The energy consumed by an escalator can be logically subdivided into two main components. The first component depends on the vertical rise of the escalator and its mechanical and electrical design. This component has been denoted as the fixed power losses. It is the power that is drawn from the supply when the escalator is running unloaded (regardless of the direction of travel). The second component depends on the vertical rise of the escalator and the number of passengers using the escalator per day as well as their walking behaviour. This component has been denoted as the variable power losses for an upward moving escalator (or variable power gains for a downward moving escalator). The formulae used to calculate both components are derived based on power measurements on a large group of escalators in addition to a number of passenger count surveys on a selection of escalators (synchronised to the power measurement data). Further analysis is carried out into the phenomenon of passengers walking on escalators and its effect on the overall energy consumption. (C) 2011 Elsevier B.V. All rights reserved.