Office Plug Loads: Energy Use and

Savings Opportunities Sponsored by the California Energy Commission

Public Interest Energy Research Program

David Weightman, Energy Commission Specialist California Energy Commission dweightm@energy.state.ca.us

Jenny Field, Marketing Manager

E Source jenny_field@esource.com

Thursday, January 26, 2012

Our Presenters

Cathy Higgins Program Director New Buildings Institute

Amy Cortese Renbarger Senior Project Manager New Buildings Institute

Catherine Mercier Project Lead, Policy and Research Ecova

Chris Calwell Senior Fellow, Policy and Research Ecova

Cathy Higgins - higgins@newbuildings.org

Topics

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NBI: • Definitions & Trends • Key Performance

Indicators • Measured Results

Examples Ecova: • Field Research • Office Equipment

Energy Use • Savings Opportunities • Programs / Policy

New Buildings Institute (nbi)

• National non-profit, offices in WA

• Board of Directors represent leaders in energy and green building

• Sponsors include progressive utilities, PBAs, market transformation entities and state governments

• Strategic relationships with leading organizations including AIA, USGBC, WCEC, CLTC, CPUC, CEC

• Strong staff of leading technical experts and project managers

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Office Equipment:

Computers & monitors Small power supplies Speakers Printers Copiers and MFDs Faxes Scanners and multi-function devices (MFDs) “I-Items” (chargers, phones, Ipads,etc.)

White Goods & Other: Vending machines Large coffee machines Water coolers (!!) Large refrigerators Other appliances Space heaters Task lighting SERVERS!!!

Plug Loads: not hard wired, not in other end use categories AND not regulated by building energy codes

6 Modified from Sabo, NYSERDA Power Mgmt. Program.

Plug loads are One of the Largest and Fastest Growing End-Uses of the Residential and Commercial Sectors

7 Source: Graph created by Ecova with data from EIA 2008 Annual Energy Outlook

% of Whole Building Energy – interesting but deceptive

8

• Office equip., computers and 'other' • All commercial bldgs – 20% • All non-mall bldgs - 12%

CBECS

• Office equip., misc. equip. • All commercial bldgs – 13% • All offices – 23%

CEUS

• Small Oakland office all plug loads – 30% • Small Oakland office plugs without server closet –

8% • 2003 Impact Assessment Office Equipment – 6%

PIER

Energy use trends

9

Watts per square foot (W/SF) – Offices power density* is a key performance indicator (KPI)

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“It is now possible to realistically conceive of an office space that could have a peak plug load as low as 0.25 W/SF”

Wilkins, Hosni, “Plug Load Factors” ASHRAE Journal May 2011

*also called load factor

Poor Standard High Perf BestOccupied Power Density W/SF 0.75 + 0.75 0.40 0.25

Peak Demand Density W/SF 1.5 + 1.5 1 0.75nbi Sensitivity Analysis and PIER monitoring

Plug Load Performance Level

KPI: 24 hour Schedule Plug Load Power Density (W/SF)

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Schedule of Use as a KPI – Plugs & Lights

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Plug Loads – Field Examples

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Amy Cortese Renbarger - amy@newbuildings.org

Plug Loads at Tenant Spaces

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Plug Load Power Density Measured Performance (W/SF)

Office Location: Size (SF)

Average Weekday Daytime

Average Weekday

Night

Measured Peak

% of total at night

Irvine, CA 1 8,328 0.8 0.4 1.6 47%

Irvine, CA 2 1,500 0.8 0.6 1.8 70%

Rosemead, CA 16,500 0.5 0.3 0.7 63%

Los Angeles, CA 8,024 1.5 1.46 2.1 97%

Vancouver, BC 9,000 0.6 0.3 0.8 49%

Source: nbi Office of the Future Pilot Project Monitoring

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Plug Load Power Density versus Lighting Power Density (W/SF)

Office Location: Size (SF) Average

Weekday Daytime Plugs

Average Weekday Daytime Lighting

Plug Load Power vs. Efficient Lighting

Irvine, CA 1 8,328 0.8 0.2 4 x

Irvine, CA 2 1,500 0.8 0.4 2 x

Rosemead, CA 16,500 0.5 0.5 equal

Los Angeles, CA 8,024 1.5 0.3 5 x

Vancouver, BC 9,000 0.6 0.5 1.2 x

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Source: nbi Office of the Future Pilot Project Monitoring

