[jyl]

PV cells are made from silicon ingots similar to other semiconductors, although lower quality. Only a few companies make the ingots, and they were slow to invest the hundreds of millions required to increase production. For the past few years, supply has been tight and this has supported the price of PV cells. Supply is now coming online and silicon wafer prices are falling steeply. As are PV prices. The other big cost in PV manufacture is the capital equipment, which is something like a semiconductor fab though simpler. Here too supply is increasing, as fabs become obsolete they or the equipment in them can be repurposed for PV cell production. I expect PV prices will fall by 50 pct in a few years. With even modest efficiency increases, the PV cell portion of a PV system's cost should decline, in $/watt terms, by over half in the next few years. Installation and inverter costs are slower to fall, but there are lots of under-employed residential construction workers out there.