1. = Computer Power Consumption and Management on Kansas State’s Campus
“Earth, Wind, and Fire: Sustainable Energy for the 21st Century” Research Experience for Undergraduates
Emily Reinhard—Milwaukee School of Engineering, Electrical Engineering Undergraduate
Supervising Professors: Ben Champion, Ph. D and Noel Schulz, Ph. D, Kansas State University
Summer 2010
Project Description
Experimentation
Conclusions
Power consumption tests done with Watts Up? Pro ES power meter (measured in Watts +/- 1.5%) were:
With the growing concern for the environment, conserving energy is an important task for which society as a whole is responsible. Kansas State University is doing its part by exploring the energy usage by computers and looking for ways to save energy in the computer labs on campus.
Power consumption for a variety of user activities were quantified on two different computers: computers that are currently in the computer lab (Dell GX520) and Energy Star rated computers (Dell OptiPlex 380). From this data, potential energy savings were explored for the different computers and for different power management settings.
The goals of these experiments are ultimately to raise awareness of power consumption in computer labs, and to assist with the reduction of power consumption in Kansas State University’s computer labs.
Some key conclusions are as follows:
Phantom Loads
Computer Start Up
Monitor Start Up
Login
As expected power consumption is dependent on user activity (i.e load on hardware).
Putting computers into standby mode when inactive has huge energy saving potential on campus, using an average of 97% less energy.
Future research needs to be performed to find optimal power saving settings for Kansas State University’s public computer labs.
Phantom Loads
Computer Start Up
Web Browsing
Computer and Monitor Idling
Commodity Software (such as Microsoft Office)
Live Stream
Computer and Monitor Standby
Other Free Software (Media Players)
Specialty Software
Other things explored:
Power Factor of different computers and at different locations
Standby mode of different computers
Power consumption of different types of computers on campus
Using Standby Mode for 9 hours at night on Computers
Saves $13.25/computer/year. Approximately $60,000/year for Kansas State University’s Campus
Lowers: =
*Calculation based on an estimated of 9 hours of standby at 8 cents/kWh and 4,495 networked computers on campus using data from Dell Optiplex 380 computers
Results
Future Work
Power consumption was found to be dependent on the computer age, computer hardware status and software in use. In all cases the Energy Star rated computers (Dell Optiplex 380) used less energy than then Dell GX520 (on average 52% less).
To truly utilize power saving software (such as Faronics PowerSave) to its full potential more research needs to be performed on settings. Some useful information to collect includes:
Explore when computers are being used most. Look at first login and last logout times. Are there certain times (such as nights and weekends) when more aggressive power saving settings should be implemented?
Log how often computers are being used and how often they are sitting idle. Include how long between logins and logouts.
User profile for computers, done for different labs on campus as well as different times of the year, related to beginning of semester versus end of semester, and summer versus school year.
Literature Review
With computers energy usage responsible for g of CO2 emissions in an hour and using watts each[1], finding ways to save energy on computers could have both monetary savings as well as help the environment.
The IT industry is responsible for 2% of global CO2 emissions.[1]
Power management could half the IT industry’s emissions.[1]
60% of desktop PCs in commercial buildings are left fully powered on during nights and weekends.[2]
An estimated 5% of each electricity bill is wasted by inactive electronics.[3]
Huge energy savings could be realized by using more efficient machines and implementing power management techniques.
Power factor also varied dependent on the type of computer and the activity being done on it.
Table 1: Power Consumption of different computers on campus
Computer On [W]
Computer Standby Mode [W]
Dell Optiplex 360
48.80
1.32
Dell Optiplex 380
35.73
1.33
Dell Optiplex 745
50.51
1.67
Dell Optplex 760
80.82
2.63
Dell GX520
84.12
1.50
The Energy Star rated OptiPlex 380 was found to use the least amount of power when compared to other computers on campus, as shown in the table to the right.
References
[1] Sheehan, Mark C., and Shannon D. Smith. Powering Down: Green IT in Higher Education. ECAR Research Study 2, 2010.
[2] Gunaratne, Chamara, Ken Christensen, and Bruce Nordman. "Managing energy consumption costs in desktop PCs and LAN switches with proxying, split TCP connections, and scaling of link speed." International Journal of Network Management (2005). Web.
[3] Keltner, Susan. "Its Getting Hot: University of South Carolina Students' Electricity Use, Attitudes Toward Climate Change, and Subsequent Savings in Electricity and Averted Emissions that can Result the Promotion of Energy Efficient Behaviors and Infrastructure Improvements." Miami University Thesis
[4] Watts Up meter. CableOrganizer.com. N.p., Web. 4 Aug
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Acknowledgements
Special Thanks to: the National Science Foundation Award EEC , Ernie Perez, Rebecca Gould, Nicholas Brown, Bill Kuhn, Casey Lauer, and the ITAC department at Kansas State University