results and lessons learned from a commercial plug- load reduction study.

1. ADVANCING THE LAST FRONTIER-
REDUCTION OF COMMERCIAL
PLUG LOADS
Scott Hackel, Seventhwave
Chris Plum, Center for Energy and the Environment
Rick Carter, LHB, Inc.
2016 ACEEE Summer Study on Energy Efficiency in Buildings

2. REDUCTION OF COMMERCIAL PLUG LOADS
OUR PROJECT APPROACH
Characterize: 35 offices
Individually measure: 8 offices, 700+ points
Test strategies: 5 strategies
Gauge satisfaction: 290+ users

3. REDUCTION OF COMMERCIAL PLUG LOADS
WORKSTATION MONITORING
Workstation
logger
CPU logger

4. REDUCTION OF COMMERCIAL PLUG LOADS
PLUG LOAD INVENTORIES
Self-reported
(N=34 offices)
Field observations
(N=8)
Average Range Average Range
Area per person (ft2) 280 170 - 600 230 198 - 273
Desktop/workstation 0.65 0 - 1.4 0.49 0 - 1.20
Laptop/workstation 0.43 0 - 1 0.56 0 - 1.00
Monitor/workstation 1.32 0.2 - 2.4 1.58 1 - 2.60
Task Light/workstation 0.80 0 - 2.6 0.68 0 - 1.40
All other 1.40 0 - 4.8 0.97 0 - 4.00
Total Plug Devices 4.6 1-10.4 4.3 1-11
Phone/workstation 1.00 0.6 - 1.8 0.98 0.80 - 1.03

5. OFFICE INVENTORY (COMMON SPACES)
5
Equipment Type Total Number
Observed
Sites with 1 or more
(out of 8)
Desktop Printer 27 6
Multi-functional Device/copier 22 8
Microwave 21 7
Flatscreen tv/digital display 18 6
Coffeemaker 16 7
Refrigerator 14 7
Voice conferencing equipment 10 4
Mini-fridge 7 4
Electric stapler 7 4
Floor based printer 6 3
Toaster 6 5
Shredder 6 3
Projector 6 3

6. REDUCTION OF COMMERCIAL PLUG LOADS
PLUG LOAD REDUCTION STRATEGIES
CREDIT:Tricklestar
APS – Occupancy sensor
APS – Foot pedal
Basic timer
Computer power management
Behavior campaign

7. REDUCTION OF COMMERCIAL PLUG LOADS
BEHAVIOR CHANGE
CAMPAIGN
CREDIT: LHB Architects

8. REDUCTION OF COMMERCIAL PLUG LOADS
ENERGY IMPACTS

9. REDUCTION OF COMMERCIAL PLUG LOADS
ENERGY IMPACTS
Annual energy savings
kWh per
station
%
(with 95% conf. int.) N
Occupancy sensor 67 21.7% ± 14% 95
Computer power management 106 29.1% ± 18% 116
Foot pedal 42 19.0% ± 13% 74
Foot pedal + behavior campaign 70 22.4% ± 13% 48

10. REDUCTION OF COMMERCIAL PLUG LOADS
ENERGY IMPACTS
0
20
40
60
80
100
120
140
AnnualSavings(kWh)

11. REDUCTION OF COMMERCIAL PLUG LOADS
IMPACT OF BEHAVIORAL ELEMENTS
City public works APS savings alone:
…. with behavior campaign:
Engineering APS savings alone:
… with behavior campaign:
34 kWh
49 kWh 57 kWh
84 kWh

12. REDUCTION OF COMMERCIAL PLUG LOADS
PARTICIPANT FEEDBACK

13. REDUCTION OF COMMERCIAL PLUG LOADS
PARTICIPANT FEEDBACK
Advanced power strips, by site
• No major productivity issues
• Lowest “acceptance” rate 69%
Computer power mgmt., by site
• Technology disrupted productivity
for some specific user types
• Sites without technical issues had
high acceptance rates: >77%

14. REDUCTION OF COMMERCIAL PLUG LOADS
LESSONS FROM THE FIELD
Computer power management was initially resisted at most sites.
• Upside: an energy champion
• Downside: incompatible software
Even “foolproof” equipment can be misused
• Upside: 90% of users had no issues
• Downside: some users inadvertently caused malfunction
Users don’t always plug equipment back in the same outlet
• Upside: majority of plugs were never touched
• Downside: issue primarily occurred with laptops

15. REDUCTION OF COMMERCIAL PLUG LOADS
KEY TAKEAWAYS
• We see evidence of loads moving away from the
workstation, but significant load remains.
• Tier 2 APS work well.
• Computer power management works even better,
but…
• There’s value in discussing behavior.

16. REDUCTION OF COMMERCIAL PLUG LOADS
ACKNOWLEDGEMENTS
This project was supported in part by a grant from the Minnesota Department of Commerce
through the Conservation Applied Research and Development (CARD) program.

17. Questions?
Scott Hackel
shackel@seventhwave.org
Chris Plum
cplum@mncee.org
Rick Carter
rick.carter@lhbcorp.com