Reduction of building plug loads

ADVANCING THE LAST FRONTIER:

Thea Rozenbergs, LHB

Chris Plum, Center for Energy and Environment

Seventhwave (Research Partner)

WHAT IS A PLUG LOAD?

All energy consumed by appliances, office equipment,

and anything else that is not a part of the facility’s

primary HVAC, lighting, water heating or conveyance

(elevators, escalators, etc.) systems. This includes

just about anything that is actually plugged into an

outlet. 0

20

40

60

80

100

120

140

Total EUI

PLUG LOAD EUI

126

95

78

KBTU/SQ.FT./YEAR

20 20

16% 26%

STUDENT CENTER ADDITION AND RENOVATION

CO

DE

BASE

STA

ND

ARD

DES

IGN

MO

DEL

2

ENERGY USE ATTRIBUTED TO PLUG LOADS

0

50

100

150

200

250

300

350 PLUGLOADSURVEYRESULTSTheenergymodelsfor19B3projectsshowthatplugloadsrangefrom5-43%ofthetotaldesignenergyuse,withaweightedaverageof15%.

EUI

29% 43% 13% 26%

14%

21%

13% 5% 9% 33% 22% 43% 16% 15% 0%

15%

Plug loads were not included in the energy modeling process

3

WHAT’S THE PROBLEM?

While plug loads are

increasing, overall energy

use intensity needs to

decrease.

Currently Plug Loads = 11%

of total electric load 0

10

20

30

40

50

60

70

80

90

100

Typical 2010 2015 2020 2025 2030

Ene

rgy

Use

Inte

nsity

(kB

tu/s

f)

Total EUI Plug load

4

HISTORIC APPROACH TO PLUG LOADS

5

B3/SB 2030 PLUG LOAD REQUIREMENTS

E.1B:

For all New Buildings and Major Renovations, document

predicted and actual energy use by type in the B3 Guidelines

Tracking Tool, including recording modeled plug loads and sub-

metered actual plug loads separately from other electrical loads

in the built project.

6

MINNESOTA ENERGY CODE

ASHRAE 90.1-2010 Prescriptive Path requires

50% of electrical outlets in offices and

computer classrooms must be on automatic

control so they can be switched off when the

room is unoccupied

7

RESEARCH STUDIES

§  Electricity Savings Opportunities for Home Electronics and Other

Plug-In Devices in Minnesota Homes | May 2010

§  Office Plug Load Reduction Strategies | October 2016

§  Small Embedded Data Center Program Pilot | June 2017

§  Using Network Switches to Operate and Control Lighting and Plug

Loads in Commercial Building | October 2020

8

OFFICE PLUG LOAD REDUCTION STRATEGIES

ACKNOWLEDGEMENTS

This project was supported in part by:

Minnesota Conservation Applied Research and Development (CARD)

Grant Program

10

OVERVIEW

Background

Plug load energy in a typical office

Saving energy

Economics

Impact of behavior

Context

11

CR

ED

IT: S

amsu

ng

12

BACKGROUND AND METHOD

DISCOVERY

had at least one sustainability strategy… are billed by actual use…

Most surveyed offices…

5

5

5

5

5

7

9

18

22

Other:

AcEvetrainingonenergyusereducEon

Buildingand/orinteriorspacemeetssustainablebuildingguidelines(e.g.LEED,EnergyStar)

Officesustainabilitychampion

OnsiterenewableenergyproducEon

Office-widepolicyonpersonaldevices

Network-widecontrolofcomputerpowermanagement

SustainabilityincorporatedintoorganizaEonmission/vision/policy

Equipmentpurchasing(energy)standards(e.g.EnergyStarequipmentonly,LEDtasklights)

#ofTimesEachStrategyisImplemented

14

PLUG LOAD INVENTORIES

Self-reported (N=34 offices)

Average Range

Area per person (ft2) 280 170 - 600

Desktop/workstation 0.65 0 - 1.4

Laptop/workstation 0.43 0 - 1

Monitor/workstation 1.32 0.2 - 2.4

Task Light/workstation 0.80 0 - 2.6

All other 1.40 0 - 4.8

Total Plug Devices 4.6 1-10.4 Phone/workstation 1.00 0.6 - 1.8

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DATA COLLECTION

First divided by treatment vs control

§  First Visit: Inventory and monitoring §  Second Visit: Install plug load control

measures § Repeated up to 2 more times

§  Third visit: Remove equipment and download data

Control Treatment

16

MONITORING

Monitored total workstation electric AND computer only

17

ENERGY SAVING STRATEGIES

Advanced power strips: §  APS – Occupancy sensor §  APS – Foot pedal Computer power management Behavior campaign + APS Common area equipment: Basic timer CREDIT: Tricklestar

