good practices in the use of ict equipment for electricity savings at a university campus

Recommended Practices in the Use of ICT Equipment for Energy Savings

Andreas Kamilaris, Dang Truong Hoang Ngan, Alexandros Pantazaras, Balaji Kalluri, Sekhar Kondepudi and Tham Kwok Wai

Dallas, TX : Nov 3-5 2014

Green ICT :

Importance of ICT Loads

2 © 2014 Sekhar Kondepudi

MELs (Miscellaneous Electric Loads)

MELs account for more than 20% of the primary energy used in commercial buildings and this is expected to rise to 40% by 2035.

MELs are transforming into dominant electrical loads

As can be seen the electrical loads by traditional uses is expected to decline, while the same for MELs is increasing rapidly.


Motivation

• A study measuring consumption of MELs in a controlled environment in University of California in San Diego revealed that MELs category of ICT equipment accounts for:

–70% of the electrical loads during peak hours

–80% of the electrical loads during off-peak hours

• Therefore energy audit focusing on ICT equipment is very important, when minimizing the energy foot-print of a building.


Questions - Typical ICT Devices in an Office Building

• What are the different power (plug load) behaviors of different ICT devices ?• What are the different ICT device classes ?• Can these plug loads and their related parameters be characterized ?• What is the transient behavior of these devices – moving from one state to

another?• Are there similar patterns within a device class?• How to manage increasing ICT loads in next-gen smart buildings ?• Can we develop Predictive Algorithms for Disaggregating Multiple Loads from a

Single Measurement


Goal & Approach

• Goal–To develop Best Practices on the Use of ICT Devices in the University Campus using the School of Design & Environment (SDE) as a proxy (3 Departments, 3 Buildings)

• Quantitative–Detailed Inventory of ICT Devices

–Measurement of Individual ICT Devices

–Field Measurements & Monitoring

• Qualitative–Surveys and interviews with users and facility managers


Inventory : 225 rooms with 1,534 ICT devices

• Desktop PCs + Displays = 1300

• Imaging (Printers, Scanners, MFD) = 150

• VoIP Phones = 85

• Projectors = 44;

• Faculty offices = 108, predominantly in SDE1-L4&L5 then in SDE3-L2&L3

• Admin Staff = 104, predominantly in SDE1-L3&L5 then in SDE2-L1&L2

• Limited Laptops – Not permanently attached ( only 5 )

• Desktops: 41%• Display Monitors: 41%• Imaging equipment: 8%• VoIP, projectors, external LCD screens:10%


Measurements

• Energy Metering HardwareEmployed smart power outlets or smart plugs to sandwiched in the middle of the socket and electrical appliance plug to measure their consumption. • These motes sample the current, voltage, active and apparent power of the

attached load.

• They include a low-power processor, radio and integrated antenna.

• Developed drivers in Java for parsing the measurements and storing them in a database for statistical analysis, similar to smart homes concept.


ICT Devices Sample Test Matrix

Monitor Projector Printer Desktop Laptop

ON-Low Brightness OFF OFF OFF OFF

ON-Med Brightness SLEEP OFF – BOOT UP – IDLE OFF to ON OFF to ON

ON-High Brightness ON IDLE – PRINT – IDLE (6 Single sided) ON ON

STANDBY SLEEP TO ON IDLE – PRINT – IDLE (3 double-sided) ON-app ON-app

OFF ON TO SLEEP IDLE – SCAN – IDLE (3 page) ON to SLEEP ON to SLEEP

IDLE – COPY – IDLE (6 single-sided) ON-app to SLEEP ON-app to SLEEP

IDLE – COPY – IDLE (3 double-sided) SLEEP SLEEP

SLEEP - IDLE SLEEP-app SLEEP-app

IDLE SLEEP to ON SLEEP to ON

SLEEP SLEEP-app to ON SLEEP-app to ON

ON to HIBERNATE ON to HIBERNATE

ON-app to HIBERNATE ON-app to HIBERNATE

HIBERNATE HIBERNATE

HIBERNATE-app HIBERNATE-app

HIBERNATE to ON HIBERNATE to ON

HIBERNATE-app to ON HIBERNATE-app to ON

ON to OFF ON to OFF

ON-app to OFF ON-app to OFF

CHARGING9 © 2014 Sekhar

Kondepudi

Field Deployment ( Faculty Offices)

