plug load efficiency for zero energy buildings webinar 1 29 2013

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

NREL’s Research Support Facility:Plug Load Efficiency Strategies in Meeting Net Zero Energy Goals

Shanti Pless, LEED APSenior Research Engineer

NREL Commercial Buildings Research Group

January 29, 2013

Innovation for Our Energy Future


http://www.nrel.gov/docs/fy11osti/51199.pdf2

Innovation for Our Energy Future3

NREL: 2006

Used with Permission from Haselden


Research Support Facility Vision

• A showcase for sustainable, high-performance designo Incorporates the best in energy efficiency, environmental performance,

and advanced controls using a “whole-building” integrated design process

• Serves as a model for cost-competitive, high-performance commercial buildings for the nation’s design construction, operation, and financing communities

Credit: RNL


NREL: Today

Used with Permission from Haselden


• More than 800 people in DOE office space on NREL’s campus• 220,000 ft2

• Design/build process withrequired energy goals • 25 kBtu/ft2

• 50% energy savings• LEED Platinum

• Replicable• Process • Technologies• Cost

• Site, source, carbon, cost ZEB:B• Includes plugs loads and datacenter

• Firm fixed price of ~$64 million• $259/ft2 construction cost (not including $27/ft2 for PV from PPA/ARRA)

• Open first phase June 10, 2010

DOE/NREL Research Support Facility: Project Goals

Cre

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Has

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onst

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Energy Efficiency Design Requirements

7

• 25 kBtu/ft2/yr for standard office space occupant density and data center loads

• Demand side energy use goal, not including renewables• Normalized up to 35.1 kBtu/ft2/yr for better space efficiency and to account for full data

center load

• On site renewables sized to offset site energy use to reach net zero annual use

Cre

dit:

Cha

d Lo

bato

/NR

EL

Old NREL/DOELeased Office

Building

Typical Denver Office Building

ENERGY STAR 75

Office Building

Average LEED Office Building

ENERGY STAR 90

Office Building

EPA Region 8 Of-fice

Denver, CO

RSF RSF Renewable Production

0

20

40

60

80

100

120

140

Site Mounted PVRoof Mounted PVData CenterWhole Building

An

nu

al

EU

I (k

Btu

/ft2

)

References:https://www.energystar.gov/index.cfm?c=new_bldg_design.bus_target_finderhttp://eere.buildinggreen.com/mtxview.cfm?CFID=46438782&CFTOKEN=31996638http://femp.buildinggreen.com/overview.cfm?ProjectID=864

https://www.energystar.gov/index.cfm?c=new_bldg_design.bus_target_finder

http://eere.buildinggreen.com/mtxview.cfm?CFID=46438782&CFTOKEN=31996638

http://femp.buildinggreen.com/overview.cfm?ProjectID=864


Key Design Strategies

• Optimal orientation and office space layout• Fully daylit office wings with high-

performance electrical lighting• Continuous insulation precast wall panels

with thermal mass• Operable windows for natural ventilation• Radiant heating and cooling• Outdoor air preheating

o Transpired solar collectoro Data Center waste heato Exhaust air heat recoveryo Crawl space thermal storage

• Aggressive plug load control strategies• Data Center outdoor air economizer with

hot aisle containment• Roof top- and parking lot-based PV


•100% of the workstations are daylit

•No employee more than 30 feet from a window

Daylighting


Daylighting: Glare Control

A light redirecting device reflects sunlight to the ceiling, creating an indirect lighting effect.

Fixed sunshades limit excess light and glare.

Credit: RNL


Reclaimed natural gas piping serves as support for the building.

The lobby and other common areas feature

beetle-kill pine from Western forests.

Daylighting reduces the need for the use of electrical lighting.

LEED Platinum rating, version 2.2 – 59 points.


