The windows Peer+ plans to manufacture have three settings: dark, diffuse and light. In the dark and diffuse settings, the incoming light is used to generate energy. Teun Wagenaar is one of the company’s founders. The main advantage of this technology, in his view, is that the product can be quickly introduced on a large scale. “It is an excellent way to make large buildings greener,” he says. “The facades of big buildings can easily have 1,000 m2 of exposed glass. The amount of energy you can save on air conditioning and lights in such a building is tremendous. Plus, you can generate electricity at the same time. This application could greatly reduce carbon emissions.”