Plug Load Points

• Plug loads in offices are now many times larger than efficient lighting loads – program focus needed

• Even in the “best” offices, plug load use in the Unoccupied periods is at least 50% of the Occupied periods

• Watts per SF and ratio of night-to-day energy use are KPIs

• Differentiate servers from other plug loads and use consistent definitions and metrics

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Q&A for nbi

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total energy and sustainability management

MEASURED PLUG LOAD ENERGY SAVINGS IN TWO CALIFORNIA COMMERCIAL BUILDINGS

By Chris Calwell and Catherine Mercier January 26, 2012

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Value: Growing Results on Saving Resources Total Energy & Sustainability Management

Data-driven + Fully managed + Technology-optimized

See More See More Save More Sustain More

Gain broad visibility and precise insight into inefficiencies

Lower expenses & increase return on capital investments

Build lasting advantages for the bottom line and the

environment

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Credentials: An Extension of More Businesses •$18B in expenditures •450,000 sites

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ACKNOWLEDGMENT • Our funding

The report was prepared with the support of the California Energy Commission’s Public Interest Energy Research (PIER) Program.

• Our team • Catherine Mercier, Ecova • Laura Moorefield, Ecova • Chris Calwell, Ecova • Craig Billingsley, Ecova • Cathy Turner, New Buildings Institute • Cathy Higgins, New Buildings Institute • Dan Harris, New Buildings Institute • Lia Webster, Portland Energy Conservation, Inc. • Erin Rowe, Portland Energy Conservation, Inc. • Eric Greensfelder, Portland Energy Conservation, Inc. • Mark Effinger, Portland Energy Conservation, Inc.

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SUMMARY

• Plug loads are becoming an increasingly large share of commercial building energy use

• New LEED-certified buildings point the way to extraordinary energy savings potential, yet even buildings that are otherwise very efficient can fail to meet energy use projections if the plug loads installed in them are inefficient and occupant behaviors remain unchanged

• Even LEED-certified buildings can significantly reduce their plug load energy use through a variety of strategies

• Need more comprehensive and ambitious policy action

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PRESENTATION OUTLINE

• Study objectives and methodology (Cat Mercier) • Key study results (Cat Mercier)

• Plug load electricity consumption in two California offices • Savings opportunities and measures • Summary of plug load energy savings at the two site

• How can policy and utility program approaches best address these opportunities? (Chris Calwell)

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STUDY OBJECTIVES

• Characterize electricity consumption of plug load devices in two recently LEED-certified buildings in California

• Explore opportunities for plug load energy savings in these two buildings

• Test a variety of hardware, software and occupant behavior energy reduction strategies

• If the above energy reduction strategies are successful, identify actions that utilities and policy makers could take to secure these savings throughout California’s commercial buildings

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TWO NORTHERN CALIFORNIA SITES SELECTED • LEED Gold public library (95,000 ft2)

• 48 employees, open 52 hours per week • Includes private offices and a public area; both areas were monitored

• LEED Platinum small office building (14,000ft2) • 20 employees • Typically occupied 60 hours per week

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STUDY METHODOLOGY AND SCOPE

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OUR METERS RECORDED TIME SERIES DATA ON INDIVIDUAL DEVICES At intervals of one minute for one month

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SAMPLE METER FILE FROM FIELD STUDY

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PLUG LOAD ENERGY USE

Total plug load energy use Sum of the energy use of all devices

Device energy use

Avg. device energy use from

metering = X Total # of devices

inventoried

=

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PRESENTATION OUTLINE

• Study objectives and methodology • Study results

• Plug load electricity consumption in two California offices • Savings opportunities and measures • Summary of plug load energy savings at the two site

• How can policy approaches best address these opportunities?

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PLUG LOAD ELECTRICITY USE AT TWO CALIFORNIA OFFICES Which plug loads use the most energy?

Library Plug load Electricity Use Breakdown Total= 66,300 kWh/yr (0.7 kWh/ft2)

Small Office Plug load Electricity Use Breakdown Total=13,100 kWh/yr (0.94 kWh /ft2)

68% Computers

69% Computers

5% Misc.

17% Imaging Equip. and Computer Peripherals

11% Imaging Equip.

9% Monitors

20% Monitors

1% Misc.

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KEY OPPORTUNITIES FOR ENERGY SAVINGS 1) 62% of desktop computers at the small office and 40% of staff

(non-public) computers at the library were often left operating in active or idle mode overnight and on weekends.

