Case Studies in Using Whole Building Interval Data to Determine Annualized Electrical Savings

Abstract

Whole building interval analysis to determine savings from energy reduction measures is addressed in several guidelines. The whole building method has typically focused on measured savings where baseline regression models are developed to project original operational characteristics to measured post implementation results. A normalized savings method is described in the same guidelines. The savings normalization uses baseline and post regression models with a common data set, such as TMY. Details in applying the normalized savings method are not described in the guidelines. The case studies presented in this paper attempt to use the normalized method to determine annual savings. Results show the normalized method produces the same savings percentage as the measured method, but the total energy usage and savings predicted was lower. Using 12, 9, 6 and 3 month post monitoring periods for the development of the post regression models yielded normalized realization rates of 87% to 114% when compared to the measured method results.