Plug Load Control: Advanced Power Strips Decrease Energy ConsumptionGSA Public Building Service, November 11, 2013
Desk-based technologies and other electronics that plug into office building receptacles draw a considerable amount of power, some of it 24/7. In fact, “plug loads” account for roughly 25% of total electricity consumed within office buildings. GSA currently owns and leases more than 370 million square feet of building space in some 9,600 buildings nationwide. The size of this real estate portfolio alone suggests the possibility of enormous energy savings, if plug loads can be reduced. With this in mind, GSA’s Green Proving Ground (GPG) program recently assessed the effectiveness of advanced power strips (APS) in managing plug-load energy consumption in eight of its buildings. Three types of plug-load reduction strategies were evaluated: schedule timer control, which allows the user to set the day and time when a circuit will be energized and de-energized; load-sensing control, which monitors a specific device’s (master) power state and de-energizes auxiliary devices (slaves) if the master’s power consumption dips below a predetermined threshold; and a combination of the two. Results underscored the effectiveness of schedule-based functionality, which reduced plug loads at workstations by 26%, even though advanced computer power management was already in place, and nearly 50% in printer rooms and kitchens.