I always treat the phrase "circular economy" as a red flag, and I was proven correct again by this article. 

$18 per panel after subsidies? From a process that creates further waste that must be dealt with - N and P dopants cannot be economically removed from silicon, this waste is only potentially useful for steelmaking, an industry already oversupplied with low-grade silicon waste from semiconductor manufacturing.

Aluminium, and copper wire are nearly always worth recovering, but the balance of the panels belongs in landfill.

We are not short of raw sand and bauxite. Or holes in the ground.

We are short of energy - globally - and wasting large amounts of energy to prevent the use of small amounts of raw materials is environmental vandalism, economic madness, and serves only to promote poverty.