PV has been growing with a time constant short compared to the lifespan of PV modules, so most of the cumulative production is still in operation today.
This is also why PV recycling hasn't had a chance to really get going -- very limited potential input to the process yet.
Yes that's true. My point is simply that solar (in this early phase) does show exponential growth.
Spangry's "the growth rate becomes more rapid as the stock of the thing gets larger" was confused enough to made exponential growth sound vaguely absurd, but in fact it's perfectly expected (and indeed observed).
This is also why PV recycling hasn't had a chance to really get going -- very limited potential input to the process yet.