How solar panels could capture a lot more sunlight on slanted roofs

Most of the solar panels in the world sit on rooftops at a fixed angle, so they miss out on capturing energy during parts of every day. Now researchers have shown that by cutting solar cells into specific designs using kirigami, a variation of origami which entails cutting in addition to folding, they can allow the cells to track the sun's angle without having to tilt the whole panel. This could have a substantial payoff: solar panels with tracking mechanisms can generate 20 to 40% more energy per year than those without trackers.

As shown in the video below, applying a specific kirigami cut creates strips in a solar cell. Pulling the two ends in opposite directions causes the strips to tilt and assume a desired angle. Crucially, the structure morphs in such a way that prevents the individual strips from casting shadows on the others, and the "waviness" of the new form does not detract from performance, says Max Shtein, a professor of materials science and engineering at the University of Michigan. Shtein led the research along with Stephen Forrest, also a professor of materials science and engineering at the University of Michigan. Read more...