Submetering Technologies –

Results from field demonstrations

Dylan Cutler

September 20th, 2018

Rocky Mountain Utility Exchange – 2018

Aspen, Colorado
NREL | 2

Anatomy of Circuit-Level Submetering

• User interface – provides data access and 

insights/rules/alerts/etc.

• Cloud hosted data storage – Remote data store. 

Often can be accessed programmatically

• Communications bridge/Local data logger –

Collects meter data and transmits data to cloud

• Meter – Collects data and processes

• Current transformers – Measures current flow
NREL | 3

Technologies Tested

• Captures power consumption from up to 42 

distinct circuits

• CTs and voltage tap to capture electrical 

measurements

• Proprietary board/data acquisition system

• Data is transferred to cloud and presented 

in custom dashboard

• Captures electrical current (and voltage for PAN- 42) and calculates power consumption of 

individual circuits

• Self powered sensors 

• Wireless transmission of data from sensors to 

bridge

• Data is transferred to cloud-based servers and 

presented in custom dashboard with analytics

Enertiv Panoramic Power
NREL | 

4

Lab Testing

Appliance Voltage Dryer On Water

Heater On Range On

Refrigerator 120

Dishwasher 120

Washer 120

Lighting (All) 120

Lighting (240V) 240

Dryer 240X

Water Heater 240X

TV/DVD 120

Range 240X

Dryer 240X

Dryer 240XX

Dryer 240XX

Dryer 240XXX

Lighting (All) 120

Lighting (All) 120X

Lighting (All) 120X

Lighting (All) 120XX

Single Test Interference Test
NREL | 5

Field Testing

Salt Lake City Courthouse, Utah Cesar Chavez, Denver

Reference Metering
NREL | 6

Salt Lake City Results

 With high-accuracy CTs this system met accuracy goals of <5% energy error, <1% RMSPE
NREL | 7

Fault Detection and M&V of ECM

• High PUE calculated 

for server room (2.8)

• CRAC Units 

identified as fighting

• Reprogrammed by 

local technician

• Resulted in ~11% 

HVAC savings for 

server room

10

15

20

25

40 50 60 70 80 90 100

HVAC Power [kW]

Outdoor Temperature [0F]

Post-retrofit Pre-retrofit

0

1

2

3

4

5

Power (kW)

CRAC 1 CRAC 2 CRAC 3
NREL | 8

Denver Results
NREL | 9

Denver Results

Before After

 Power factor/voltage estimates critical, did not meet accuracy requirements
NREL | 10

Fault Detection and Data integration

 Annual savings of 1.3% would pay off 

system, action on chiller ECM would 

save 1.1%
NREL | 11

Use Cases vs. Technology Types

Tenant or 

Equipment 

Billing

Fault 

Detection & 

Diagnostics

Energy Visibility 

or Benchmarking

M&V of ECMs Tenant 

Engagement

Panel Meter –

Wired CT’s and 

voltage tap

Revenue    

Standard   

Single Circuit –

Wired CT’s and 

voltage tap

Revenue  

Standard 

Wireless CTs   

AMI Meters  

Electromagnetic field sensors   
NREL | 12

Conclusions

• Multiple different technology types, configurations

– With varying capital, installation, and recurring costs

• Map well to different use cases

• Determine what your goals are for the submetering before 

selecting technology and circuits
www.nrel.gov

Thank you! 

Questions?

This work was supported by the U.S. Department of Energy under Contract No. DE-AC36-08GO28308 

with Alliance for Sustainable Energy, LLC, the operator of the National Renewable Energy Laboratory, 

and the U.S. General Services Administration under Agreement IAG-14-1947. The views expressed in 

this presentation do not necessarily represent the views of the DOE or the U.S. Government. The U.S. 

Government retains and the publisher, by accepting the work for publication, acknowledges that the 

U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or 

reproduce the published form of this work, or allow others to do so, for U.S. Government purposes. 

NREL/PR-7A40-72662