How Residential Solar Film Works

What makes solar film unique is that it doesn't use an optical tint to block out sunlight. Instead, it is spectrally selective - the only true spectrally selective film on the market.

Sunlight radiates on a spectrum, of which only the middle is what we usually refer to as "sunlight" - visible light. The low extreme of the Spectrum is infrared (IR) and the high extreme is ultra-violet (UV). IR produces the majority of the heat we feel from sunlight. UV radiation causes skin cancer and fading.

Solar film selective blocks out 90% of IR, responsible for 65% of the sun's heat, and 99% of UV, while letting over 70% visible light in. 70% is exactly the amount needed for the eye to not be able to tell the difference between a clear window and a solar film window, between unfiltered sunlight and sunlight that won't heat up your home and damage your skin.

The technology behind solar film was originally developed for US aerospace programs. It uses a technique called "sputtering" which embeds tiny particles of exotic metals in optically clear polyester film.

Popular Science recently named the technology behind solar film as one of the most scientifically significant products of the last thousand years. Its energy saving potential is recognized by the Department of Energy through its Energy Star program and it qualifies for rebates on installation from major utilities such as PG&E.