Lighting, heating and cooling are the big three pillars of energy efficiency programs, but there’s a fourth that’s edged its way into the discussion – plug load. In fact, in office buildings that have improved the performance of lighting, heating and cooling, plug load can represent 50 percent of total electricity use.
Plug load is simply the myriad of devices connected to power strips that run the digital economy, with computers, monitors and printers being the most common.
A few simple steps are highlighted in the report: enable aggressive power management settings, which must be set by the operator; educate staff on how to activate the lower power modes, or have IT managers explore network power management software that can be configured to start up on login without disrupting systems; stay on top of settings; and activate sleep settings across networks of computers.
The energy savings can be striking. As an example, a typical Energy Star v4.0 qualifying printer/fax/scanner that was in “active” mode but used less than 4 hours per day was switched to an “idle” setting that allowed quick-starting reduced energy use by 64 percent; “sleep” and “standby” modes applied during long periods of inactivity and overnight further reduced energy use by 88 to 98 percent.
Another significant step to reduce office plug loads is to better manage computer server rooms, which are responsible for wasting massive amounts of energy. The focus may be on large data centers, but possible savings in smaller server rooms and closets are often overlooked.
According to the Environmental Protection Agency, typical servers in the US use only 5–15 percent of their maximum capability on average, while consuming 60–90 percent of their peak power.