Insolight, a Swiss startup, has developed a thin plastic layer that sits on top of a solar panel and directs the sun’s rays to a small area of very high performance solar cells. The company says that the result is about double the efficiency of traditional solar panels for the same footprint.

The overlay is an injection-molded plate arrayed with plastic bubble lenses that act like a network of tiny magnifying lenses. These focus the light onto segments of the solar panel that are only several square millimeters in size. These areas contain some of the highest rated solar cells available, which yield 42% efficiency by capturing different wavelengths of light. Normally, these solar cells are prohibitively expensive but Insolight uses only a small number of the highly efficient cells.

The focusing plate is attached to a metallic frame that moves just several millimeters throughout the day, guided by a sensor that tracks the sun’s position. This micro-tracking system keeps 100% of the sunlight focused on the solar cells regardless of the angle of the sun.

The Fraunhofer Institute in Germany has independently validated performance of a prototype as achieving a yield of 36.4% – about double that of traditional solar panels with the same footprint.