Much of the technology described in the report hasn’t been demonstrated at full production scale. The techniques for making wafers without sawing, in particular, face a number of issues, such as producing high enough quality silicon, making wafers in the right shape and size, or producing them reliably and at a high rate.

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.

Eventually, silicon solar panels could be even cheaper than 50 cents a watt, Buonassisi says. That will require finding ways to manufacture more challenging designs—for instance, including a nanostructured layer that improves light absorption, which would allow silicon cells that are only one micrometer thick to perform as well as conventional solar cells.