18

PLUG LOAD ENERGY IN A TYPICAL OFFICE

CONTROLLABLE PLUG LOADS

§  Over 40% of typical office plug load is controllable

§  Workstations make up 53% of controllable load

§  Common area is the rest § Office equipment 30% § Break room 16%

4.1

3.6

[VALUE].0

[VALUE].0

Plug Load EUI ≈ 19 kBtu/sq.ft.

Workstation

Common Areas

Server Room

Other MELs

20

TYPICAL LOADS By day…

1 4 7 10 13 16 19 22

Plu

g lo

ad p

ower

Hour

Computer Other devices

0

300

600

900

1,200

1,500

1,800

Plu

g lo

ad e

nerg

y (k

Wh)

N = 290

…and for the year.

21

TYPICAL LOADS - TRENDS

22

SAVING ENERGY IN WORKSTATIONS

APS – OCCUPANCY SENSOR

CREDIT: Tricklestar

24

APS – FOOT PEDAL

CREDIT: Tricklestar

25

COMPUTER POWER MANAGEMENT

CREDIT: LHB Architects

Consistent with ENERGY STAR recommendations

26

WORKSTATION SAVINGS

27

WORKSTATION SAVINGS

28

WORKSTATION SAVINGS

ENERGY SAVINGS

kWh per station

% (with 95% conf. int.)

N

Occupancy sensor

Computer power management

Foot pedal

Foot pedal + behavior campaign

67

106

42

70

21.7%

29.1%

19.0%

22.4%

± 14%

± 18%

± 13%

± 13%

95

116

74

48

29

WORKSTATION SAVINGS

These strategies are effective §  As fraction of night + weekend energy:

53–69%

Reducing plug loads saves cooling energy too: §  CPM: add 4–7% savings §  APS: add 0–3% savings

CR

ED

IT: T

hom

as K

else

y

30

TARGETING WORKSTATIONS?

Difficult to target based on device count alone

Look instead for: ü  Printers ü  Very large monitors ü  Desktop PCs ü  Those without CPM

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HOW DOES THIS COMPARE TO RESIDENTIAL?

Everything from televisions to toasters, 15-30% of electric use

32

End Use Percent of electric use

Percent of savings potential

TV and audio related 36% 22% - manually unplug 10% - turn off/timer 5% - power strip

Computer related 21% 40% - computer power management 5% - manually unplug 6% - power strip

HVAC related 25% 3% - turn off

Appliances (coffeemakers, toasters, microwaves, cordless phone)

8% 6% - unplug/timer

Other (clocks, chargers, hand tools, etc.) 10% 3% - timer/unplug

PEAK DEMAND IMPACT

0

40

80

120

160

200

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Plu

g lo

ad p

ower

per

wor

ksta

tion

(W)

Hour

Baseline Occupancy sensor CPM

33

PARTICIPANT FEEDBACK

APS OC APS FP CPM

34

PARTICIPANT FEEDBACK

35

IMPLEMENTING CPM

Problems with solutions: Remote access | Pushing updates | Problem software | Other IT priorities 36

CONCLUSIONS FOR WORKSTATIONS Computer power management §  Not widely implemented §  Effective with existing software §  IT concerns have solutions

Advanced power strips §  Simple controls can save Cooperation: IT + Sustainability staff

37

SAVING ENERGY IN COMMON AREAS

COMMON AREA EQUIPMENT

PH

OTO

CR

ED

IT: W

ikim

edia

com

mon

s

Evaluate needs! Annual energy

usage

Desktop printers

Medium-sized MFDs

Coffeemakers

Televisions

Water coolers

170

352

548

67

386

kWh

39

COMMON AREA TIMER SAVINGS

40

COMMON AREA EQUIPMENT - OTHER

§  TV backlight settings

§  Choice of coffee service

760 kWh

CR

ED

IT: A

dam

Dac

hls

280 kWh 41

PARTICIPANT FEEDBACK

Common area equipment timers:

96% of respondents indicated that they did not notice any change/inconvenience

Most issues were related to equipment that is not designed for hard shutdown (MFDs, video conferencing equipment, etc.)

