It's mostly silicon, how bad could the waste be?
Solar modules contain lead for soldering and some contain cadmium telluride (CdTe).[1] If handled and recycled correctly, the risk of exposure of lead and cadmium into the environment is minimal. However, there is a possibility that such materials are released by accident (fire, cracks) or improper disposal. That is why there are demands that solar modules containing CdTe should be basically abandoned, as there exist…
Not all of them, and lead is also non-essential. Most solder in other contexts is already lead-free. It's also pretty minor compared to the other sources of lead in our lives already.
> some contain cadmium telluride (CdTe)
only "thin film" cells, which are virtually obsolete- they're the flexible kind that you get in "cell charging" backpacks and stuff. Price decreases in silicon in large-scale use, so they have absolutely no bearing on renewable energy. They're not worth mentioning- a 100x increase in solar power will not increase the amount of cadmium cells at all.