Energy Modeling

End Use kBtu/ft2

Space Heating 8.58Space Cooling 0.85Pumps 0.48Ventilation Fans 1.88Domestic Hot Water 0.90Exterior Lights 0.12Lights 2.07Office Plug Loads 7.87Task Lights 0.10Data Center 12.11Data Center Cooling 0.02Data Center Fans 0.20

Credit: Stantec

Credit: Chad Lobato/NREL

Space Heat-ing

24%

Space Cool-ing2%

Pumps1%

Ventilation Fans5%

Domestic Hot Water

3%Exterior Lights

0%Lights

6%

Office Plug Loads22%

Task Lights0%

Data Center34%

Data Center Cooling0%

Data Center Fans1%

NREL RSF Energy Use Breakdown


Living in a ZEB: Every Watt Counts

•Whole building energy use = 283 Watts continuous per occupant

• 4-5 incandescent light bulbs per occupant continuous• $8500 of PV per occupant

•For every 1 watt continuous we save, we avoid $33 of PV needed to offset this 1 watt•Every watt counts!


Day vs. Night Plug and Process Loads

Annual Plug Load Energy Use Intensity (kBtu/ft2)

Unoccupied Hours Power Density (W/ft2)0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50

Occupied

Hours Power Density (W/ft2)

0.10 3.0 5.2 7.4 9.7 11.9 14.1 16.3 18.6 20.8 23.0 25.2 27.4 29.7 31.9 34.10.20 3.8 6.0 8.2 10.4 12.7 14.9 17.1 19.3 21.5 23.8 26.0 28.2 30.4 32.7 34.90.30 4.5 6.8 9.0 11.2 13.4 15.6 17.9 20.1 22.3 24.5 26.8 29.0 31.2 33.4 35.60.40 5.3 7.5 9.7 12.0 14.2 16.4 18.6 20.9 23.1 25.3 27.5 29.7 32.0 34.2 36.40.50 6.1 8.3 10.5 12.7 15.0 17.2 19.4 21.6 23.8 26.1 28.3 30.5 32.7 35.0 37.20.60 6.8 9.1 11.3 13.5 15.7 17.9 20.2 22.4 24.6 26.8 29.1 31.3 33.5 35.7 38.00.70 7.6 9.8 12.0 14.3 16.5 18.7 20.9 23.2 25.4 27.6 29.8 32.1 34.3 36.5 38.70.80 8.4 10.6 12.8 15.0 17.3 19.5 21.7 23.9 26.2 28.4 30.6 32.8 35.0 37.3 39.50.90 9.1 11.4 13.6 15.8 18.0 20.3 22.5 24.7 26.9 29.1 31.4 33.6 35.8 38.0 40.31.00 9.9 12.1 14.4 16.6 18.8 21.0 23.2 25.5 27.7 29.9 32.1 34.4 36.6 38.8 41.01.10 10.7 12.9 15.1 17.3 19.6 21.8 24.0 26.2 28.5 30.7 32.9 35.1 37.3 39.6 41.81.20 11.4 13.7 15.9 18.1 20.3 22.6 24.8 27.0 29.2 31.4 33.7 35.9 38.1 40.3 42.61.30 12.2 14.4 16.7 18.9 21.1 23.3 25.5 27.8 30.0 32.2 34.4 36.7 38.9 41.1 43.31.40 13.0 15.2 17.4 19.6 21.9 24.1 26.3 28.5 30.8 33.0 35.2 37.4 39.7 41.9 44.11.50 13.7 16.0 18.2 20.4 22.6 24.9 27.1 29.3 31.5 33.8 36.0 38.2 40.4 42.6 44.9

Only occupied about ⅓ of the time-Nights Unoccupied-Weekends Unoccupied-Holidays Unoccupied


66%7%

27%

Nights, Weekends, Holidays

Unoccupied workstations during the day

Annual Occupied Hours

15

• Nights, weekends, and holidays account for 66% of the year• A typical office building is unoccupied during this time

• During a typical work day, building occupants are only at their desk less than 30% of the time• Workstations are vacant and should be powered down during more than 70% of business hours

• Workstations should only be powered 7% of the year!


