Behavior Oriented Metrics for Plug Load Energy Savings in Office Environment

Plug load energy consumption represents up to 40% of the total energy consumption in efficient buildings. Occupant behavior has a huge impact on plug load energy consumption. Studies have shown that up to 40% plug load energy savings can be achieved through users’ engagement in sustainable behaviors. To save energy from plug loads, either a company can replace their appliances with more efficient ones, or an occupant can change his/her behavior to control them more efficiently. Existing metrics such as Energy Use Intensity (EUI) cannot sufficiently evaluate behavioral impacts on energy use. To address this issue, a set of Metrics of Sustainability is developed for an Intelligent Dashboard for Occupant (ID-O) to integrate both company policy and individual behavior towards sustainable practices in office spaces. Through the ID-O, occupants can control their appliances and monitor energy consumption. The Metrics include (1) appliance selection, (2) effectiveness of occupant behavior, and (3) intensity of useful energy consumption. Occupancy status is one important input factor for the effectiveness determination. An occupancy detection method is proposed by mining the office appliance energy consumption data. The Metrics of Sustainability and method for occupancy detection are tested at two office buildings in Pittsburgh, PA. The results suggest that, (1) the Metrics are novel, practical and unbiased to evaluate occupants’ behavioral impact on plug load energy; (2) 23% of energy savings were achieved by integrating the Metrics of Sustainability with the ID-O during the study period; and (3) the occupancy detection method is feasible for use in office spaces.