TEC is an Energy Star measure (it evaluates typical weekly energy consumption of a product across all power modes while in normal operation) that is now calculated for most new MFDs and printers, and data on older devices (say, older than 5 years) can be found.
I suggest Beacon add TEC as a sustainability impact, and that the data be stored on a per-device level; aggregate electricity consumption data should be kept separate from the paper quantity electrical use in the sustainability pane of the dashboard. This would give Beacon much greater utility for calculating printing costs and savings from the sustainability perspective, and make it a very useful tool for assessment and analysis of changes in printing behavior (i.e., consolidation of multiple printers into fewer MFDs, replacing older printers with newer ones, etc.).
Here is the link to the Energy Star equipment specification that details TEC (and OM, "Operational Mode", which might be an alternate measure to consider: Imaging Equipment Specification : ENERGY STAR