0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 230

10

20

30

40

50

60

70

80

90

100

At work, and away from desk

At work, and at desk

Time of Day

Occ

up

ancy

(%

)

References:http://www.gsa.gov/graphics/pbs/WorkPlace_Matters_FINAL508_lowres.pdf

http://www.gsa.gov/graphics/pbs/WorkPlace_Matters_FINAL508_lowres.pdf


•How can space efficiency reduce office equipment?• Maximize use of commons spaces

• Copy rooms• Break rooms

• Design to use stairs• Regenerative elevators

• Slower is ok

•Minimize distribution transformers•Exhaust transfer air for cooling of network/switch rooms•Opportunities to turn off parasitic office equipment

• Occupancy sensor power strips• Scheduled outlets

•Integrated datacenter cooling• Air side economizer• Evaporative cooling• Waste heat recovery

Plug and Process Load Opportunities:Design Team Opportunities


Elevators

Regenerative Traction Elevators– Machine Room Less Elevator– Space Savings– Recovers breaking energy and

converts it to AC electricity

Change elevator lighting to energy efficient fluorescent lighting or LEDs

Turn off lighting and fans when the elevator is unoccupied

Credit: Jürg Nipkow, Swiss Agency for Efficient Energy Use


•Document current space efficiency and plug load profiles•Multifunction Devices

• 75% less printers

•Workstation• Laptops, VOIP 2 W phones, 6 W LED task lights

•Efficiency datacenter operations• Blade servers with virtualization• ASHRAE temperature Guidelines• Fully contained hot aisle

•All the other “STUFF”• EnergyStar only a starting point• Hand operated compact shelving• Minimize individual stuff• Question all operations!

Plug and Process Load Opportunities:Owner Opportunities

Workstation Type Power Savings

Standard PC 400w 0%

Energy Star PC 300w 25%

Laptop 60w 85%

Thin Client 35w 91%


Energy Efficient Workspace

Typical 19”-24” Monitors30-50 Watts

24” LCD Energy Efficient Monitors18 Watts

Removing personal space heater saves 1500 Watts

VOIP phones 2 Watts

Power Strip on the desktop

Easy to access power button

Workstation load – 55W0.4 W/ft2 whole building plug

load intensity

Workstation load – 55W0.4 W/ft2 whole building plug

load intensity

Multi-function Devices 100 Watts (continuous)

Removing desktop printers saves

~460 Watts/Printer

Fluorescent task lights 35 Watts

LED task lights 6 Watts

Desktop Computer (Energy Star)300 Watts

Laptop 30 Watts


Multifunction Devices

• Multifunction energy-star 4.0 compliant devices

• Lower Maintenance• Higher performance• Reduce number of network printers by

75%• Strong justification will be required for

personal printers• Do not use banner pages• Default to duplex printing• Business processes are becoming

increasing paperless• Use recycled materials

Functions? Printing Copying Scan to mailbox Standard fax Fax from desktop


NREL Cyber-Security Policy

Evaluate policies and operations to ensure effectiveness

– NREL currently used a screensaver to lock unused computers

• The screensaver consumes on average 5W more than an idle computer

– Instead of a screensaver, if the monitors and computers went into standby there would be a savings of 70W per person

– ~$500,000 of PV saved– Anything multiplied by 800 is

a lot!