• Desktops

• Laptops

• Monitors

• Printers

• Scanners

• MFDs

• VoIP Phones


Some Average Measurements


Desktops Transient Power Behavior (From Hibernate, Sleep, Off ) to ON

0 10 20 30 40 50 60 70 80 90 100 110 1200.00

20.0040.0060.0080.00

100.00120.00140.00160.00180.00200.00

Active Power vs TimeDesktop 1 Desktop 2 Desktop 3

Time (sec)

Activ

e Po

wer

(W)

SLEEP to ON

0 10 20 30 40 50 60 70 80 90 100 110 120 130 1400.00

20.0040.0060.0080.00

100.00120.00140.00160.00180.00200.00220.00240.00


Time (sec)

Activ

e Po

wer

(W

)

HIBERNATE to ON

0 10 20 30 40 50 60 70 80 90 100 110 1200.00

20.0040.0060.0080.00

100.00120.00140.00160.00180.00200.00220.00


Time (sec)

Activ

e Po

wer

(W)

OFF to ON


Desktop Transient Current Draw

0 20 40 60 80 100 1200.000.100.200.300.400.500.600.700.800.90

Current vs TimeDesktop 1 Desktop 2 Desktop 3

Time (sec)

Curr

ent (

A)

SLEEP to ON

0 50 100 150 200 2500.000.050.100.150.200.250.300.350.400.450.50


Time (sec)

Curr

ent (

A)

HIBERNATE to ON

0 10 20 30 40 50 60 70 80 90 100 110 1200.00

0.10

0.20

0.30

0.40

0.50

0.60


Time

Curr

ent

OFF to ON

13© 2014 Sekhar Kondepudi

MFD Printers (Desktop, Monochrome)

0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.000.00

100.00200.00300.00400.00500.00600.00700.00

Printer (MFD) - Idle State

Printer 1 Printer 2

Time (sec)

Pow

er (W

att)

5000 5200 5400 5600 5800 6000 6200 6400 6600 6800 70000

10

20

30

40

50

60

70


Time (sec)

Aver

age

Pow

er (W

)

Spike every 40 seconds (keep the drum warm ?)Spike lasts for 7-8 secondsConsumes up to 500W during that small timeframeTrend similar with Other MFD printer

Snapshot of Field Data Captured at 15 sec intervals over multiple weeksRange between 50 and 60 W Energy Consumption Consistent with Detailed Per Second Data

Assume 50 W for 12 hours a day X 365 Days X $ 0.25 / Kwh ~ $ 55.00 / year / printer At least 3000 such printers on NUS Campus = $ 165,000 savings annually


Good Practice : Use Laptops over Desktops

• Laptops consuming 25% less power than desktops in ON mode and 50% less power during SLEEP mode.

• Our measurements show heat produced by desktops is 4 times more than laptops. Each laptop needs 3000 btuh less than a desktop to cool office space.

• Recommendation to procure Laptops when refresh time comes for computers


Popular Approaches for the Power Management of Desktops

• Wake-on-LAN : send packets on network to make machines sleep on wake up depending on network activity.

• SleepServer : transition to low-power sleep while maintaining network presence of all connected machines by a proxy mechanism on one server.

• LiteGreen : virtualize the desktop environment, migrating it between the user’s physical machine and virtual server.


Good Practice : Power Management of Desktops (1)

• Assigning power settings, more suited to the intended use of the computing devices.

