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Office
equipment is one of the fastest-growing electricity uses in
commercial buildings in the United States. It directly consumes
seven percent of total commercial electric energy, which translates
into $1.8 billion in electricity costs to businesses [U.S.
Department of Energy. 2003. "Office
Equipment." Washington, D.C.: U.S. Department of
Energy]. This figure increases by roughly 30 percent if the
cost of air conditioning to displace the waste heat generated
by office equipment is considered. Furthermore,
energy consumption due to office equipment and related energy
systems is expected to continue to rise. By choosing energy-efficient
equipment, purchasers can save a substantial amount on their
office equipment electricity bill—as much as 90 percent
for products such as monitors [U.S. Department of Energy.
2003. "Office Equipment."
Washington, D.C.: U.S. Department of Energy]. While
less than a decade ago it was difficult to compare office
equipment on energy performance, today the ENERGY
STAR label makes it easy for purchasers to distinguish
energy-efficient office equipment products.
The ENERGY
STAR Office Equipment program—the first of the ENERGY
STAR product labeling programs—
was inspired in part by early studies revealing that many
personal computers are left on overnight and during the day
when they were not being used, and that energy use in these
machines could be reduced dramatically if they entered a low-power
state during periods of inactivity. As a result, standby power
is the target of the ENERGY STAR Office Equipment program
and power management features are the primary means by which
ENERGY STAR-compliant products save energy. Equipment eligible
for labeling under the program—computers,
monitors, printers, fax machines, copiers, scanners, and multifunction
devices—must
be capable of entering a "sleep" or low-power state after
a certain period of inactivity.
Since
the introduction of the program in the early 1990s, a broad
selection of office equipment with power management capabilities
has become available. ENERGY STAR-qualifying equipment is
available from most major manufacturers to meet a variety
of performance needs. Many manufacturers include the ENERGY
STAR logo in their product advertising, on product specification
sheets, and/or on display products in retail stores. Additionally,
the ENERGY STAR program maintains databases of qualifying
equipment. An overview of the ENERGY STAR requirements for
several types of equipment follows.
A
typical U.S. business with 100 employees may have
100 computers, 10 laser printers, 4 copiers, 4 fax
machines, and 2 scanners. By purchasing ENERGY STAR-qualified
equipment, this business can cut its annual electricity
costs by nearly $5,000 relative to an office with
equipment that does not meet ENERGY STAR labeling
criteria [U.S.
Environmental Protection Agency. 2001. Buyer's
Guide to Purchasing ENERGY STAR Labeled Office Equipment.
Washington, D.C.: U.S. Environmental Protection
Agency].
Desktop Computers (list
of qualifying equipment)
Power
management features initially available only in laptop computers
are now fully integrated into many desktop machines. Computers
enabled with these features use about 70 percent less electricity
than those without [U.S. Environmental Protection Agency.
2003. "Computers."
Washington, D.C.: U.S. Environmental Protection Agency]. Most
PCs today are ENERGY STAR-compliant and shipped with power
management features enabled. The ENERGY STAR specification
requires that labeled personal computers with an output power
rating of less than or equal to 200 watts power down to 15
watts after 30 minutes of inactivity. And those with an output
power rating of more than 200 watts must power down to about
10 percent of the power supply's maximum output power rating
after 30 minutes of inactivity, except for those computers
intended for networks, which power down to 15 percent to allow
for additional network activity. The most efficient computer
option, however, is the laptop computer, which typically draws
only 15 to 25 watts during use compared to the 150 watts used
by a conventional PC and monitor, and its sleep mode typically
uses just a fraction of a watt.
Additional savings can be achieved by enlisting employees
to turn off their computers at night and on the weekends.
In a pilot program operated for the City and County of San
Francisco, Lawrence Berkeley National Laboratory (LBNL) tested
the effectiveness of minimal user awareness on user behavior
with respect to turning off computers. E-mails were sent to
people in the target departments and posters were placed on
bulletin boards. The messages used emphasized the pollution
and monetary benefits of reduced electricity use, and stressed
turning off equipment at night. Behavior change was
significant in all cases, and was most pronounced where initial
behavior was to leave the most computers operating at night.
The study observed "leave-on" rates of under 10 percent for
personal equipment in an office with high environmental awareness,
and less than 5 percent in an office that had performed hands-on
user training. LBNL concluded that a persistent program
of user awareness may be able to achieve leave-on rates near
these levels in most offices, and maintain it over time.
Check
ENERGY STAR's site on power
management for more information.
Monitors (list
of qualifying equipment)
More
than half of the energy use of a desktop computer system is
attributable to the monitor. ENERGY STAR monitors have power
management systems that allows them to enter two successive
low-power states of less than or equal to 15 watts and 8 watts
after a period of inactivity. An ENERGY STAR-qualified
monitor uses 90 percent less electricity than a monitor without
power management. A common misconception is that switching
the monitor on and off five times or more a day increases
the frequency of faults in power transistors in the control
and deflection parts. Another common misconception is
that screen savers save energy. In fact, more often than not,
a screen saver will not only draw power for the monitor but
will also keep the CPU from shutting down. Similarly,
many popular computer games, when running in the background,
will not allow the computer to go to sleep, even if the game
is paused. Save energy on your computer monitors by
activating their power
management system and disabling screen savers and turning
off computer games.