11:25:0411:25:1411:25:2411:25:3411:25:4411:25:5411:26:0411:26:1411:26:2411:26:3411:26:4411:26:5411:27:0411:27:1411:27:2411:27:3411:27:4411:27:5411:28:0411:28:1411:28:2411:28:3411:28:4411:28:5411:29:0411:29:1411:29:2411:29:3411:29:4411:29:5411:30:0411:30:1411:30:2411:30:3411:30:4411:30:5411:31:0411:31:1411:31:2411:31:3411:31:4411:31:5411:32:0411:32:1411:32:2411:32:3411:32:4411:32:5411:33:0411:33:1411:33:2411:33:3411:33:4411:33:5411:34:0411:34:1411:34:2411:34:3411:34:4411:34:5411:35:0411:35:1411:35:2411:35:3411:35:4411:35:5411:36:0411:36:1411:36:2411:36:3411:36:4411:36:5411:37:0411:37:1411:37:2411:37:3411:37:4411:37:5411:38:0411:38:1411:38:2411:38:3411:38:4411:38:5411:39:0411:39:1411:39:2411:39:3411:39:4411:39:5411:40:0411:40:1411:40:2411:40:3411:40:4411:40:5411:41:0411:41:1411:41:2411:41:3411:41:4411:41:5411:42:0411:42:1411:42:2411:42:3411:42:4411:42:5411:43:0411:43:1411:43:2411:43:3411:43:4411:43:5411:44:0411:44:1411:44:2411:44:3411:44:4411:44:5411:45:0411:45:1411:45:2411:45:3411:45:4411:45:5411:46:0411:46:1411:46:2411:46:3411:46:4411:46:5411:47:0411:47:1411:47:2411:47:3411:47:4411:47:5411:48:0411:48:1411:48:2411:48:3411:48:4411:48:5411:49:0411:49:1411:49:2411:49:3411:49:4411:49:5411:50:0411:50:1411:50:2411:50:3411:50:4411:50:5411:51:0411:51:1411:51:2411:51:3411:51:4411:51:5411:52:0411:52:1411:52:2411:52:3411:52:4411:52:5411:53:0411:53:1411:53:2411:53:3411:53:4411:53:5411:54:0411:54:1411:54:2411:54:3411:54:4411:54:5411:55:0411:55:1411:55:2411:55:3411:55:4411:55:5411:56:0411:56:1411:56:2411:56:3411:56:4411:56:5411:57:0411:57:1411:57:2411:57:3411:57:4411:57:5411:58:0411:58:1411:58:2411:58:3411:58:4411:58:5411:59:0411:59:1411:59:2411:59:3411:59:4411:59:5412:00:0412:00:1412:00:2412:00:3412:00:4412:00:5412:01:0412:01:1412:01:2412:01:3412:01:4412:01:5412:02:0412:02:1412:02:2412:02:3412:02:4412:02:5412:03:0412:03:1412:03:2412:03:3412:03:4412:03:5412:04:0412:04:1412:04:2412:04:3412:04:4412:04:5412:05:0412:05:1412:05:2412:05:3412:05:4412:05:5412:06:0412:06:1412:06:2412:06:3412:06:4412:06:5412:07:0412:07:1412:07:2412:07:3412:07:4412:07:5412:08:0412:08:1412:08:2412:08:3412:08:4412:08:5412:09:0412:09:1412:09:2412:09:3412:09:4412:09:5412:10:0412:10:1412:10:2412:10:3412:10:4412:10:5412:11:0412:11:1412:11:2412:11:3412:11:4412:11:5412:12:0412:12:1412:12:2412:12:3412:12:4412:12:5412:13:0412:13:1412:13:2412:13:3412:13:4412:13:5412:14:0412:14:1412:14:2412:14:3412:14:4412:14:5412:15:0412:15:1412:15:2412:15:3412:15:4412:15:5412:16:0412:16:1412:16:2412:16:3412:16:4412:16:5412:17:0412:17:1412:17:2412:17:3412:17:4412:17:5412:18:0412:18:1412:18:2412:18:3412:18:4412:18:5412:19:0412:19:1412:19:2412:19:3412:19:4412:19:5412:20:0412:20:1412:20:2412:20:3412:20:4412:20:5412:21:0412:21:1412:21:2412:21:3412:21:4412:21:5412:22:0412:22:1412:22:2412:22:3412:22:4412:22:5412:23:0412:23:1412:23:2412:23:3412:23:4412:23:5412:24:0412:24:1412:24:2412:24:3412:24:4412:24:5412:25:0412:25:1412:25:2412:25:3412:25:4412:25:5412:26:0412:26:1412:26:2412:26:3412:26:4412:26:5412:27:0412:27:1412:27:2412:27:3412:27:4412:27:5412:28:0412:28:1412:28:2412:28:3412:28:4412:28:5412:29:0412:29:1412:29:2412:29:3412:29:4412:29:5412:30:0412:30:1412:30:2412:30:3412:30:4412:30:5412:31:0412:31:1412:31:2412:31:3412:31:4412:31:5412:32:0412:32:1412:32:2412:32:3412:32:4412:32:5412:33:0412:33:1412:33:2412:33:3412:33:4412:33:5412:34:0412:34:1412:34:2412:34:3412:34:4412:34:5412:35:0412:35:1412:35:2412:35:3412:35:4412:35:5412:36:0412:36:1412:36:2412:36:3412:36:4412:36:5412:37:0412:37:1412:37:2412:37:3412:37:4412:37:5412:38:0412:38:1412:38:2412:38:3412:38:4412:38:5412:39:0412:39:1412:39:2412:39:3412:39:4412:39:5412:40:0412:40:1412:40:2412:40:3412:40:4412:40:5412:41:0412:41:1412:41:2412:41:340.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0 Computer Power Consumption

