,515 posts)
Tue May 10, 2016, 07:50 PM May 2016

Oh. Oh. Finally a discussion of the toxicology of solar cells is appearing in the scientific...

...literature.

The solar industry, in my view, is useless. World wide, after the "investment of" - I would choose the words "squandered" on - of trillion dollar scale resources for this industry, it does not produce even two of the five hundred sixty exajoules of energy that humanity consumes each year. Moreover, this industry has done nothing, absolutely nothing, to arrest climate change. Despite the massive investment in solar energy, 2015 was the worst year ever recorded for increases in carbon dioxide - dangerous fossil fuel waste - the first year in which these concentrations rose by more than 3 ppm in a single year, 3.05 ppm exactly as recorded at the Mauna Loa carbon dioxide observatory.

2016 is clearly on track to blow 2015 away as the worst year ever observed.

Solar energy is often referred to as "renewable energy," although this too is a joke, since the industry is entirely dependent on access to increasing rare materials, many of which are highly toxic, and which must be mined at great risk to the miners. As I've pointed out many times, one element utilized in the solar industry, cadmium, is now widely found in rice in large stretches of China.

One sees, occasionally, if one takes the time to look, lots of discussion of heavy metal poisoning associated with some of the elements utilized in the solar industry, although seldom is the linkage explicitly made. One must both know the composition of solar materials, the toxicology of the metals involved, and something about their environmental distribution to understand this relationship, at least generally.

Twice a month, as issues are released, I undertake readings in one of the world's most prominent environmental scientific journals, Environmental Science and Technology, a favorite journal of mine.

I was very pleased to read a paper that explicitly refers to the risks associated with solar cells as solar cells.

The paper is here: Bulk Dissolution Rates of Cadmium and Bismuth Tellurides As a Function of pH, Temperature and Dissolved Oxygen

(Environ. Sci. Technol., 2016, 50 (9), pp 4675–4681) (Full access to the paper may require a subscription, payment, or access in a good scientific library.)

Some excerpts from the text:

Tellurium is an extremely rare element in the earth́s crust with an estimated upper continental crust abundance of 0.027 ppm(1) and its distribution and fate in the environmental compartments have been comparatively little studied. There is considerable uncertainty as to its likely concentration in natural waters.(2) Some 123 tellurium bearing phases are known to occur as natural minerals.(3) None of these are abundant enough for economical exploitation. Tellurium, a chalcophile element, also occurs as an impurity in sulfidic copper and nickel ores, thus the element is extracted from mining and refining residues of the copper and nickel industries. It is only over the last two decades that economically significant technological applications of tellurium compounds have emerged. It has recently been identified as one of the key technologically critical elements.(4) Metal tellurides are semiconducting materials, and CdTe is gaining importance as an absorber in thin-film photovoltaic conversion modules, owing to its band gap of 1.49 eV,(5, 6) which exactly coincides with the mean energy of solar light. The principal advantage of CdTe photovoltaic cells lies in the combination of low cost and high conversion efficiency. CdTe is also used in photoconductors, specifically in the manufacture of gamma and IR radiation detectors.(5) ...

...Cadmium is known to be extremely toxic to all forms of life,(11) the toxicity of tellurium is still little understood,(11) even though clear adverse health effects have been known for nearly a century,(12) whereas bismuth—used for more than a century in medicine in the treatment of disorders of the digestive tract and in dermatology(13)—is generally considered as environmentally benign(11, 14) although there are reports of genotoxicity of Bi2O3 nanoparticles,(15) inhibition of growth of soil microorganisms(16) and the neurotoxic potential of some bismuth compounds has been confirmed.(17, 18)

Thin films of CdTe, as they are employed in solar modules, are believed to be environmentally quite safe, because the compound is thermally extremely stable (melting point 1042 °C)(19) and it is sealed within glass plates and contained in between thin layers of other compounds. Fortunately, CdTe can be recycled from used modules in excellent yield.(20) Nevertheless, the rate of release of problematic elements such as cadmium and tellurium from these important industrial materials ought to be known, as accidental release (due to inadequate handling or disposal of the finished products or the compounds themselves) can never be ruled out...


