This web conference, led by the New Buildings Institute and Ecova, presented the results of the commercial office plug load field monitoring study conducted on behalf of the California Energy Commission’s Public Interest Energy Research (PIER) program. The study, completed in July 2011, characterized the energy consumption of plug load devices in commercial applications and explored opportunities for plug load energy savings.
For more information: www.esource.com/PIER
Office Plug Loads: Energy Use and Savings Opportunities
1. 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
2. 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
4. Topics
NBI:
• Definitions & Trends
• Key Performance
Indicators
• Measured Results
Examples
Ecova:
• Field Research
• Office Equipment
Energy Use
• Savings Opportunities
• Programs / Policy
4
5. 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
5
6. Plug Loads: not hard wired, not in other end use
categories AND not regulated by building energy codes
Office Equipment: White Goods & Other:
Computers & monitors Vending machines
Small power supplies Large coffee
Speakers machines
Printers Water coolers (!!)
Copiers and MFDs Large refrigerators
Faxes Other appliances
Scanners and multi-function Space heaters
devices (MFDs) Task lighting
“I-Items” (chargers, phones,
Ipads,etc.)
SERVERS!!!
Modified from Sabo, NYSERDA Power Mgmt. Program. 6
7. Plug loads are One of the Largest and Fastest Growing
End-Uses of the Residential and Commercial Sectors
Source: Graph created by Ecova with data from EIA 2008 Annual Energy Outlook
7
8. % of Whole Building Energy – interesting
but deceptive
• Office equip., computers and 'other'
CBECS • All commercial bldgs – 20%
• All non-mall bldgs - 12%
• Office equip., misc. equip.
CEUS • All commercial bldgs – 13%
• All offices – 23%
• Small Oakland office all plug loads – 30%
• Small Oakland office plugs without server closet –
PIER 8%
• 2003 Impact Assessment Office Equipment – 6%
8
10. Watts per square foot (W/SF) – Offices
power density* is a key performance indicator (KPI)
Plug Load Performance Level
Poor Standard High Perf Best
Occupied Power Density W/SF 0.75 + 0.75 0.40 0.25
Peak Demand Density W/SF 1.5 + 1.5 1 0.75
nbi Sensitivity Analysis and PIER monitoring
“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 10
11. KPI: 24 hour Schedule
Plug Load Power Density (W/SF)
11
15. Plug Load Power Density
Measured Performance (W/SF)
Office Location: Size Average Average Measured % of total
(SF) Weekday Weekday Peak at night
Daytime 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
15
16. Plug Load Power Density versus
Lighting Power Density (W/SF)
Average Plug Load
Average
Weekday Power vs.
Office Location: Size (SF) Weekday
Daytime Efficient
Daytime Plugs
Lighting Lighting
Irvine, CA 1 8,328 0.8 0.2 4x
Irvine, CA 2 1,500 0.8 0.4 2x
Rosemead, CA 16,500 0.5 0.5 equal
Los Angeles, CA 8,024 1.5 0.3 5x
Vancouver, BC 9,000 0.6 0.5 1.2 x
Source: nbi Office of the Future Pilot
Project Monitoring
16
17. 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
17
19. total energy and sustainability management
MEASURED PLUG LOAD ENERGY SAVINGS IN
TWO CALIFORNIA COMMERCIAL BUILDINGS
By Chris Calwell and Catherine Mercier
January 26, 2012
19
20. Value: Growing Results on Saving Resources
Total Energy & Sustainability Management
See More Save More Sustain More
Gain broad visibility Lower expenses & Build lasting
and precise insight increase return on advantages for the
into inefficiencies capital investments bottom line and the
environment
Data-driven + Fully managed + Technology-optimized
20
22. 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.
22
23. 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
23
24. 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)
24
25. 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
25
26. 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
26
30. PLUG LOAD ENERGY USE
Device energy Avg. device Total # of devices
= energy use from X
use inventoried
metering
Total plug load energy use = Sum of the energy use of all devices
30
31. 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?
31
32. PLUG LOAD ELECTRICITY USE AT TWO
CALIFORNIA OFFICES
Which plug loads use the most energy?
1%
Misc.
11% 5%
Imaging Misc.
Equip.
17%
Imaging
Equip. and
Computer
20% Peripherals
Monitors
9%
Monitors
69%
Computers
68%
Computers
Library Small Office
Plug load Electricity Use Breakdown Plug load Electricity Use Breakdown
Total= 66,300 kWh/yr (0.7 kWh/ft2) Total=13,100 kWh/yr (0.94 kWh /ft2)
32
33. 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.
33
34. 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
34
35. 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.
35
36. DRAWING POWER WHEN INACTIVE
Power meter data of a printer, calculator and computer speakers
at the small office
36
37. 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.
37
38. POWER USE SHOULD BE PROPORTIONAL TO
UTILIZATION
Actual
Power
Best
0% Workload, functionality, or useful output 100%
38
39. 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
39
40. Low- and no-cost strategies could save 40% of
AT THE SMALL OFFICE
studied plug load energy use
40
41. Low- and no-cost strategies could save 19% of
AT THE LIBRARY
studied plug load energy use
41
42. POWER MANAGEMENT: DESKTOP COMPUTER
Base case: 356 kWh/year
Improved case: 153 kWh/year
400
Energy reduction = 202 kWh/year (57%)
350
Annual Energy Consumption (kWh)
300 -57%
250
No
200 Power
Mgmt.
150
With
100 Power
Mgmt.
50
0
42
43. MINI COMPUTER + POWER MANAGEMENT
= 95% SAVINGS
Other benefits: less desk or floor space, quieter, and create less
waste heat
Office desktop computer:
rarely used but always on
Replaced with mini computer
with power management enabled
43
44. MINI COMPUTER + POWER MANAGEMENT =
95% SAVINGS
No
Power
Mgmt.
44
45. MINI COMPUTERS WITH BASIC FUNCTIONALITY AND
ULTRA-LOW POWER USE
Idle: 7.7 W
Idle: 8.0 W
45
46. LOAD-SENSOR PLUG STRIP ENERGY SAVINGS:
OFFICE WORKSTATION
Base case: 114 kWh/year
Improved case: 61 kWh/year
120 Energy reduction: 52 kWh/year (46%)
100 Computer Speakers
Annual Energy Consumption (kWh)
-46%
Laser Printer
80
Computer Monitor
60 -79%
-77%
40
-7%
20
0
BASELINE CASE IMPROVED CASE - LOAD-SENSOR PLUG
STRIP
46
47. TIMER PLUG STRIP: WORKSTATION
AT THE SMALL OFFICE
Base case: 375 kWh/year
Improved case: 214 kWh/year
400 Energy reduction = 161 kWh/year (43%)
375
350 Computer Speakers
325 Calculating Machine
Annual Energy Consumption (kWh)
300 -43%
275 Computer Monitor
250 Laser Printer
225 -65%
200 -65%
175
0%
150
125
100
-48%
75
50
25
0
BASELINE CASE IMPROVED CASE - TIMER PLUG STRIP
Small Office
47
48. 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
48
49. 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
49
50. 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?
50
51. 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
51
54. 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
54
56. 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.
56
57. A SAMPLE OF A PROXY INSTALLED IN A
COMPUTER’S NETWORK INTERFACE CARD
Source: B. Nordman, LBNL
57
63. 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.
63
64. 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
64
65. New work…
Office Plug Loads:
Best Practice Guideline
Others Others
66. Questions?
Download the
Executive Summary and
Full Report
Learn more:
www.ecova.com
www.newbuildings.org