Are ZEBs possible on a wide scale? To answer this question, NRELresearcherstook5,375buildingsin1999Commercial Buildings Energy Consumption Survey (CBECS) public use data,7 extracted the key energy-related building parameters, and created energy models to simulate the energy performance representing the entire commercial building sector. We used Standard 90.1-2004 performance requirements for all of the building models to use as a baseline, then applied a set of readily available energy
conservation measures and covered 50% of each simu- lated roof with photovoltaic (PV) panels