Lighting consumes 33% of electricity used in commercial buildings. The next few columns will discuss energy effi cient lighting. From an electrical engineer’s viewpoint, energy standards such as ANSI/ASHRAE/IESNA Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings, are great equalizers. As the need for more electrical equipment in most buildings increases to feed our computers and information processing equipment, energy effi ciency standards decrease our demand for energy used to heat and light our buildings.