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Solar panels are photodiode arrays. Photodiodes are made by lacing mid-purity Si with ultra toxic metals. More neurotoxic the better is the basic rule of all hi

Solar panels are photodiode arrays. Photodiodes are made by lacing mid-purity Si with ultra toxic metals. More neurotoxic the better is the basic rule of all high-performance opto-electronics semiconductors. The less toxic you make, the worse they get, and less they responsive to longer wavelength lights. In, Ga, As, P, Si, Zn, Se, Ge, Cd, Te, Pb, etc. The duh materials. Sometimes the whole panel is thin crystals of GaAs. You have to melt that down to recycle.

epistasis 1y ago
Key word here being "lacing." Tractors, trucks, and cars with lead acid batteries are far more dangerous to have out in a field than solar panels. Usually lead used the solder, if there is lead, is the biggest risk!
- numpad0 1y ago
  Those metals are not like Mo additive on greases. The machines that contained those came with warnings long before Prop 65 or EU RoHS simply by toxicity. And deploying PVs is to scale that out into the fields. It's mildly insane thing to do. Even nukes are more eco friendly, even if you include things Fukushima, maybe Chernobyl too. The elephant foot is going to passivate itself before the collapse of human civilization could occur. I don't know same can be said about panels blown away in rainstorms.
DamonHD 1y ago
Show me a field deployment of GaAs! That stuff is so expensive AFAIK that it's almost only for space applications, though things may have moved since I last looked! Most solar is monocrystalline Si with tiny amounts of dopants such as P and B, not especially difficult to deal with. Ag contacts, Al frames, more Si for the glass, and maybe most troublesome the plastic backing sheets and insulants. We just are not spreading heavy metals on our fields.
kragen 1y ago
P isn't a metal, isn't a heavy element, and isn't toxic except in the form of white phosphorus. It's what holds your DNA together and what your mitochondria use to fuel your cellular respiration. Perhaps coincidentally, it's the only element in your list that is used in practice as dopants for silicon solar cells. The other dopant used in practice, which you omitted, is boron, which also isn't especially toxic, and also isn't a metal or a heavy element. GaAs photovoltaic cells, InGaAs photovoltaic cells, etc., do exist, but aren't used in utility-scale solar power, because their cost doesn't compensate for their performance. Some of the other elements you list are never used at all for photovoltaic cells to my knowledge. Wherever you got this information from, you should killfile it and make sure you don't trust any more information from that source.
- pfdietz 1y ago
  Actually, gallium has replaced boron as a dopant for Si PV cells, since it avoids an annoying kind of light-induced efficiency degradation that boron is subject to. I don't believe gallium is significantly toxic, and certainly not at the amounts used as a dopant. The big heavy metal issue for PV has been lead for contact to the backing sheet, but this isn't an issue if you go with bifacial modules (no backing sheet).
  - kragen 1y ago
    I very much appreciate the corrections! Apparently there is one report of gallium poisoning in the medical literature; it was nonfatal but resulted in irreversible cardiomyopathy: https://pubmed.ncbi.nlm.nih.gov/22024274/ https://pubmed.ncbi.nlm.nih.gov/22024274/ https://www.pv-magazine.com/2020/06/13/the-weekend-read-gallium-in-the-fight-against-lid/ https://www.pv-magazine.com/2020/06/13/the-weekend-read-gall... backs you up and also mentions that indium (also nontoxic, as far as anybody knows) has been tried but was not in mass use as of that article. https://www.pv-magazine.com/2022/05/24/gallium-doping-and-solar-cell-degradation/ https://www.pv-magazine.com/2022/05/24/gallium-doping-and-so... talks about the potential of "rejuvenating" gallium-doped PV cells.

epistasis 1y ago

Key word here being "lacing." Tractors, trucks, and cars with lead acid batteries are far more dangerous to have out in a field than solar panels. Usually lead used the solder, if there is lead, is the biggest risk!

numpad0 1y ago
Those metals are not like Mo additive on greases. The machines that contained those came with warnings long before Prop 65 or EU RoHS simply by toxicity. And deploying PVs is to scale that out into the fields. It's mildly insane thing to do. Even nukes are more eco friendly, even if you include things Fukushima, maybe Chernobyl too. The elephant foot is going to passivate itself before the collapse of human civilization could occur. I don't know same can be said about panels blown away in rainstorms.

DamonHD 1y ago

Show me a field deployment of GaAs! That stuff is so expensive AFAIK that it's almost only for space applications, though things may have moved since I last looked! Most solar is monocrystalline Si with tiny amounts of dopants such as P and B, not especially difficult to deal with. Ag contacts, Al frames, more Si for the glass, and maybe most troublesome the plastic backing sheets and insulants. We just are not spreading heavy metals on our fields.

kragen 1y ago

P isn't a metal, isn't a heavy element, and isn't toxic except in the form of white phosphorus. It's what holds your DNA together and what your mitochondria use to fuel your cellular respiration. Perhaps coincidentally, it's the only element in your list that is used in practice as dopants for silicon solar cells. The other dopant used in practice, which you omitted, is boron, which also isn't especially toxic, and also isn't a metal or a heavy element. GaAs photovoltaic cells, InGaAs photovoltaic cells, etc., do exist, but aren't used in utility-scale solar power, because their cost doesn't compensate for their performance. Some of the other elements you list are never used at all for photovoltaic cells to my knowledge. Wherever you got this information from, you should killfile it and make sure you don't trust any more information from that source.

pfdietz 1y ago
Actually, gallium has replaced boron as a dopant for Si PV cells, since it avoids an annoying kind of light-induced efficiency degradation that boron is subject to. I don't believe gallium is significantly toxic, and certainly not at the amounts used as a dopant. The big heavy metal issue for PV has been lead for contact to the backing sheet, but this isn't an issue if you go with bifacial modules (no backing sheet).
- kragen 1y ago
  I very much appreciate the corrections! Apparently there is one report of gallium poisoning in the medical literature; it was nonfatal but resulted in irreversible cardiomyopathy: https://pubmed.ncbi.nlm.nih.gov/22024274/ https://pubmed.ncbi.nlm.nih.gov/22024274/ https://www.pv-magazine.com/2020/06/13/the-weekend-read-gallium-in-the-fight-against-lid/ https://www.pv-magazine.com/2020/06/13/the-weekend-read-gall... backs you up and also mentions that indium (also nontoxic, as far as anybody knows) has been tried but was not in mass use as of that article. https://www.pv-magazine.com/2022/05/24/gallium-doping-and-solar-cell-degradation/ https://www.pv-magazine.com/2022/05/24/gallium-doping-and-so... talks about the potential of "rejuvenating" gallium-doped PV cells.