Printers and Fax Machines (list
of qualifying equipment)
Computer
printers employ a variety of printing technologies, and within
each technology group, individual machines have a variety
of features that result in a wide range of energy consumption
patterns. ENERGY STAR printers power down to 10 to 100 watts
after a predetermined period of inactivity (5 to 90 minutes)
depending on the number of pages produced per minute, the
paper format (standard or large), and whether the printer
uses color. Power-managed laser and LED printers can use less
than half the energy of a conventional laser model. But ink
jet printers, which unlike laser printers do not apply a heat
fusing mechanism, use less energy than many of the current
energy-efficient laser printers. Because of their inherent
efficiency, the majority of ink jet printers currently available
easily meet the ENERGY STAR criteria without specific power
management features. According to the EPA, printers that have
earned the ENERGY STAR certification use 60 percent less energy
than others. Furthermore, it takes ten times as much
energy to make a piece of paper as to put an image on it.
Thus, ENERGY STAR requires higher capacity printers
(> 10 ppm) to be able to print on both sides of the sheet
(duplexing). This can save users paper costs and additional
energy that goes into producing paper [U.S. Environmental
Protection Agency. 2003. "Printers."
Washington, D.C.: U.S. Environmental Protection Agency].
Similar
to printers, facsimile (fax) machines employ a variety of
technologies including laser, direct thermal, thermal transfer,
and ink jet, which consume varying amounts of energy. And
while the energy use of any type of fax may seem low because
of its relatively low use, the fact that it is likely to be
kept on around the clock can generate significant costs.
ENERGY STAR fax machines are required to power down to 10
to 15 watts within 5 minutes of inactivity, depending on the
machine's output. By powering down, qualifying fax machines
can reduce energy costs associated with fax machine use by
almost 40 percent or an estimated $9 per year [U.S. Environmental
Protection Agency. 2001. Buyer's
Guide to Purchasing ENERGY STAR Labeled Office Equipment.
Washington, D.C.: U.S. Environmental Protection Agency].
Copiers (list
of qualifying equipment)
Copiers
use more energy per unit than any other piece of office equipment.
Absent power management features, the majority of this energy
use occurs during inactive operation. The ENERGY STAR program
addresses both off-mode and standby copier energy use by requiring
that copiers enter a low-power mode after brief periods of
inactivity (i.e., 15 minutes) and automatically shut off after
a specified longer period of inactivity. Specific parameters
for the automatic shut-off—the delay before the off-mode
is invoked and the power level the machine must achieve once
off—vary with the copier speed or size. Choosing a properly
sized copier can greatly decrease office energy use. Total
copier energy use typically increases with increased
copy volume capability. A mid-volume copier installed in a
low-volume office can in fact use much more energy per imaged
page than an efficient low-volume copier. Conversely, a high-volume
copier typically uses less total energy than multiple low-volume
copiers used to meet a high-volume office need. To qualify
for ENERGY STAR certification, then copiers must have a default
automatic duplexing feature. This not only reduces paper costs,
but also reduces energy used in paper production and paper
waste handling.
Scanners (list
of qualifying equipment)
ENERGY
STAR-qualified scanners enter a low-power "sleep mode" less
than or equal to 12 watts within 15 minutes of inactivity.
As a result, users save more than 50 percent of the equipment's
electricity costs. And as with other ENERGY STAR equipment,
compliant scanners run cooler and are thus expected to last
longer.
Multifunction Devices (list
of qualifying equipment)
Machines
that combine functions of several peripheral office devices
(e.g., printing, scanning, faxing, and copying) are becoming
increasingly popular, particularly among small users. These
machines can offer users significant energy savings by displacing
three or four separate machines with one. Depending on the
speed of the equipment (from 0 to 100 images per minute),
the ENERGY STAR program requires that multifunction devices
power down to between 25 and 105 watts after 15 to 120 minutes
of inactivity. By powering down, multifunction devices that
have earned the ENERGY STAR certification can reduce energy
costs by almost 40 percent relative to non-compliant equipment,
for an estimated $260 savings in electricity costs over its
lifetime. Similar to the copier requirement, higher speed
multifunction devices are required to automatically duplex,
reducing copying and paper cost.
Summary
To make
sure that you're getting the most energy and dollar savings
from your office equipment purchases, we recommend the following:
- Evaluate
your needs and avoid purchasing more or less power and capacity
than you're likely to need. This holds true for virtually
all office equipment, but the energy penalty is particularly
apparent with copiers, which if improperly sized for the
office load can waste considerable energy.
- In
all cases, purchase ENERGY STAR equipment. If a central
purchasing department is responsible for office equipment
purchases, work with that department to get ENERGY STAR
specified for all purchases. This does not place any
extra burden on purchasing staff as ENERGY STAR office equipment
is widely available in many stores and purchasing catalogs.
Purchasing language for specific equipment can be found
at the ENERGY
STAR Purchasing and Procurement website.
- Make
sure, however, that the device's power management features
are activated. While all manufacturers are required to ship
ENERGY STAR products with the features automatically activated,
it is still wise to verify that they have in fact done so.
If the equipment is being purchased for a whole section
or company, make sure the information systems staff, the
user, or whoever will configure the systems understands
how to make sure power management is enabled to maximize
the energy performance of the machines.
- Where
feasible, turn devices off at night or on weekends. Although
ENERGY STAR-qualified equipment in now widely available,
this option remains an important strategy for further reducing
office equipment energy use.
- Refer
to manufacturer literature or contact the manufacturer directly
if you have questions about the network compatibility of
your equipment. Manufacturers of qualifying equipment are
responsible for providing guidelines to consumers on the
network compatibility of their ENERGY STAR equipment.
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