The earth's crust is 60% silicon dioxide. I don't understand how we could possibly run out.
I mean, I get the value in recycling the panels. It's presumably easier to start with almost pure material than 60% pure. Still, if it were cheaper to start with a chunk of feldspar than an old panel, I don't think we'd have to worry about the lack of virgin materials.
The air is 21% oxygen and hospitals were running out of oxygen in some places during the COVID pandemic. Hydrogen is the most abundant element in the universe, and yet, the supply of hydrogen is one of the biggest hurdles to the adoption of hydrogen cars.
Just because a resource exists nearby doesn't necessarily mean it can be harnessed economically or within the other constraints that the world and society imposes on us.
Silica mines are mostly (all?) surface mines, we don't explore anywhere into the crust to get it now because it isn't economical to do so. "Running out" of supply doesn't necessarily mean that the element doesn't exist, it could mean that it is inaccessible for other reasons -- like it could be the beach in front of someone's house, or a protected park.
It's also not clear if recycling the silicon in PV cells into new PV cells is the best way to recycle it. The world also uses silicon in silicon steels and in the manufacture of silicones. As PV is further scaled up these may not be large enough markets, granted.
This comparison is incomplete without thinking about what happens to the disposed-of panels. Panels in landfills are pollution as much as anything else
I mean, I get the value in recycling the panels. It's presumably easier to start with almost pure material than 60% pure. Still, if it were cheaper to start with a chunk of feldspar than an old panel, I don't think we'd have to worry about the lack of virgin materials.