2) Printers and multifunction devices were used rarely, but drew 6 to 51 W when not in use.

3) Most computer peripherals metered, such as computer speakers, used power continuously when not in use.

4) Most LCD computer monitors, desktop computers and imaging equipment metered drew high active power compared with high-efficiency models available today.

5) Some imaging equipment and miscellaneous plug loads such as projectors and the solid ink printer were not very numerous, but each device consumed a significant amount of energy and did not appear to scale power consumption effectively to usage.

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MOST OF TIME WHEN IDLE, COULD BE ASLEEP Power meter data of a desktop computer at the small office

§ Small amount of time in active mode

§ Lots of time in idle mode at night and on weekends

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KEY OPPORTUNITIES FOR ENERGY SAVINGS 1) 62% of desktop computers at the small office and 40% of staff

(non-public) computers at the library were often left operating in active or idle mode overnight and on weekends.

2) Printers and multifunction devices were used rarely, but drew 6 to 51 W when not in use.

3) Most computer peripherals metered, such as computer speakers, used power continuously when not in use.

4) Most LCD computer monitors, desktop computers and imaging equipment metered drew high active power compared with high-efficiency models available today.

5) Some imaging equipment and miscellaneous plug loads such as projectors and the solid ink printer were not very numerous, but each device consumed a significant amount of energy and did not appear to scale power consumption effectively to usage.

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DRAWING POWER WHEN INACTIVE Power meter data of a printer, calculator and computer speakers at the small office

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KEY OPPORTUNITIES FOR ENERGY SAVINGS 1) 62% of desktop computers at the small office and 40% of staff

(non-public) computers at the library were often left operating in active or idle mode overnight and on weekends.

2) Printers and multifunction devices were used rarely, but drew 6 to 51 W when not in use.

3) Most computer peripherals metered, such as computer speakers, used power continuously when not in use.

4) Most LCD computer monitors, desktop computers and imaging equipment metered drew high active power compared with high-efficiency models available today.

5) Some imaging equipment and miscellaneous plug loads such as projectors and the solid ink printer were not very numerous, but each device consumed a significant amount of energy and did not appear to scale power consumption effectively to usage.

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POWER USE SHOULD BE PROPORTIONAL TO UTILIZATION

Pow

er

Workload, functionality, or useful output 0% 100%

Actual

Best

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KEY SAVINGS STRATEGIES

• Enable aggressive power management settings • PCs and imaging equipment • Largest opportunity

• Use load-sensor plug strips and timers to minimize off-hours energy use

• Adjust brightness settings of computer monitors • Occupant behavior measures

• Energy monitoring feedback devices • Outlook reminders to encourage office occupants to turn off devices when not in

use

• Highly efficient equipment • Shift from desktop computers to micro-sized desktops with basic

functionality and ultra-low power use when possible • Replace inefficient equipment with comparable, high-efficiency TopTen

models (http://www.toptenusa.org/) • Cost-effective at procurement cycle

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AT THE SMALL OFFICE Low- and no-cost strategies could save 40% of studied plug load energy use

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AT THE LIBRARY Low- and no-cost strategies could save 19% of studied plug load energy use

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POWER MANAGEMENT: DESKTOP COMPUTER

0

50

100

150

200

250

300

350

400

Annu

al En

ergy

Con

sum

ptio

n (k

Wh)

-57%

No

Power Mgmt.

With Power Mgmt.

Base case: 356 kWh/year Improved case: 153 kWh/year Energy reduction = 202 kWh/year (57%)

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MINI COMPUTER + POWER MANAGEMENT = 95% SAVINGS

Office desktop computer: rarely used but always on

Replaced with mini computer with power management enabled

Other benefits: less desk or floor space, quieter, and create less waste heat

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MINI COMPUTER + POWER MANAGEMENT = 95% SAVINGS

No

Power Mgmt.

