MIT Technology Review reports,

By the end of the decade, manufacturers in the United States could make solar panels that are less than half as expensive as the ones they make now.

Would that be so impressive? Compared with Moore’s Law, it’s a snail’s pace. And here is the kicker:

To make solar power more competitive, installers will also need to reduce costs. Installation and the cost of inverters, wiring, land, and financing account for half–and sometimes as much as 80 percent–of the cost of solar installations. Much of this needed cost reduction could be achieved by improving efficiency, which would reduce the number of panels needed in a project.

I was more optimistic about solar power five years ago than I am today. I agree that when solar power becomes competitive with fossil fuels, it is likely to continue improving more rapidly, so that energy usage patterns will change sharply. But I would push the date for that out past 2025.