Monitor and Computer Screensaver On (W)Monitor Standby (W)Monitor and Computer Standby (W)

Time

Po

wer

(W

)


0:02:471:19:47

2:36:473:53:47

5:10:476:27:47

7:44:479:01:47

10:18:47

11:35:47

12:52:47

14:09:47

15:26:48

16:43:48

18:00:48

19:17:48

20:34:47

21:51:47

23:08:470.0

1000.0

2000.0

3000.0

4000.0

5000.0

6000.0

NREL Old Coffee Car Daily Load Profile

Wells Food Warmer

Island Oasis Ice Shaver Blender

Amana Microwave

Bunn Omatic Coffee Maker

CMA Grinder

Curtis Grinder

Arctic Air Refrigerator

Haier Refrigerator (Empty)

Haier Refrigerator (Full)

TRUE Refrigerator

Whirlpool Freezer

Ariston Hot Water Heater

Bunn Hot Water System

Black and Decker Toaster

Boston Acoustics Radio

Royal Cash Register

VeriFone Credit Card Machine

GE Phone

Astoria Espresso Machine (EST)

Time of Day

Po

wer

Co

nsu

mp

tio

n (

W)

$15,000 of PV to run nighttime loads


RSF Data Center

Moving towards high-density blade servers– Highly efficient power supplies– Variable speed fans– Wake-on-LAN

Server virtualization – Ratio: 4-8 to 1

Dynamic Workload management– Server resources go from “always on” to “always available”– Resources are powered up or down as resources are needed

Hot aisle containment with airside economizer and evaporative cooling

Target PUE of 1.1 vs. legacy PUE of 2.5

Expected reduction of 65% in total data center power consumption


RSF Plug Load Reduction Strategies

Elevators– Use energy efficient traction elevators– Change elevator lighting to energy efficient fluorescent

lighting– Turn off elevator lighting when the elevator is

unoccupiedBreak Rooms

– Increase the number of people that use each break room from approximately 40 to 60

– Eliminate the cooler on the drinking fountainTask Lights

– Move from 35W fluorescent task lights to 6W LED task lights

Phones– Go from 1000 standard phones to 1000 VOIP phone

that consumes 2W eachCopiers, Printers, Fax Machines

– Decrease the number people that use individual copiers, printers and fax machines

– Increase the number of people that use common, or group, copiers, printers and fax machines from 15 to 20

– Increase the use of all-in-one machinesComputers

– Go from approximately 260 laptops, 33% of staff, to 720, 90% of staff, ensure standby mode works for all workstations

Data Center– Blade Servers with Virtualization– High efficiency UPS– 65W/employee current to 48W/employee in RSF

The result of these strategies is a 47% reduction in plug loads

Baseline RSF0.00

5.00

10.00

15.00

20.00

Baseline vs RSF Plug Load EUICoffee Kiosk

Elevator Lighting

Elevators

Drinking Fountains

Vending Machines

Microwaves

Coffee Pots

Refrigerators

Task Lights

Phones

Fax Machines

Copiers

Printers

Computers

Data Center

Conference Room Equipment

Telecom Room Equipment

Misc

EU

I (k

Btu

/ft2

)


0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

Model Av-erageOctober 2010November 2010December 2010January 2011February 2011March 2011April 2011May 2011June 2011July 2011August 2011

Time of Day

Po

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Den

sity

(W

/ft2

)

October 2010 – August 2011 Plug Load Power Density

Note: The elevators are included in the plug loads

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Operations Lessons – Plug loads

26

• Daytime loads lower than predicted • Model did not account for actual occupancy

• Only ~75% of occupants actually at their desk any given day

•Nighttime loads still difficult• Programmable outlets added after the fact• Automatic Laptop standby/hibernate functionality

deployed system-wide• Monitors go to sleep well• Laptops have insomnia (except Macs)• Need a forced standby function and not rely on integrated

windows standby• Ensure Wake-On-LAN functionality

• Staff have not fully utilized desktop based power strip controls

•Continued staff educational programs•Need to develop an optimal workstation plug load control system

• Programmable power strips to disconnect all plugs at night?