• Many users of our building were not sure whether they should set their laptop in hibernate or sleep mode when they had to leave for lunch or home.

• When ON, consumption is 34 times more than in SLEEP and 116 times more than HIBERNATE.

• SLEEP consumes more power than HIBERNATE but enables a faster waking up time of the desktop. However the difference is quite tolerable • 20-65 sec, 0.46 Watts in Sleep and 40-80 sec, 0.08 Watts in Hibernate


Good Practice : Power Management of Desktops (2)Sleep vs. Hibernate

• Laptop Running NO applications. For less than 44 minutes and 30 seconds, it is better that a laptop is in SLEEP. For longer, hibernate is preferred.

Running applications. For less than 59 minutes and 39 seconds, it is better that a laptop is in SLEEP. For longer, hibernate is preferred.

• DesktopsThe tradeoff (independent of running applications or not) is 126 minutes and 3 seconds. Less than this time, it is better to put the desktop to SLEEP. More than this time, it is more practical to HIBERNATE.

Dilemma – Due to a large trade off of over two hours, the user is better off switching the desktop OFF when leaving it idle for over two hours.


SLEEP and OFF have nearly the same power consumption.

Hence switch off monitor, whenever a user puts their desktop in SLEEP.

Power consumed in IDLE is 15-22 times more than SLEEP.

Hence, set time to switch off display after 15 or so minutes of inactivity.

Good Practice: Power Management of Display


Good Practice: Brightness of Display

Adjusting brightness to 75% can lead to 18% decrease in consumption

Adjusting to 50%can lead to 30% savings.

Recommendation: 65%-85% brightness do not affect productivity while saving electricity.


Good Practice : Switch Printers OFF at night

• Common Printers & Multifunctional Devices (MFDs) in labs as well as those in the personal spaces of academic staff, remain IDLE/ SLEEP at night time.

• Especially at Night, there is no need to have the printers/ MFDs ready for tasks so these devices should be powered off, after hours.

0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.000.00

100.00200.00300.00400.00500.00600.00700.00


Printer 1 Printer 2

Time (sec)

Pow

er (W

att)

Between $ 50 and $ 75 savings per printer per year


Good Practice : Single vs. Double Sided Printing

• Is double sided printing is more efficient compared , to single sided (in addition to the savings of paper ?

• YES – Always better to print double sided

Single-sided printing consumes 2.13 times more power than double sided.

0.124 Kwh for 3 double-sided pages compared to 0.058 Kwh for 6 single-sided pages.


MFD Double sided Copying

Time: 54 sec, Power: 0.209kWh Single Sided Copying

Time: 34 sec, Power: 0.117 kWh

Single-sided copying consumes 1.8 times less power than double-sided copying.

Hence, with regards to electrical energy savings, it is better to copy single-sided.

But there is a trade-off here, as single-sided copying uses more paper.

Good Practice : Single vs. Double Sided Copying


Good Practice : Scan+Email vs. Copy

• Is it better to Scan + Email or make a Physical Copy ?

• YES – Always better to Scan + Email : Energy + Paper savings

Sample of 6 pages scanned vs. 3 double-sided copies.

Copying needs 9 times more energy and 3 times more time.


Projectors have highest power consumption compared to other ICT devices. The projectors we tested consumes 220-285 Watts

SLEEP mode: Power: 10-12 Watts. Time to start up from SLEEP: 29 sec

OFF mode: Power: 0 Watts. Time to start up from OFF: 56 sec

Hence it is preferred to switch project OFF, as the 27 seconds saved in time, are not much compared to the gain in energy savings.

Projector Power consumption is directly linked to the brightness. Therefore it is suggested that only the needed LUMENS specifications must be installed.

Good Practice : Switching OFF projectors


We compared energy efficiency of an Energy Star labeled laptop and a non-labeled Laptop in both IDLE and SLEEP modes.

