EE Reports Metering 101a: How Submetering Works

The Metering GuideMetering 101a:

How Submetering Works

A Companion guide to Metering 101; Detail on how submeters work, selecting the right meter, and questions to ask before installing

Metering 101 recap: benefits of submeters

Benefit 1 Track and

Optimize Energy Usage

Benefit 2 Tenant Specific Billing

Benefit 3 Fault

Detection Benefit 4 M&V for New

Systems Savings

Benefit 5 Demand Response & Dynamic Pricing

Programs

Submeters Are The Solution

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Proprietary & Confidential


Revenue Grade Meters Allows building owners to charge tenants for individual utility use Allows for participation in utility / market programs Will most likely use solid core or split core current transformers (CT’s)

– More expensive– Slightly more accurate data

Non-Revenue Grade Meters Allow building owners to gain better understanding of energy usage to take informed action No access to demand response programs or individual rates for tenants Will most likely use rope or split core CT’s

– Cheaper, easier to install– Less accurate data

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Different types of submeters for different applications

Revenue grade meter picture source: SolrenView (AltEstore.com)Non-Revenue grade meter picture source: Northern Design

Proprietary & Confidential3

How do submeters work?

Picture sources: Pike Research, Electricity Submeters, 2012 and Locus Energy


1) Submeters hook up to electric or other utility meters and panels using current transformers (CT’s)

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2) Building owner chooses specific systems to be submetered (lighting, heating, cooling, refrigeration, tenant area, etc.)



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3) Submeters allow for data acquisition and management to go directly to building owner, facility manager, etc. via a BMS or SCADA system



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Information kiosk


3) Submeters allow for data acquisition and management to go directly to building owner, facility manager, etc. via a BMS or SCADA system

4) Instant access on PC, smart phone, or even a lobby kiosk


Utility meter pulses– Readout of utility meter to determine quantity of kWh or other energy type used every ~1-15 minutes• Show fluctuations of usage throughout day• Typically provided by utility companies as an input to a BMS or Logger

Submeter Readings Using Modbus– Give more detailed readouts of energy usages (kWh, Amps, Voltages, Harmonic Distortions, etc.)– Communication protocol that connects to BMS– Can determine when an individual asset is near end of life, needs repair, etc.

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In depth look at submeters (Part I)

Picture source: http://emon.com

BMS SYSTEM

ENERGY SOFTWARE


BACnet– Similar communication protocol to Modbus but newer technology– Allows for communication between BMS appliances of different companies

Auxiliary functionality of meters– Digital Input: reads other meters and systems by counting pulses per kWh (or gallons, cfm, steam, etc. depending

on utility)– Analog input: reads temperatures, etc. of systems– Digital output: allows for manual thresholds (keep system under/over certain amount of kWh)– Analog output: feed information into BMS or SCADA system to determine whether to shut systems off/on, ramp

up/down

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In depth look at submeters (Part II)

Picture source: http://www.kmccontrols.com


What is the install for? What does the building owner want to know and do with the data? – kWh, kW, amps, voltage, etc.– Tenant billing, M&V, etc.– Will help determine revenue grade vs. non-revenue grade

How does the owner want to communicate with the submeter?– Ethernet, wireless, hardwire, etc.– Facility manager or third party operator analyzing data– Where is the nearest connection port?

What size CT’s can be attached and installed?– Size of wires determines solid-core, split-core or rope CT’s– Access to wires within panels / electric room, building code adherence, etc.

Which loads are to be metered?– One or three phase loads, make sure to connect CT’s to right phase off of meter

How do the submeters connect to one another for overall BMS / SCADA?

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Basic questions to ask before install


Find a contractor for your state / city– NYSERDA helps this process for New York,

similar setups in each state

– TRC Solutions will help almost any state• Will help determine best system size and

placement• Will assist with applications for incentives

and financing options• Will assist in all necessary documentation

and paperwork

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How to get involved

Become a state approved contractor– NYSERDA helps this process for New York,

similar setups in each state

http://www.nyserda.ny.gov/Contractors/Find-a-Contractor

http://www.trcsolutions.com/locations

http://www.nyserda.ny.gov/Contractors/Find-a-Contractor

Proprietary & Confidential04/18/2023

ABBCARMAContinental Control SystemsDaiichi ElectronicsEatonEchelonElsterEZ MeterGeneral ElectricHoneywell & E-Mon ISTA Itron Janitza Electronics

LevitonLEMMitsubishiNorthern DesignObviusOsakiPanoramic PowerQuadlogicSchneider ElectricSCIenergySiemensToshiba Totko Meter SystemsTriactaYokogawa Electric

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Key industry players

For your consideration, the following companies are creating the newest and most advanced submeters:

For more information, email us at [email protected] visit our site eereports.com

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EE Reports Metering 101a: How Submetering Works