42

ECONOMICS

COSTS

§  APS . . . . . . . . . . . . . . . . . . . . . . . .

§  APS—for new workstation. . . . . .

§  Common area timers . . . . . . . . . .

§  CPM . . . . . . . . . . . . . . . . . . . . . . . .

$55

$35

$36

$17

44

COSTS + BENEFITS

45

IMPACT OF BEHAVIOR

BEHAVIOR CAMPAIGN PLANNING

Stakeholder interviews revealed the following design needs: §  Allow user to easily and conveniently turn off the devices. §  Remind user that the devices have been left on. §  Help create social norms to help others perform the action. §  Allow others like co-workers or facilities/custodial personnel to

help the action be performed.

Solution: §  APSs with foot switches

§  LED status lights

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BEHAVIOR CAMPAIGN + APS

CREDIT: LHB Architects

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IMPACT OF BEHAVIOR

City public works APS savings alone:

… with behavior campaign: Engineering APS savings alone:

… with behavior campaign:

34 kWh

49 kWh 57 kWh

84 kWh

49

BEHAVIOR CHANGE CAMPAIGN

CREDIT: LHB Architects

“What the lights are good for is providing awareness of the energy state of my cubicle.”

“The blue indicator lights were often called ‘the blue light of shame.’”

Social norm “Lights off!” 50

CONTEXT, CONCLUSIONS

CHECK THE CLOSET

0

200

400

600

800

1000

1200

Engineers, desktops Non-profit research, laptops Architects, desktops

Ene

rgy

usag

e pe

r use

r (kW

h)

Workstation energy Server energy

PH

OTO

CR

ED

IT: S

amsu

ng

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BROADER CONTEXT

0

10

20

30

40

50

60

70

80

90

100

1 2 3 3 4 4 4 4 4 4 5 5 5 6 6 6 7 7

Plu

gloa

d as

par

t of t

otal

EU

I

Climate Zone (as outlined by IECC)

Targeting plug load during design is an effective strategy….

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ENERGY USE ATTRIBUTED TO PLUG LOADS

0

50

100

150

200

250

300

350 PLUGLOADSURVEYRESULTSTheenergymodelsfor19B3projectsshowthatplugloadsrangefrom5-43%ofthetotaldesignenergyuse,withaweightedaverageof15%.

EUI

29% 43% 13% 26%

14%

21%

13% 5% 9% 33% 22% 43% 16% 15% 0%

15%

Plug loads were not included in the energy modeling process

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PLUG LOAD CASE STUDY LHB OFFICE

PROCESS

§  Create an Energy Management Team

§  Submeter plug loads to create a baseline

§  Set goals

§  Take action and record as “Events” in B3 Benchmarking

§  Track results

56

SUBMETERS

57

SUBMETERS + INTERVAL METERS

58

BASELINE

[VALUE]

9

[VALUE]

3

13

10

ANNUALDISTRIBUTION&COSTOFOFFICEENERGYUSE

(kBtu/SF-Year)

?

$5,575$7,247

$1,672

NATIONAL AVERAGE

77 EUI

LHB-MSP OFFICE (2016)

ELECTRIC EUI 27

AVERAGE OFFICE (CBECS 2012)

ELECTRIC EUI 33 LHB-MSP Energy Update - January 2017

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CHECK THE CLOSET

0

200

400

600

800

1000

1200

Engineers, desktops Non-profit research, laptops Architects, desktops

Ene

rgy

usag

e pe

r use

r (kW

h)

Workstation energy Server energy

PH

OTO

CR

ED

IT: S

amsu

ng

60

GOALS

Data Center: 15% reduction

Plug loads: 20% reduction

Total Electricity: 16% reduction

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13.310.6 10.7

10.2

8.7 9.9

3.5

3.54.1

-

5

10

15

20

25

30

2016Actual 2017Goal 2017Actual

LHB-MSPElectricityUseIntensity(kBtu/sf)