From the conclusion of the paper:

As neither of the two substances showed any signs of passivation during dissolution, one must assume that they would dissolve completely under environmental conditions, but as the measured rates are slow on an absolute scale, the accidental release of these compounds into the natural environment would hardly pose a threat and would in any case leave ample time to be tackled. From this perspective, and given their good thermal stability, it appears that both CdTe and Bi2Te3 are indeed environmentally safe materials. However, both will readily dissolve under long-term deposition conditions such as in landfills or uncontrolled open dumps, with the corresponding complete release of their potentially noxious elements, that is, cadmium and tellurium.


The way I read this conclusion is that the authors find that the solar cells are "safe" for now, but they may have tragic consequences for future generations.

Don't worry, be happy. The way we now conduct our lives shows that it is socially acceptable, completely consistent with our practice in every aspect of our lives, to not give a rat's ass about future generations. The reason we are having children, and grandchildren, and great grandchildren is because we expect them to clean up our mess, and if they can't do that, that's their problem and not ours.

Screw 'em if they can't take a joke.

I'm not really sanguine about the conclusion that "release of these compounds would hardly pose a threat." Other literature shows that they are a threat already, that they are tracked, and nothing, absolutely nothing can be done to remediate exposure to them. Were it possible to remediate these exposures, hundreds of millions of Chinese wouldn't be eating rice laced with cadmium.

Still, the authors failings aside, it's very clear that at least the topic is coming up. Distributed energy, I have long contended, is nothing more than distributed pollution, for the long term at least, and the fact that the solar industry - a failed industry in terms of environmental goals - is still insanely popular is, um, well, insane, and a full measure about how little we care about what we do.

Have a great evening.
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Wilms

(26,795 posts)
1. Reasonable to point out pollution caused by PV manufacture.
Tue May 10, 2016, 08:02 PM
May 2016

But let's bear in mind that China may not be the best at regulating how the mining is done.

And it's not as though uranium mining is without serious problems.

Potential Environmental Effects of Uranium Mining, Processing, and Reclamation

Key Points

• Uranium mining, processing, and reclamation in Virginia have the potential to affect surface water quality and quantity groundwater quality and quantity, soils, air quality, and biota. The impacts of these activities in Virginia would depend on site-specific conditions, the rigor of the monitoring program established to provide early warning of contaminant migration, and the efforts to mitigate and control potential impacts. If uranium mining, processing, and reclamation are designed, constructed, operated, and monitored according to modern international best practices, near- to moderate-term environmental effects specific to uranium mining and processing should be substantially reduced.

• Tailings disposal sites represent significant potential sources of contamination for thousands of years, and the long-term risks remain poorly defined. Although significant improvements have been made in recent years to tailings management practices to isolate mine waste from the environment, limited data exist to confirm the long-term effectiveness of uranium tailings management facilities that have been designed and constructed accord ing to modern best practices.

• Significant potential environmental risks are associated with extreme natural events and failures in management practices. Extreme natural events (e.g., hurricanes, earthquakes, intense rainfall events, drought) have the potential to lead to the release of contaminants if facilities are not designed and constructed to withstand such events, or fail to perform as designed.

• Models and comprehensive site characterization are important for estimating the potential environmental effects associated with a specific uranium mine and processing facility. A thorough site characterization, supplemented by air quality and hydrologi-cal modeling, is essential for estimating the potential environmental impacts of uranium mining and processing under site-specific conditions and mitigation practices.

http://www.nap.edu/read/13266/chapter/9#180

NNadir

(33,515 posts)
4. Uranium mining, however, is not necessary, for several centuries.
Tue May 10, 2016, 08:27 PM
May 2016

Were it not for fear and ignorance, we could completely eliminate the need for all energy mining for several centuries. That would mean no gas fields, no oil fields, no coal mines, fewer lanthanide and cadmium mines.

I went into this topic in detail - with lots of references as opposed to hand waving and selective attention - elsewhere:

Current World Energy Demand, Ethical World Energy Demand, Depleted Uranium and the Centuries to Come

I showed, that at about the twice the continuous average power consumption now utilized by humanity as a whole - not of course the scale of Americans, who are consuming monsters compared to everyone else - that a person living 100 years would consume about 100 grams of plutonium (made from uranium-238) in a lifetime.

