5 ms·

Agrivoltaics seems like a cool idea but one of the things I rarely ever see mentioned is how chemicals from the panels interact with the crops. Steel can rust a

by lpapez 3y ago

Agrivoltaics seems like a cool idea but one of the things I rarely ever see mentioned is how chemicals from the panels interact with the crops. Steel can rust and if rust gets washed away into the earth and then the plants... well that cant be beneficial right? And I bet steel is the least toxic element of the panels.

hosh 3y ago
There are plants that can do soil remediation on soil with heavy metals, though you can’t eat them and you still have to find a way to process or sequester the heavy metal. Cilantro (coriander) is an example.
kibwen 3y ago
Iron is often used as a fertilizer, so rusted support beams aren't a problem, either for the plants or for humans. And all the interesting parts of a solar panel are under glass, they aren't being washed away by rain.
hannob 3y ago
Rust is just iron oxide, which in small quantities is a relatively benign substance. And probably there's more rust coming from old farming equipment than from the (likely high quality, because they are built for expensive solar panels) steel structures here. The solar cells themselve are mostly made out of silicon, which also isn't a dangerous substance. I don't think this is an issue.
sigstoat 3y ago
the solar facilities i'm familiar with use aluminum beams for the structure. it is more than strong enough, lighter so it is easier to install/ship to site, and requires no special treatment to survive the environment for more than the life of the installation. the panels themselves do not contain steel, either. > And I bet steel is the least toxic element of the panels. perhaps, but nothing on the panels comes off. they're solid objects largely impervious to all forms of precipitation. more of your house washes away in a storm than comes off a panel.
tuatoru 3y ago
Steel structural members used outdoors are coated, normally with zinc (called galvanizing). You see rust when the galvanizing has been corroded through. Sometimes a zinc + aluminum alloy is used as it lasts longer than pure zinc. You should be more worried about those elements washing into the soil. But it turns out that zinc is an essential micronutrient (as is iron) and aluminum is a large part of clay soils anyway. Other components of solar modules, roughly in order of mass:- - Glass. This is heavily purified and baked soil. Not a problem. - Silicon. This is the reduced metallic form of dirt, the equivalent of steel compared to rust or iron ore. Rusted silicon is all around anyway. - Aluminum wires and connectors. Already covered. - Plastics used to insulate wiring. Here we might have a problem, with microparticles wearing off and entering our food. However, the effects of this are not at all obvious - people are not dying in millions from agricultural plastics, used for example on the ground as weed suppression around strawberry plants. More research is needed. By comparison with other uses of plastic in agriculture, the scale of this is tiny. - Copper internal wiring and connectors. Copper has been used for centuries as a crop spray, and it is permitted in nearly all "organic"/"green" farming certifications. - Silver, in tiny amounts as top conductors on panels. Has antimicrobial properties in certain chemical formulations, but note the "tiny". Almost certainly benign, and if there is enough of it in the soil (well below any possibly toxic level) it will be recovered for re-use. - Trace amounts of "exotic" elements in the silicon. If these make their way into the soil, it will be in concentrations of parts per trillion, likely far below background levels already in the soil. (Some of these are things like phosphorus which is an essential nutrient anyway.)
- Schroedingersat 3y ago
  There is lead too in some, but even if it all somehow teleported out of the module and directly into the soil (as opposed to this never happening) it would be 10% as much as was already in the soil naturally before leaded gasoline was a thing.
Schroedingersat 3y ago
That's because it's a purely imaginary problem shills invented. Vastly higher quantities of toxins and heavy metals come out of the tractor exhaust than will somehow teleport through glass and time-travel from obsolete chemistries.

by lpapez 3y ago

hosh 3y ago

There are plants that can do soil remediation on soil with heavy metals, though you can’t eat them and you still have to find a way to process or sequester the heavy metal. Cilantro (coriander) is an example.

kibwen 3y ago

Iron is often used as a fertilizer, so rusted support beams aren't a problem, either for the plants or for humans. And all the interesting parts of a solar panel are under glass, they aren't being washed away by rain.

hannob 3y ago

Rust is just iron oxide, which in small quantities is a relatively benign substance. And probably there's more rust coming from old farming equipment than from the (likely high quality, because they are built for expensive solar panels) steel structures here. The solar cells themselve are mostly made out of silicon, which also isn't a dangerous substance. I don't think this is an issue.

sigstoat 3y ago

the solar facilities i'm familiar with use aluminum beams for the structure. it is more than strong enough, lighter so it is easier to install/ship to site, and requires no special treatment to survive the environment for more than the life of the installation. the panels themselves do not contain steel, either. > And I bet steel is the least toxic element of the panels. perhaps, but nothing on the panels comes off. they're solid objects largely impervious to all forms of precipitation. more of your house washes away in a storm than comes off a panel.

tuatoru 3y ago

Steel structural members used outdoors are coated, normally with zinc (called galvanizing). You see rust when the galvanizing has been corroded through. Sometimes a zinc + aluminum alloy is used as it lasts longer than pure zinc. You should be more worried about those elements washing into the soil. But it turns out that zinc is an essential micronutrient (as is iron) and aluminum is a large part of clay soils anyway. Other components of solar modules, roughly in order of mass:- - Glass. This is heavily purified and baked soil. Not a problem. - Silicon. This is the reduced metallic form of dirt, the equivalent of steel compared to rust or iron ore. Rusted silicon is all around anyway. - Aluminum wires and connectors. Already covered. - Plastics used to insulate wiring. Here we might have a problem, with microparticles wearing off and entering our food. However, the effects of this are not at all obvious - people are not dying in millions from agricultural plastics, used for example on the ground as weed suppression around strawberry plants. More research is needed. By comparison with other uses of plastic in agriculture, the scale of this is tiny. - Copper internal wiring and connectors. Copper has been used for centuries as a crop spray, and it is permitted in nearly all "organic"/"green" farming certifications. - Silver, in tiny amounts as top conductors on panels. Has antimicrobial properties in certain chemical formulations, but note the "tiny". Almost certainly benign, and if there is enough of it in the soil (well below any possibly toxic level) it will be recovered for re-use. - Trace amounts of "exotic" elements in the silicon. If these make their way into the soil, it will be in concentrations of parts per trillion, likely far below background levels already in the soil. (Some of these are things like phosphorus which is an essential nutrient anyway.)

Schroedingersat 3y ago
There is lead too in some, but even if it all somehow teleported out of the module and directly into the soil (as opposed to this never happening) it would be 10% as much as was already in the soil naturally before leaded gasoline was a thing.

Schroedingersat 3y ago

That's because it's a purely imaginary problem shills invented. Vastly higher quantities of toxins and heavy metals come out of the tractor exhaust than will somehow teleport through glass and time-travel from obsolete chemistries.