Plastic solar cells may indeed be gaining in efficiency, but here in the Southwest, anything plastic left out in the sun quickly clouds, desiccates, and cracks. Can the new polymer-based material protect against this destruction? It would certainly be cost prohibitive to replace the cells every year.

Stephen Wust
Santa Fe, N.M.

Researchers are well aware that, left alone, plastic solar cells won’t last long in the environment because the combination of light, oxygen, and water vapor degrades polymers. But the solution seems pretty simple. Some kind of transparent sealant or other encapsulating material would block out oxygen and water while letting through light. Companies and academics are working on it .—A. Goho