Smart Window Simultaneously Generates Electricity & Lowers Energy Costs

Smart windows can vary their tint to augment lighting, cooling, and heating systems in buildings to save in energy costs. But these windows require power for operation and can be complicated to install in existing buildings. Now, engineers at Princeton University have developed a smart window system featuring solar cells that selectively absorb near-ultraviolet light - so the windows are completely self-powered. The piece of the glass shown in this video harvests one portion of the light spectrum to control other parts of the spectrum. Specifically, it uses near-UV light to generate electricity, which powers chemical reactions that lighten or darken the glass as needed. When darkened, the window can block more than 80 percent of light. To learn more, read a Tech Briefs Q&A with the inventors.