• Easy to use office plug load disconnect switch?


Operations Lessons – Plug loads Cont..

27

• 2 Refrigerators per break room sometimes excessive– Some groups unplug and don’t use second refrigerator

• Utilize more switched outlets or controllable outlets• Or allow for programmable plugs• Energy Monitoring Displays on all night…


Ice Machine Timed Outlet

28

• The devil is in the details… • Saved 52% energy use on an ENERGY STAR® ice

machine with a $15 programmable outlet



0:09

:30

4:56

:30

9:43

:30

14:3

0:30

19:1

7:30

0:04

:30

4:51

:30

9:38

:30

14:2

5:30

19:1

2:30

23:5

9:30

4:46

:30

9:33

:30

14:2

0:30

19:0

7:30

23:5

4:30

4:41

:30

9:28

:30

14:1

5:30

19:0

2:30

23:4

9:30

4:36

:30

9:23

:30

14:1

0:30

18:5

7:30

23:4

4:30

4:31

:30

9:18

:31

14:0

5:33

18:5

2:36

23:3

9:39

4:26

:42

9:13

:45

14:0

0:48

18:4

7:51

23:3

4:54

0

200

400

600

800

1000

1200

1400

Uncontrolled Ice Machine

Timer Controlled Ice Machine

Time of Day

Po

wer

(W

)

Weekly Energy Savings: 28.6 kWh

Weekly Energy Savings: 52%

Ice Machine Timed Outlet

29

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October 2010 Plug Load Power Density

0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

Model Weekday Plug Loads

Model Weekend Plug Loads

RSF Hourly Weekday Plug Loads

RSF Average Weekday Plug Loads

RSF Hourly Weekend Plug Loads

RSF Average Weekend Plug Loads

Time of Day

Po

wer

Den

sity

(W

/ft2

)



November 2010 Plug Load Power Density

0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

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0.35

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0.65







Time of Day

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(W

/ft2

)



December 2010 Plug Load Power Density

0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

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0.25

0.30

0.35

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0.45

0.50

0.55

0.60

0.65







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January 2011 Plug Load Power Density

0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65







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)



February 2011 Plug Load Power Density

0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65







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)



March 2011 Plug Load Power Density


0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65







Time of Day

Po

wer

Den

sity

(W

/ft2

)


April 2011 Plug Load Power Density


0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65







Time of Day

Po

wer

Den

sity

(W

/ft2

)


May 2011 Plug Load Power Density


0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65







Time of Day

Po

wer

Den

sity

(W

/ft2

)


June 2011 Plug Load Power Density


0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65







Time of Day

Po

wer

Den

sity

(W

/ft2

)


July 2011 Plug Load Power Density


0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65







Time of Day

Po

wer

Den

sity

(W

/ft2

)


August 2011 Plug Load Power Density


0 2 4 6 8 10 12 14 16 18 20 22 240.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65







Time of Day

Po

wer

Den

sity

(W

/ft2

)


Operational Lessons- Datacenter

41

•Fully containing hot aisle difficult• Custom aisle floor and door seals• Ensure equipment designed for cold

aisle containment • And installed to pull cold air

– Not hot air…

•Have run ~1.1-1.15 PUE•A few hot spots were driving up PUE…•Summer time PUE of 1.20 because of increased cooling

•Starting to control hot aisle based onreturn temperature of ~80F•65 Watts/person to 38 Watts/person

• But NREL has doubled in size• Modeled 65 watts/person for 1200

people• Using 38 watts/person for 2300 people

NR

EL/

PIX

17

897

Cre

dit:

Mar

jorie

S

chot

t/NR

EL


10/1/10 11/30/10 1/29/11 3/30/11 5/29/11 7/28/110.70

0.80

0.90

1.00

1.10

1.20

1.30

1.40

1.50

-20

-5

10

25

40

55

70

85

100

RSF Data Center PUE

Outdoor Temperature

PU

E

Ou

tdo

or

Tem

per

atu

re (

°F)

