"Automatic" Energy-Saving Sheet for Window Glass

The National Institute of Advanced Industrial Science and Technology (AIST) announced on 16th that the institute, in cooperation with Sumitomo Chemical, had developed a new energy-saving sheet for window glass.

Basically the sheet is to be put on window glass, and it can automatically avoid summer sunlight to penetrate the glass. It takes advantage of the difference of incidence angles between summer and winter sunlight.

The National Institute of Advanced Industrial Science and Technology (AIST): Press Release (in Japanese) 2013/05/16
http://www.aist.go.jp/aist_j/press_release/pr2013/pr20130516/pr20130516.html