Energy consumption of personal computer workstations

Technical Report · Fri Dec 01 04:00:00 EST 1995

OSTI ID:254598

Szydlowski, R

An important question for consideration is, {open_quotes}Are office equipment plug loads increasing?{close_quotes} Data taken by Pacific Northwest Laboratory (PNL) in May 1990 from the Forrestal Building, the U.S. Department of Energy (DOE) headquarters in Washington, DC, are desegregated by end use including: plug loads, lights, HVAC, large dedicated computers, and elevators. This study was repeated in November 1993, and there was a 3.8%/yr increase in plug loads in a building of approximately 1.75 million sq ft. Subsequent to this measurement, the plug loads were measured continuously by PNL over a 10-month period from November 1993 through September 1994, and the results showed another increase of 3.9%, nearly the same increase as in the previous three years. The energy use of personal computers (PCs) was measured by setting up a mobile outlet module (MOM), a replacement for a strip outlet, with current transformers (CTs) and potential transformers. The MOM was connected to a set of dataloggers, allowing for the monitoring of up to four PCs at a time. The PCs were plugged in through the MOM to a C180 datalogger, the data collected to a laptop, and the individual 24-hour profiles were then reduced to a standard profile. About 200 workstations were studied, including the PC, monitor, printer, modem, external disk drives, and CAD systems with their own peripherals. Also monitored were an additional collection of printers, photocopiers, facsimile machines, and monitor controllers. The end result was a set of profiles for energy use during working hours for five different buildings. There was a wide variation in these profiles from daytime to nighttime, since 16 to 35% of the computers remain on at night. Therefore, the needs for computers left on at night vary, along with the attitudes of people. Another area of energy consumption concern is the type of PC, such as IBM- or Macintosh-compatible, and there are many different kinds of workstations.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States); Policy Research Associates, Inc., Reston, VA (United States)
• OSTI ID: 254598
• Report Number(s): EPRI-TR--105549; CONF-9410439--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
ELECTRONIC EQUIPMENT
ENERGY CONSUMPTION
MONITORING
OFFICE BUILDINGS
PERSONAL COMPUTERS
US DOE