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MINI COMPUTERS WITH BASIC FUNCTIONALITY AND ULTRA-LOW POWER USE

Idle: 7.7 W

Idle: 8.0 W

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LOAD-SENSOR PLUG STRIP ENERGY SAVINGS: OFFICE WORKSTATION

0

20

40

60

80

100

120

BASELINE CASE IMPROVED CASE - LOAD-SENSOR PLUG STRIP

Annu

al En

ergy

Con

sum

ptio

n (k

Wh) Computer Speakers

Laser Printer

Computer Monitor

-46%

-79%

-77%

-7%

Base case: 114 kWh/year Improved case: 61 kWh/year Energy reduction: 52 kWh/year (46%)

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TIMER PLUG STRIP: WORKSTATION AT THE SMALL OFFICE

0255075

100125150175200225250275300325350375400

BASELINE CASE IMPROVED CASE - TIMER PLUG STRIP

Small Office

Annu

al E

nerg

y Co

nsum

ptio

n (k

Wh)

Computer Speakers

Calculating Machine

Computer Monitor

Laser Printer

-43%

-65%

0%

-48%

-65%

Base case: 375 kWh/year Improved case: 214 kWh/year Energy reduction = 161 kWh/year (43%)

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FEEDBACK MONITORING DEVICE ENERGY SAVINGS: OFFICE WORKSTATION In the timeframe of this study it was not possible to prove that these savings would persist over time

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ENERGY SAVINGS OPPORTUNITIES: SMALL SERVER ROOMS • Excluded from previous plug load field metering studies • Can use more kWh than all other office plug loads combined • Ripe for more research • Large savings potential

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PRESENTATION OUTLINE

• Study objectives and methodology • Study results

• Plug load electricity consumption in two California offices • Savings opportunities and measures • Summary of plug load energy savings at the two site

• How can policy approaches best address these opportunities?

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HOW CAN POLICY AND PROGRAM APPROACHES BEST ADDRESS THESE OPPORTUNITIES? • Power management of existing equipment

• Network wide settings • Local settings under administrative control • Microsoft windows defaults not always maximizing savings

• After market hardware retrofits • Advanced plug strips and timers to control legacy equipment

• Procure more efficient office equipment • Network proxying for reducing energy consumption • Power scaling in energy efficiency specifications • Title 20 for office electronics • Plug load peak power density requirement in Title 24

• Aggressive education and awareness campaigns for staff about efficient behaviors and usage patterns

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ADVANCED PLUG STRIPS • Installing hardware control strategies to turn off devices when

they are not in use • Can reduce energy consumption significantly • This benefit must be weighed against the cost of purchasing and

installing these control strategies • Standby power : < 1 W • There is a need for a standardized test procedure • The Consumer Electronic/Plug Load Summit and the NEEP

Working Groups • Timers and timer plug strips

• Unnoticed by participants • Good options to control devices with regular schedules

• Load-sensor plug strips, automatically turn off power to devices when the current draw drops below a certain threshold • Savings ranged widely and depended on user’s behavior • Low-cost measure to eliminate the energy use of often-

forgotten computer peripherals at some workstations

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PROXYING FOR REDUCING ENERGY • Network standby energy use has become a big concern

internationally because so many devices that previously were able to sleep most of the time now remain awake and using energy 100% of the time because they are connected to networks.

• Networked devices maintain a steady, low level of communication with each other to verify that they are still on the network.

• Proxying involves a change to IT hardware design that allows a small, separate circuit to maintain the device’s connection to the network, without needing the primary CPU (and associated hardware) to operate.

• The proxying card or circuit wakes up the main device as needed to act on particular requests from the network, but otherwise allows it to sleep most of the time.

• The first IT products with this capability have been introduced over the last 18 months; more to follow with policy and program encouragement.

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A SAMPLE OF A PROXY INSTALLED IN A COMPUTER’S NETWORK INTERFACE CARD

Source: B. Nordman, LBNL

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POPULAR TASKS AND ASSOCIATED POWER USE

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POWER USE DURING NON-ACTIVE MODES

60 Source : IOUs Title 20 Efficiency Standards Workshop, August 2008

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Source : IOUs Title 20 Efficiency Standards Workshop, August 2008

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TOPTENUSA.ORG

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FUTURE RESEARCH NEEDS • Energy use of and savings opportunities for servers and server

closets • Savings potential from behavioral changes • Incremental cost of measures • Plug load demand impacts • Equipment and technology improvements • Continuous outreach and education efforts • Consistent plug load definitions for benchmarking • In order to provide adequate feedback to building occupants, the

wiring of commercial buildings needs to be done differently to meter key sub-systems.

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THANK YOU! Catherine Mercier Project lead, Research & Policy Ecova Durango, CO cmercier@ecova.com (970) 259-6801 ext. 311 Chris Calwell Senior fellow, Research & Policy Ecova Durango, CO ccalwell@ecova.com (970) 259-6801 ext. 301

New work…

Office Plug Loads: Best Practice Guideline

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Questions?

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