A clearer view on display energy efficiency

Peer-reviewed paper 8-015-26

Displays, such as televisions, computer monitors and signage displays, are ubiquitous in our digital society and are becoming larger, brighter and more connected. The EU and other jurisdictions have regulated displays through energy labels and minimum efficiency measures, however with limited success in identifying higher energy efficiency products and increasing their sales. One of the reasons is that the test method used widely to date does not directly measure the efficiency of the display. Therefore, to prepare for a revision of the display efficiency regulations, a new test method has been developed that captures the light output and the power consumption of the display at the same time. Another problem with the current regulations is that displays can have many different pre-selected picture settings from which the user can choose. The out-of-the-box setting that is used in many regulations may not be the setting that is most used and is prone to manipulation.

This paper shortly introduces the new test method and then shows how the results can be used to calculate a metric that reflects the efficiency of a display. Ideally, such a metric should be technology neutral and independent from the other main characteristics of the display. The main display technologies and developments are presented. A dataset of measurements with the new test method is used to analyse technology independence and interdependencies between display characteristics. Finally, the paper provides an indication of potential energy savings and gives recommendations for implementing a metric in the EU regulatory context.