Quantifying National Energy Savings Potential of Lighting Controls in Commercial Buildings
Lighting has the largest estimated technical potential for energy savings of any U.S. building end-use. A significant fraction of that potential is believed to lie in lighting system controls. While controls are incorporated in national model building codes, their adoption and enforcement are spotty, and controls have been largely ignored in energy efficiency standards, leaving much potential untapped. The development of sound energy policy with respect to lighting controls depends on improved quantification of potential savings. Researchers have been quantifying energy savings from lighting controls in commercial buildings for more than 30 years, but results vary widely. This meta-analysis of energy savings potential used 240 savings estimates from 88 published sources, categorized into daylighting strategies, occupancy-based strategies, personal tuning, and institutional tuning. Beginning with an average of savings estimates based on the entire literature, this research added successive analytical filters to identify potential biases introduced to the estimates by different analytical approaches. We obtained relatively robust final estimates of average savings: 24% for occupancy, 28% for daylighting, 31% for personal tuning, 36% for institutional tuning, and 38% for combined approaches. Using these data and estimates of current and full penetration of controls, we calculated national energy savings potential on the order of 19%.