In this photograph, workers install solar photovoltaic (PV) modules that are part of a 1.6-megawatt system, on the roof of the Research Support Facility (RSF) at the National Renewable Energy Laboratory. The RSF building showcases numerous high-performance design features, passive energy strategies, and renewable energy technologies. It is a prototype for the future of large-scale ultra-efficient buildings. With 19 percent of the primary energy in the United States consumed by commercial buildings, the U.S. Department of Energy's goal for the RSF project is to help change the way commercial office buildings are designed and built.