Solar panels have made great progress in recent year, changing from bulky panels to tinted glass.  But, the National Renewable Energy Laboratory (NREL) of the United States Department of Energy is now one step ahead. NREL recently announced the invention of a solar energy glass that provides shading and energy generation when the temperature rises. 

The appearance of this special solar energy glass will change when exposed in sunlight, caused by the radiation of specific molecules under heat. The methylamine molecules stored in the switchable layer are driven out in responding to heat by transforming from transparent to tinted.   As the window darkens, it generates electricity. The photosensitive glass will block 97% of visible light in darkened state, comparing to 33% shading rate in its transparent state.

When sunlight or heating unit is moved away from the window device, it will cool down. The methylamine molecules re-absorb into the window material and the glass appears transparent.  Even in darkened state, this thermochromic glass will still achieve a solar power conversion efficiency of 11.3 percent, the highest in its kind.