A Strategy for Energy Savings: Desktop/Laptop Computers
GENERAL GUIDELINES: Involve all stakeholders (desktop support, networking staff, information security, business contacts and users) in planning a solution for energy savings. Test your plan before communicating to staff. Consider implementing power management strategies for peripheral devices as well (printers, scanners, etc.) because significant energy savings are achievable.
DEVELOPING A BASELINE: Computer and monitor power-consumption rates are typically listed on equipment labels or in documentation that is included with the equipment. Your organization’s Clean Energy Future champion, working with your technology staff, should be able to estimate current power consumption from an inventory list or a sampling of computers and monitors. For example, the label on a desktop computer indicates it draws 5.0 amps at 120 volts. This is equal to 600 (5 x 120) watts of power per hour (P=E x I) where “P” is power, “E” is voltage and “I” is current in amps. The label on the LCD monitor in this example specifies that it draws 0.75 amps at 120 volts, about 90 watts per hour. Therefore, the total power used by this computer/monitor is 690 watts per hour or 16,560 watts (16.56 kilowatts) over 24 hours when operating (always on, inactive sleep/hibernation). If this computer is in use for 10 hours a day (turned off overnight) it is consuming 6.9 kilowatt-hours of electricity per day. One option for recording this information is a simple spreadsheet that lists each configuration and the manufacturer’s indication of power consumption; the number of units of each configuration; and the number of hours that the unit is in operation on an average workday. The list should also indicate whether power management is enabled. With this information, your organization should be able to determine how much energy your computers and monitors are using on a daily (24-hour) basis. This will be your baseline, which your Clean Energy Future champion should relay to oet.isrm@state.mn.us.
SOME QUESTIONS TO CONSIDER: 1. How does your agency handle power management today? Is your staff currently shutting down PCs at the end of each day or over the weekend? Are you already using computerized power management (CPM)? Think about why you are doing things the way you are, and what led you to that decision. Those considerations should be at the table in discussing your strategy/program.
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2. What are your standard and extended hours of operation? What impact would a systematic power management solution have on your business operations? You should plan a solution that does not negatively affect staff during standard hours, but that also has minimal impact on those who conduct business during extended hours. 3. How big is your organization? How many locations and network segments? In smaller organizations, it may be easier to educate staff to take steps (powering off PCs at night, for instance) to change behavior. A distributed environment may be more challenging in terms of using automated tools, so you may want to have staff in smaller offices take manual steps to shutdown PCs. Remote locations may conduct business differently than your central locations, so you should involve them in identifying a workable solution. 4. Do you have desktop computing jobs that run overnight? If any staff within your organization needs to run jobs at night, you will need to consider the impact that CPM and/or powering off computers may have on those jobs, and identify a strategy to exclude those computers from your shutdown/power management method. 5. Do you have maintenance jobs or IT-related activity that takes place over the weekend? If not, one action that can save energy as a quick first step is to ask staff to shut down PCs when they leave the office Friday. 6. Do you own a systems management tool? Can it “wake” PC’s and/or shut them down? If so, you can consider using the tool to turn off PCs when you want them powered off and wake them when they need to be powered on. You should work with your information security and networking team to ensure that any implementation of “Wake-on-LAN” capability is secure. If you do not have a systems management tool, there are alternative tools and methods for turning off and waking PCs. The Office of Enterprise Technology (OET) IT Standards and Resource Management (ISRM) office will seek to identify recommended tools – if you need help, contact ISRM at oet.isrm@state.mn.us. 7. Do you have maintenance jobs (Microsoft patches, virus scans, software distributions) that happen at night or on the weekend? If so, you will need to ensure that PCs are available to process those jobs. You should test the impact of computer power management on all maintenance jobs to ensure that CPM doesn’t prevent a scheduled weekly virus scan to execute properly). 8. Do you have computers that connect remotely (from an employee’s home, etc.)? If you implement an automated shutdown solution, be sure to consider the impact on equipment (laptops, etc.) used remotely. For instance, a staff person working at home on a laptop may be adversely impacted if a shutdown is implemented across the board. You may want to seek solutions that only affect PCs within your offices and don’t affect those working remotely.
For additional guidance, or if you have questions, please e-mail oet.isrm@state.mn.us.
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