IBM taking two paths toward making solar power cheaper than fossil fuels | Ars Technica

The price of photovoltaic hardware has dropped so dramatically in recent years that, according to some projections, a well-sited panel may become competitive with fossil fuels before the decade is out. To reach that point, which comes when panels cost below $2 per Watt, prices will have to continue their steep decline. During our visit to IBM’s Watson research center, we talked to two people who are working on ways to drive the cost down—but they are taking radically different approaches. The panels that most people are familiar with use silicon as a semiconductor. That has a few advantages, like cheap raw materials and reasonably high efficiency. But manufacturing panels remains expensive, and there aren’t obvious ways of squeezing large gains in efficiency out of standard silicon. So, IBM is looking at materials that don’t involve silicon: thin films and concentrating photovoltaics.