LighEng

DataCenter

PlugLoads

ACTIONS

§  Computer power management

§  Advanced power strips

§  Behavior campaign

§  Updates at staff meeting

§  Education on use of advanced power strips

§  Feedback meters

§  Outreach prior to holiday weekends

62

RESULTS

63

RESULTS

19.8% reduction in plug loads

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28.1 26.8 27.0 27.2 26.6 26.824.6

27.3 25.9 25.6 25.1 24.6 25.0 23.2 23.7 22.9 21.7

-

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

-

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

Aug-16 Sep-16 Oct-16 Nov-16 Dec-16 Jan-17 Feb-17 Mar-17 Apr-17 May-17 Jun-17 Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec-17

kBtu/sf

kBtu

LHB-MSPElectricityUse2016-2018(kBtu)

MonthlyEUI DataCenter LighEng PlugLoads

NEXT STEPS

§  Behavior campaign

§  Implement monitor brightness adjustments

§  Evaluate opportunities for remote desktop users

§  Plug load competition

§  Efficient equipment purchasing policy + standard for new workstations

§  Timer controls for common area equipment

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BULLITT CENTER CASE STUDY

http://www.bullittcenter.dreamhosters.com/building/building-features/

92 EUI = Typical Office Building 16 EUI = Bullitt Center 31.4% of EUI = Plug Load

**PAE Consulting Engineers, Inc.

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BULLITT CENTER CASE STUDY

http://www.bullittcenter.dreamhosters.com/building/building-features/

TAKES ADVANTAGE OF THE SUN §  82% of interior is naturally daylit (reduces task lighting) §  14,303 sq.ft. solar array (230,000 kWh/year) ACTIVE DESIGN §  Irresistible stair design encourages use §  Hidden elevator SMART TECHNOLOGICAL CHOICES §  Regenerative elevator designed by KONE converts potential energy from braking

into useable electricity which saves 60% of its energy §  Energy Efficient Computers §  Computerized systems to help manage building systems MEASUREMENT & FEEDBACK LOOP §  Dashboard shows real-time data about energy and water use §  Each tenant has agreed to an energy allowance as part of lease

92 EUI = Typical Office Building 16 EUI = Bullitt Center 31.4% of EUI = Plug Load

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DESIGN IMPLICATIONS Target plug loads §  New codes/Energy Design Assistance

§  Separate plug loads onto dedicated electrical panels

Tailor workspaces §  Equipment size

§  Workstation types

Kitchenettes and common spaces §  Number, location, and efficiency of equipment Lighting, thermal comfort §  Reduce need for personal task lights, heaters & fans

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KEY TAKE-AWAYS

§  Relatively simple solutions are available to save 30% or more

§  There’s value in discussing behavior

§  IT can impact energy efficiency

§  Though some loads are moving out of the workstation, significant savings remains

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FOR MORE INFORMATION

Energy Star https://www.energystar.gov/products/reduceitenergycosts

https://www.energystar.gov/campaign/home?s=mega

Better Buildings: Myth Busting Market Barriers to APS https://betterbuildingssolutioncenter.energy.gov/myth-busting-market-barriers-advanced-power-strips

NBI: Plug Load Best Practices Guide https://newbuildings.org/resource/plug-load-best-practices-guide/

Minnesota Power Rebates link https://www.mnpower.com/ProgramsRebates

§  https://www.energystar.gov/products/low_carbon_it_campaign/put_your_computers_sleep

§  https://betterbuildingssolutioncenter.energy.gov/myth-busting-market-barriers-advanced-power-strips

§  Lobato 2011. C. Lobato, S. Pless, M. Sheppy, and P. Torcellini. Reducing Plug and Process Loads for a Large Scale, Low Energy Office Building: NREL’s Research Support Facility. Proceedings of the 2011 ASHRAE Winter Conference, Las Vegas, NV. January 2011. Atlanta, ASHRAE.

§  http://newbuildings.org/wp-content/uploads/2015/11/PlugLoadBestPracticesGuide1.pdf §  https://eetd.lbl.gov/publications/methods-for-detailed-energy-data-co-0

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NEED MORE DETAIL?

Download the study See a fact sheet and the full report: seventhwave.org/commercial-plug-load-study

Contact us: Thea Rozenbergs, LHB, thea.rozenbergs@lhbcorp.com

Chris Plum, Center for Energy and Environment, cplum@mncee.org

Scott Hackel, Seventhwave, shackle@seventhwave.org

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