Energy Star Labeled Laptop consumes 43% less power than a non-labeled Laptop in

IDLE mode. 14% less power than a non-labeled Laptop in

SLEEP mode.

Hence, we strongly suggest to purchase Energy Star labeled ICT devices

Good Practice : Energy Star Equipment


Power consumption of VoIP phones is very low around 2.5 Watts for a VoIP.

Incoming or outgoing calls do not have an impact on the consumption of power.

1 9 17 25 33 41 49 57 65 73 81 89 97 105 113 121 129 137 1450

0.5

1

1.5

2

2.5

3

3.5

VoIP IDLE

VoIP CALL OUT

VoIP CALL IN

Time (seconds)

Po

we

r (W

att

s)

Even though VoIP usage is low, the phones consume power at night time when they are mostly idle.

Cisco has introduced an Energy-Wise feature, having the ability to turn the VoIP phone off and on based on the loads on the local network.

Good Practice : Energy Wise-Featured VoIP Phones


Good Practices particularly for University Campuses


An underestimated energy savings parameter is efficient and accurate utilization of common PC labs.

In SDE, during class in PC Lab time, the PC utilization is more aggressive, reaching 68%. This is still less to warrant a fully provisioned lab.

9:00 9:30 10:0010:3011:0011:3012:0012:3013:0013:3014:0014:3015:0015:3016:0016:3017:0017:3018:0018:3019:000

10

20

30

40

50

60

70

80Tuesday Thursday

Friday

Day Time

Oc

cu

pa

nc

y (

%)

Good Practice : Better Utilization of Common PC Labs

29

Class timings for the chart below:Tuesday 1100-1300, Thursday 1000 -1400

© 2014 Sekhar Kondepudi

Need to have Better Utilization of Common PC Labs

• Students use different machines each time.

• Students forget to switch them off after each use.

• 22% of the machines remain idle after use.

• 51% of the machines remain idle after use after a class. ON SLEEP OFF

0

10

20

30

40

50

60

70

Class No Class

Desktop State

Pe

rce

nta

ge

(%

)



Educate students about the importance of saving energy by switching off the machines after use.

A Supervisor from students or staff, should make sure machines are switched off.

Differentiate general computing labs with PCs to specialized computing lab with PCs.

Specialized labs should only house as many students as course registration.

Generalized lab may offer just basic computing facilities to a larger student body.



Some desktops in common pc labs, run simulations for hours or even a few days.

Friday

Thursday

Wednesday

Tuesday

Monday

0 5 10 15 20 25 30

SIMULATION ON

SLEEP OFF

NIGHT

Consumption (kWh)

Desktops used for simulations consume largest percentage of electricity. More than 50% on all weekdays.

Increased consumption at night time, due to desktops running simulations. Left ON from previous day.

Good Practice : Select desktops used in simulations wisely


Estimations of Potential Savings

• Almost $ 50K per year in School of Design & Environment

• University Wide – probably can extrapolate to $ 500 – 750 K per year


In Summary

• Great Potential to implement Best Practices which not only save energy but also money. Win-Win

• Areas of future workAudit power consumption of ICT infrastructural devices

Increase the duration of the study for greater than 6 months to identify temporal patterns for saving.

Associate user groups/profiles with use of ICT devices and try to develop more effective and personalized strategies to encourage occupants to adopt greener use of office equipment.

• Still not clear whether to involve building users more for energy savings or use automation. We support at least some education and training which is essential for users to perceive how to use their ICT devices.


Prof. Sekhar Kondepudi, [email protected]+65 9856 6472

Dr. Andreas [email protected]

The authors would like to acknowledge the support of the Ministry of Education, Singapore. Via an AcRF Grant for this project

mailto:[email protected]

mailto:[email protected]

good practices in the use of ict equipment for electricity savings at a university campus

Technology

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sekhar kondepudi

idle print idle

idle copy idle

desktop pcs

idle scan idle

standby sleep

med brightness sleep