Elevators in Europe have an annual overall energy requirement of around 18 TWh, and thus consume about as much electricity as the German rail network does. This could be reduced by half if efforts to lower standby consumption and introduce new technologies are successful. However, a lack of knowledge and, frequently, the “investor-user dilemma” have often been barriers to the implementation of improvements up to now. These are the conclusions of scientists participating in the “Energy efficient elevators and escalators” EU project, which was coordinated by the University of Coimbra, Portugal. The Fraunhofer Institute for Systems and Innovation Research (ISI) from Germany has also contributed to the research work, the results of which can now be downloaded from the project website.

Elevator equipment is estimated to be responsible for between 3 and 5 percent of the overall electricity consumption of buildings. There are three contributing factors here:

• The power consumption during standby
• The power consumption when the elevator is moving
• The frequency of use
   

The researchers have identified significant potential for optimisation, particularly with regard to energy consumption during standby periods. On average, elevators in residential and commercial buildings consume around 70 percent of their overall energy requirement while on standby. The figure is lower for office buildings because elevators in these buildings are used more frequently, but is nonetheless still at a high level of 40 percent. Measurements carried out on elevator equipment in various types of buildings around Europe showed up widely differing consumption levels, ranging from significantly below 100 watts to over 700 watts. These differences can be explained by the varying efficiencies of the components used and by the differing designs and features of the elevators.

Planning and design largely determine the energy efficiency over the entire lifecycle of the equipment. Considerable potential for savings can be exploited over many years if energy-efficient components are chosen and intelligent control of these is implemented. Manufacturers and operators often lose sight of this aspect, particularly as the investor will generally not be the building user. In addition, the energy costs for elevators are often shared in buildings occupied by a number of parties and are thus not accorded much attention.

Background

In the 27 EU states, there are currently around 4.8 million elevators in use for various purposes – such as the provision of convenient, barrier-free transport between two floors in a building, for access in high-rise buildings with height differences of several hundred metres, or for transporting heavy loads in industrial buildings. There are around 650,000 elevators in Germany, with two-thirds of these in residential buildings.

Research report

The research results regarding the improvement of the energy efficiency of elevators and escalators in office and residential buildings can be downloaded at www.e4project.eu.