Data Center PUE


Monthly Average PUE

October2010

November2010

December2010

January2011

February2011

March2011

April2011

May2011

June2011

July2011

August2011

September2011

October2011

November2011

December2011

1.05

1.10

1.15

1.20

1.25

1.30

PU

E


10 Steps to Address PPLs

1. Establish a

PPL Champion

2. Develop a Business

Case

3. Benchmark

Conventional Equipment and

Operations

4.Identify

Occupant’s Needs

5. Meet Needs as Efficiently as Possible

6. Turn It Off at

Night

7. Design Team:

Identify Applicable Strategies

8. Procurement

Decisions and Policy

9.Address

Unique PPLs

10.Occupant

Awareness


Step 1: Establish a PPL Champion

Purpose:

To initiate and help implement PPL strategies.

Skills needed:• Understanding of:

• technical energy efficiency opportunities

• design strategies

• Ability to: • apply business model• question operations, institutional

policies, and procurement processes


Step 2: Develop a business case for addressing PPLs

Avoided Cost of Renewables (ACR):

Equates the cost of PPL efficiency measures to avoided renewable costs.

Gives all parties a financial incentive to investigate PPLs.

ACR for the RSF:

Used to justify demand-side efficiency measures.

1 Watt continuous saved = $33 worth of PV was avoided. Additional loads must be offset with renewables.

The PV cost avoided by PPL reductions exceeded $4 million.

Photo Credit: Dennis Schroeder PIX 17842


Step 3: Benchmark your conventional equipment and operations

Methods:• Submeter panels (if properly organized)• PPL power meters• Combination of submetering and equip.

spec. sheets can be used

Data:• Understand when equipment is used• Highlight opportunities to turn off • Basis of comparison for financial

calculations

Figure Credit: Microsoft Clip Art


Step 4: Be willing to identify occupants’ true needs

True need:

Equipment or procedure required to achieve a given business goal or an assigned task.

Understand:

What do occupants produce as part of their jobs and what tools do they require?

Every occupant, including those working in sensitive operations must be accounted for.

Nonessential equipment: •A business case must be made for continued use.


Step 5: Meet needs as efficiently as possible

Search energy efficient equipment databases.

Nonrated equipment: •Investigate the most efficient model•Turn off when not in use (if possible)

Pay attention to parasitic loads.

Photo Credit: Chad Lobato


Step 6: Turning it all off

Office buildings are typically unoccupied 66% of year.

KEY: Reduce power density during nonbusiness hours.

Photo Credit: Jennifer Schieb


Step 7: Encourage the design team to identify all applicable PPL strategies

Question standard specifications, operations, and design standards.

Maximize space efficiency.

Integrate PPL control strategies into the building’s electrical system:• Switches• Vacancy sensors• Timed disconnects for outlets• Controlling outlets through the Building Management System (BMS)

Other loads:• Elevators • Transformers• Process cooling systems• Data centers


Step 8: Institutionalize procurement decisions and policy programs

Day-to-day energy efficiency: Depends on the decisions of occupants, facility managers, and owners.

Identify decision makers who can:• Institutionalize PPL measures through procurement decisions and policy programs.

• Promote buy-in.

• Identify unbreakable and unchangeable policies.


Step 9: Address unique miscellaneous PPLs

EXAMPLE: Contractors and food service areas.

Building owner can contractually require or provide the most efficient equipment available.

Case-by-case evaluation:• Energy-efficient equipment may not be available and may be

restricted from being turned off (e.g. ATM)• Manufacturers may be able to recommend alternatives.

Photo Credit: Chad Lobato


Step 10: Occupant awareness

Encourage and allow to “do good”.

PPL strategies should counteract “bad users.”

Emphasize importance of turning off personal electronics when leaving a workspace.

Photo Credit: Jennifer Scheib


DOE Commercial Buildings Resource Database:Additional Plug Load Guidance

Search for:• Plug or Miscellaneous

Electric Load• Datacenter

http://apps1.eere.energy.gov/buildings/commercial/resource_database/


Thanks and Questions

Shanti Pless

[email protected]

www.nrel.gov/rsf

mailto:[email protected]

plug load efficiency for zero energy buildings webinar 1 29 2013

Engineering

site energy

office of energy efficiency

renewable energy

sustainable energy

department of energy

energy future9

energy future http

energy future3 nrel