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An actually interesting bit of greenery

Not that there are all that many end of life solar cells currently, but there will be soon enough:

New research has proposed a cost-effective way to recycle solar panels to help handle an increasing volume of retired photovoltaic (PV) cells expected by the end of the decade.

In a paper published by a team from the University of New South Wales last week, researchers outlined a process to collect and extract valuable materials from solar arrays to see if it was technically, economically and environmentally feasible.

The process involves collecting solar arrays, stripping them of their aluminium frame, shredding the cells and using an electrostatic separation to collect valuable materials including silver and copper, reducing the panels to 2%-3% of their original weight.

The reclaimed material would then be shipped directly to a refinery for purification and processing.

Well, no, they’re not reducing the panels to 2 to 3% of their original weight. They’re stripping out the 2 to 3% that’s worth recycling, the rest goes to landfill (glass, plastic etc).

The process consists of module deframing, laminate shredding and material concentration using electrostatic separation. The latter outputs two fractions: a valuable mixture of silver, copper, aluminum and silicon, and a mixture of mostly glass, silicon and polymers. The valuable mixture accounts for only 2-3 wt% of the total module, which can be forwarded to the downstream industry for further refinement.

Now, of course, it’s a bit premature yet. But assume the paper actually stands up. The metals industry would happily take the Al/Cu/Ag/Si mix. Probably dump the Si along the way but still. Cu/Ag is old hat, a way to sift out the Al probably exists.

To be honest, if I knew of a 1 or 2 k tonnes a year stream of solar panels that could be had I’d probably try to set one of these little plants up. Because it would be a little plant. 5 tonnes a day of processing sort of size. Perhaps ship in a container sort of size.

9 thoughts on “An actually interesting bit of greenery”

  1. But what about all the metals that could be recycled to make more solar panels such as indium, gallium, selenium, cadmium, and tellurium?

  2. Depends which sort of solar cell you’re talking about. Cd/Te is an entirely different technology, for example. In and Ga, well, high end stuff, maybe, but not necessarily in standard.

  3. Things that use In and Ga are layers of those materials a few atoms thick usually, though there may be more in the base material. I doubt they are worth the effort of recycling. The Si certainly isn’t.

  4. jgh: (assuming no /sarc tag on that) I don’t think the photovoltaic stuff wears out, but the frames wear and the coverings scratch, etc. So they get less efficient.
    I think recently it’s also been like computers – the new cells are much more efficient than the old, so it makes sense to replace them after a while.
    Not sure how much longer that will happen; I think they’re getting close to theoretical limits.

  5. @M Not quite close to theoretical limits, but setups with even higher efficiency have as yet never left the Lab™.

    They’re pretty close to technological limits nowadays though.

  6. @Ducky McDuckface
    Wasn’t there something in the last couple of weeks about a 50%~ish jump in panel efficiency by using perovskite? Or something

    In ten years, like fission; and now mRNA jabs to cure cancer – if you survive the heart attacks & strokes

  7. Perovskites have a problem with oxygen and water attacking them. Unless you can come up with an absolutely bulletproof hermetic seal, they fail rapidly. Remember these things have to last 20 years in a rooftop environment and be reasonably cheap.

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