I showed that the uranium already mined, along with the thorium waste from refining lanthanides to make useless wind turbines and electric cars, could easily last for centuries when converted into plutonium and uranium-233.

Uranium, which is present to the tune of 4.5 billion tons in the ocean alone, has an extremely high energy/to mass ratio. It is this extremely high ratio, absent in all chemical fuels, that makes it relatively trivial to manage. This mass density is so attractive that it possible to refine uranium from extremely dilute sources, like seawater and the run-off from weathered granite. In fact an entire recent issue, April 20, of the important scientific journal Industrial and Engineering Chemical Research was devoted entirely to this topic:

Industrial and Chemical Engineering Research, Vol 50, Iss. 15, Special Issue, Uranium in Seawater.

It is of some note, that whenever I point out the clear and unambiguous fact that the so called "renewable energy" scheme - which was after all abandoned by humanity at the beginning of the 19th century because the vast majority of human beings lived very short miserable impoverished lives - is a grotesque failure, someone immediately begins spitting horseshit about nuclear energy and its risks.

It has risks, of course, nothing like the risk of dangerous fossil fuels, nothing like the risk of contaminating millions of hectares of Southern China with cadmium, but it has risks.

So what?

People who point out this risks while selectively ignoring all other risks uniformly do not spin any concern about dangerous fossil fuels. Right now, in the primary scientific literature, in one of the references I provide in many of my posts, one can clearly find out that 7 million people die each year from air pollution, about half from dangerous fossil fuel waste, and half from burning "renewable" biomass.

And yet we still have people spewing trivializing nonsense that nuclear energy is "unsafe." Unsafe compared to what exactly? Can all of the people who whine endlessly about nuclear energy show as many deaths from nuclear power plant events as have occurred in the last week from air pollution?

Nuclear energy need not be without risk to be vastly superior to everything else. It need not be perfect to be a vast improvement over everything else. It only needs to be vastly superior to everything else, which it is.

The fear and ignorance associated with nuclear energy is responsible for a loss of life comparable to World War II every decade. There is no technical reason that nuclear energy could not replace all dangerous fossil fuels.

This selective attention is a crime against all future generations as far as I'm concerned, but like I said, I'm rather unique in giving a shit about the future.

Have a wonderful day tomorrow.

hollysmom

(5,946 posts)
2. that is funny, I had attended the view a while ago
Tue May 10, 2016, 08:05 PM
May 2016

and they gave me a free cup (I know, no big deal) s before I gave it away since I have tons of cups, I thought I would research it to see if it was microwavable, turns out it has cadmium in the paint. I put it in a closet - now I don't want to give it to someone and have them get sick. I don't want to trow it away and poison a land fill. what do I do?

See this refers to all the problems there are.
Coal the most poisonous of all fuels, Oil and gas global warming issues, Nuclear - they lie about the cost, the disposal of an old plant is very dangerous and costs multiple times the cost of construction but you will never read that. Wind kills birds/eagles and solar has toxic elements much like fluorescent lighting has poisonous stuff and has to be disposed of carefully. I am sure there are some poisons involves with LED lighting as well. Even Hydro electric has a down side.

I try and lead a regularly economical life, don't buy things jsut because the new ones are better (car is 10 years old and still running fine and economically but still walk places if I can.) Grow old deciduous oak trees to the south, fir trees to the north, protects house from winter wind, shades in the summer. No down side to that.

NNadir

(33,515 posts)
5. I will always push nuclear energy. It's vastly superior to all other options.
Tue May 10, 2016, 08:28 PM
May 2016

I would not be able to live with myself morally if I did not do what I do.

Have a wonderful day tomorrow.

NV Whino

(20,886 posts)
7. Until you can show me
Tue May 10, 2016, 08:55 PM
May 2016

How the waste can be recycled/used down to zero, or disposed of so it doesn't contaminate the earth for millennia, nuclear energy is a nonstarter

NNadir

(33,515 posts)
8. You would need to understand chemistry and physics to get it.
Tue May 10, 2016, 09:21 PM
May 2016

I note that you do not know enough chemistry, apparently, to understand what fossil fuel waste is doing, so it would be a questionable exercise.

