PV using dedicated silicon wafers is starting about now. These wafers will have way more impurities than VLSI grade wafers, and the PV will go down a bit in yield, but the panels should be much cheaper after a couple of years (like 2-3 times per peak watt I expect). Also, they will be decoupled from VLSI economic cycles (by which production of PV basically stopped whenever their was an expansion of the microchip business, every 3 years or so)

Pierre