Imagine how nice it would be on a hot summer day to be able to automatically cool one’s environment with solar panels — and then to have the same panels provide warmth when autumn comes. This concept is not such a fantasy anymore, thanks to research being conducted at Rensselaer Polytechnic Institute (RPI) in Troy, N.Y.Solar panels that provide both heat and cooling are under test in this rooftop prototype. Courtesy of Steven Van Dessel, RPI.Architect Steven Van Dessel and colleagues are working on a system that converts sunlight to electricity. Depending on the direction of the current sent to the thermoelectric heat pumps, it would provide heat or cooling.The technology, called Active Building Envelope, is being tested in a prototype structure, and the researchers are working on miniaturizing the system into a thin film based on photovoltaic cells. They envision a transparent coating or glaze that could be applied to both new and existing structures. They anticipate eventual applications not only for building construction, but also for automobiles, spaceships and, perhaps, for self-cooling bottles for drinks.The system, if commercialized, should find avid human fans — and should put a lot of mechanical ones out of service.