Solar power windows: Connecting scientific advances to market signals

Recent materials advances have enabled researchers to envision and develop highly efficient, partially transparent photovoltaic (PV) prototypes, exposing a potentially large and untapped market for solar energy: building integrated (BI) solar powered windows. In this perspective, we assess the case for market deployment of BIPV windows, specifically intended for commercial U.S. high-rise buildings. Research and development on solar powered windows has been predicated on the hypothesis that sunlight-to-electrical power conversion efficiency (PCE) and device cost per unit area are the key figures of merit that might drive market adoption. Here we investigate the market landscape and desirability for solar powered windows by identifying and evaluating the customer needs for the commercial high-rise building window market. In the course of this assessment, we performed 150 interviews with experts across the value chain for commercial windows. We found that the market forces are complicated by a misalignment of incentives between the end users of BIPV windows and the key decision makers for building projects that could incorporate this technology. Our assessment leads us to frame new figures of merit for BIPV windows that address the underlying needs of prospective customers as well as technical metrics for energy generation. We finally discuss one possible direction for BIPV window technology in which photovoltaics are integrated with switchable windows. Here, the integrated PV converts visible and infrared light transmission into useable electricity enabling standalone, self-powered active windows that can potentially address market needs for smart windows, thereby enabling a pathway for BIPV window deployment