Encouraging Energy Stewardship: An Analysis of Energy Use and Environmental Impact of a Campus Computer Classroom at Bethel University, St. Paul, MN

Robert Kistler
&
students in GES325K—The Planet Earth: Environmental Stewardship

http://www.bethel.edu/~kisrob/CampusEnvironment/computers/computers.htm


Introduction

Computers use in K - 12 schools and on college and university campuses has been rapidly expanding in the last 10 years (Figure 1). While the size, cost, and energy efficiency of these computers have all been declining, the impact of these computers on the environment has been escalating simply due to the rapid increase in numbers in homes, schools, and the workplace. The computer was originally touted as an environmental benefit, bringing about the paperless society, while in reality the use of computers have exponentially increased the use of paper not just in education, but in all settings. Likewise, the advent of "green" computers with EPA energy star ratings (http://www.epa.gov/energystar/) were thought to minimize impact on energy use and pollution output. However, in many educational and institutional settings, there is little awareness of or emphasis on conservation among staff responsible for installing and maintaining academic computing environments, leading to a heavy increase in energy use and subsequently leading to increased pollution output. The U.S. Department of Energy (DOE) expects the use of office equipment to grow 500% in the next decade from the current 7% of the of the total commercial sector energy use. (DOE, Energy Smart Schools, Building Resources, http://www.eren.doe.gov/energysmartschools/elements_comp.html). A growing need exists for all education institutions to analyze and consider the impact of this growing energy use on budgets, resource consumption, and environmental impact.

Figure 1. Students are increasingly using computers at their schools as is indicated by the use of internet in schools. [Figure from Wirt et al. 2000. The Condition of Education 2000. National Center for Education Statistics, NCES 2000-062. http://nces.ed.gov/pubs2000/2000062.pdf

 

Purpose of Study

GES325K is a General Education course in our Science, Technology, and Society category. The course is junior level with a prerequisite of a Laboratory Science Course in either biology, chemistry, or physics. The students have thus been introduced to science as a way of knowing in society and have had some experience in the laboratory of doing science. However, the students come from a variety of lab science courses and from a variety of major fields of study. GES325K uses the field of environmental science as a backdrop to examine the ways that society can minimize environmental impact using both modern science and technology and good societal practices. During Fall Semester 1999 the class met in a technology classroom outfitted with 23 Macintosh 6500 computers (Figure 2).

Figure 2. The computer classroom under analysis. Figure 3. Model PK-VIP-1-mx Power Line Meter. The appliance to be tested is simply plugged into the meter.

During our discussion about the use of energy in society today, students begin to wonder about the energy impacts of the computers in our classroom. Based upon student observations that the computers were on 24 hours a day and never seemed to go to "sleep" in an energy conservation mode possible on these computers, students contacted Academic Computing Services personnel and discovered that all energy saving features such as the low energy "sleep" mode and the automatic shut down/start up features had been disabled for ease of "use and administration". Students wanted to collect some data to understand the costs of these administrative decisions and to see if they could not encourage the re-implementation of the energy saving features on the classroom computers.

Methods of Study

One of the computers in the classroom was unplugged and both the computer and its monitor were plugged into a power-strip that was then plugged into a Power Line Meter (model PK-VIP-1-mx, RS232, Electronic Product Design, Inc., Springfield , OR)(Figure 3). This particular meter allows a wide diversity of electrical and energy parameters to be measured (RMS voltage and current, Watts, Watt-hours, peak voltage, peak current, volt-amps, power factor, and VARS). We then connected the RS232 connection on the Power Line Meter to the serial port on a PC laptop (Acer Extensa 7100DX pentium II) on which Serial Software, a virtual instrument, data acquisition program supplied by Electronic Product Design, had been previously installed (Figure 4). Once the program was actively acquiring the data from the meter, the power strip was turned on and data was collected during full power mode, sleep mode and off mode (Table 2). Students exported the data to a spreadsheet program to ,graph the logged data (Figure 5).

 

Table 1. Sample data as recorded from the Power Meter by the Serial Software(channel headings added to columns).

Time

RMS V

Peak V

I

Peak I

Watts

Peak Watts

Power Factor

Hours

Watt Hours

7:11:51AM

120.4

165.7

.298

.70

24.6

117

.68

000.34

000001.14

7:11:53AM

120.6

165.9

.297

.73

25.7

122

.71

000.34

000001.17

7:11:55AM

120.6

165.9

.295

.72

25.2

120

.70

000.34

000001.17

7:11:57AM

120.4

165.7

.297

.70

24.4

116

.68

000.34

000001.20

7:11:59AM

120.5

165.8

.295

.74

25.2

122

.70

000.34

000001.20

7:12:01AM

120.3

165.6

.297

.71

24.5

118

.68

000.34

000001.23

7:12:03AM

120.5

165.9

.296

.73

25.2

122

.70

000.34

000001.23

7:12:06AM

120.3

165.6

.296

.70

24.3

115

.68

000.34

000001.26

7:12:08AM

120.4

165.5

.295

.70

24.8

115

.69

000.34

000001.26

 

Figure 4. The entire analysis connections. The computer and monitor are plugged into the power strip and the energy meter is plugged into an outlet. The power meter outputs data to the laptop. On the left is a screen shot of the virtual meter on the PC.

 

Figure 5. The energy use and impact of a computer classroom, AC203 Bethel University, with 23 Power Macintosh 6500/250Mhz computers. The energy use analysis was done by students in GES325K The Planet Earth: Environmental Stewardship. The cost to both the University and the environment is maximized since at the time of the study all energy saving features were disabled by campus computing staff for "ease of administration and use".

 

Conclusions from the study

The students concluded from these data that (1) computers use a significant amount of energy, (2) even when the computers were "off", they used significant power (24 watts), (3) in sleep mode the energy use is approximately halved, and (4) the school could save about $600 per year by reinstating the energy saving features on these computers. By allowing the computers to sleep when they are not in use and allowing the computers to auto-shutdown/startup during the times the classroom is not in use (11:00pm - 8:00am and weekends) there would be both significant monetary savings and significant environmental savings as well as a potential increased in longevity for the computer.

The students then took these data in the form of Figure 3 to the head administrator of Academic Computing Services who then took steps to reinstall some of the energy saving features. I have since allowed students in other classes to roam the campus and their residences with a simpler power meter (Watt/Watt-Hour Meter, Model EM-1, Electronic Product Design, Inc.) and they have come to the conclusion that we can drastically decrease our energy consumption at both the individual and institutional levels with some simple, wise and informed choices made using the data that energy monitoring with these simple power meters can provide. Examples of other college campuses analyzing energy efficiency are beginning to appear (Humber College, Energy Management Action Plan, http://199.71.68.106/energie/actions/humber_emap.htm; DeCarolis, J. F., R. L. Goble, & C. Hohenemser 2000. Searching for energy efficiency on campus: Clark University's 30-year quest. Environment 42(4):8-20).

©Robert Kistler, June 5, 2000
Last Updated 11/22/06