As it happens in a high technology society, no one person can understand the workings of every technology. I do read the scientific literature obsessively, and am into my third decade of doing so with a focus on energy and the environment.

I wish that you would be less interested in what you will not start than in trying to stop what you are already doing. You are, if you are living in this country, participating in the vast dumping of wastes that are killing 19,000 people per day, every day, without stop.

In general, I consider the ignorance which demands that one explain everything to people incompetent to understand any of it, or else sit without comment by mindlessly while they engage in actions that kill people now living - and many who are yet not conceived - to be ethically unpalatable.

Nuclear power was invented and designed by some of the finest minds of the twentieth century. A nuclear engineer needs to spent many years developing command of very powerful concepts, materials science, thermodynamics, statistical mechanics, nuclear physics, chemistry etc. Why does anyone who made such an effort have to justify himself or herself to any person too lazy to engage these same concepts?

If you want to know about something, anything, rather than demand that someone give you a soundbite's worth of glib assurance, you could educate yourself.

That's what I did. It works. I used to be a dumb anti-nuke myself, but after thirty years, I finally understand how ignorant I was in those times.

Have a nice day tomorrow.

NV Whino

(20,886 posts)
10. I did not mention coal. Continued use of coal is not an option.
Tue May 10, 2016, 09:34 PM
May 2016

I'm asking for a solution to the longevity of nuclear fuel. So far I've not read of any viable solution.

Surely, with all your studying and superior knowledge, you can provide an answer, just a suggestion. Or, you could just continue to talk down to me and inflate your already considerably inflated ego.

NNadir

(33,515 posts)
11. What do you mean "it's not an option?" It's a REALITY.
Wed May 11, 2016, 06:50 AM
May 2016

If you are operating a computer, you are using electricity. It comes from somewhere, and I assure you that it comes from things that you glibly announce "are not an option."

The problem here is that you have a fantasy, a lazy one at that. Since you have no idea how a solar cell is made, or for that matter a wind turbine I would guess, and have not studied how much money has been thrown at these technologies for no result in terms of climate, you think they are an option. The problem is they haven't worked; they aren't working" and they won't work.

You seem also to think that I have an option about whether or not "to talk down to you." I spent thirty years reading about energy. I am not about to you apologize for being what you call "inflated" on a subject that involved a tremendous amount of work. I'm sorry, but I'm just not in position to kiss people's asses and tell them what you they want to hear, and am only stating what I think everyone needs to hear - if they want to be responsible human beings who care about the world enough to stop repeated cant about so called "renewable energy."

It's a failure. The rate of degradation of the climate is reaching new extremes, right now. It's not an "option." It's what is happening.

Anyone can live in a fantasy world. But reality trumps fantasy.

Have a nice day.



mackdaddy

(1,526 posts)
6. Cadmium telluride photovoltaics are less than 5% of Panels made.
Tue May 10, 2016, 08:38 PM
May 2016

95% of all PV panels are made with silicon wafers, pretty much like all integrated circuit substrates.

All the silicon wafer production whether for IC's or Silicon PV, uses some pretty serious chemicals.

The Cadmium Telluride are a form of what is called "thin film" panels. Many of the thin film panel companies went out of business when the silicon panels dropped by nearly 90% in cost. There were some of these companies in the Toledo area a few years ago. I was at a conference and they were claiming that the amount of CD and TE they were using was minuscule and it was being handled properly and could be recycled when the panels were ultimately melted down. I am not sure if they are still in business.


https://en.wikipedia.org/wiki/Cadmium_telluride_photovoltaics

NNadir

(33,515 posts)
9. The topic of silicon chemistry is another matter, equally as disturbing, I assure you...
Tue May 10, 2016, 09:24 PM
May 2016

...particularly because solar PV energy has an absurdly low energy to mass ratio, making it useless.

I recently attended, in the last two years, a lecture of the subject of cadmium telluride solar cells that went way beyond um, some lazily produced link to a Wikipedia page, and I assure you cadmium solar cells have not, and will not, go away.

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