Top-down Energy Modeling

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 associ-
ates that data with the corresponding energy consumption.
The purpose of this article is to discuss the advantages and disad-
vantages of each modeling technique, with the result that the top-down
model is preferred on the basis of cost, time to construct, model opera-
tion, model maintenance effort, accuracy, etc.