While many efficiency efforts have targeted lighting and HVAC applications, plug loads have been growing, especially as a percentage of total energy consumed in commercial buildings.
According to the New Buildings Institute (NBI), today’s most efficient office buildings have plug loads that can represent as much as 50% of total electricity usage (see chart). As recently as 2003, plug loads averaged only approximately 15% of total usage in office buildings.
NBI’s Plug Load Best Practices Guide has ideas for reducing plug demand, including smart power strips with occupancy sensors and load-sensing strips that turn off all devices when the computer is switched off.
Other suggestions include software that initiates low power settings across networks of computers. Also consider laptops because they typically use a third of the energy of a desktop with monitor. Another source of waste is the computer server room. EPA estimates that typical U.S. servers use only 5–15% of their maximum capability while consuming 60–90% of their peak power. By increasing the load on each server and reducing the number of servers, significant energy could be saved while performing the same work.
The Plug Load Best Practices Guide is available at www.newbuildings.org.