Top–down Energy Modeling

Abstract

ABSTRACT There are two fundamental approaches to modeling a facility's energy consumption: top-down and bottom-up. The bottom-up model requires metering installation and an exhaustive inventory of all facility equipment, as well as the energy consumption pattern of each facility device. To determine a facility's total energy consumption over any period of time, it's only necessary to sum the energy consumption of all the facility's equipment. The top-down model uses the high-level information that a facility routinely collects regarding its activities and performance, and associates that data with the corresponding energy consumption. The purpose of this article is to discuss the advantages and disadvantages of each modeling technique, with the result that the top-down model is preferred on the basis of cost, time to construct, model operation, model maintenance effort, accuracy, etc.