1. EVSE Embedded Submetering & Communication Kenneth Brown, Leviton Manufacturing

2. Who is NEMA?
NEMA is the association of electrical equipment and medical imaging manufacturers, founded in 1926 and headquartered in Arlington, Virginia.
400-plus member companies
Manufacture diverse set of products power transmission and distribution equipment, lighting systems, factory automation and control systems, and medical diagnostic imaging systems.
The U.S. electroindustry accounts for more than 7,000 manufacturing facilities, nearly 400,000 workers, and over $100 billion in total U.S. shipments.

3. Electric Vehicle Supply Equipment (EVSE) Section
NEMA Electric Vehicle Supply Equipment/Systems Section represents manufacturers of products or assemblies installed for the purpose of safely delivering and managing electrical energy between an electric vehicle and an electrical source.
Purpose:
Market Development
Education
Technology, application, and product standards

4. EVSE Section Members

5. Key Drivers of Submetering
To enable separate EV charging rates
National Conference on Weights and Measures (NCWM) NIST Method of Sale Regulation for retail sale of electricity as vehicle fuel (publicly accessible)
To enable power monitoring for non-commerce applications

6. Purpose of the Guide for Embedded Metering and Communication
The purpose is to provide guidance for EVSE’s that include a metering function
The EVSE incorporates a communication protocol access to metering data
Where codes, standards and regulatory documents relative to EVSE metering exist, the guide will harmonize with those standards
The guide will develop standards where requirements do not already exist

7. The Scope
North American types of EVSE embedded meters used in commerce and non-commerce applications
The guide addresses different capabilities, installations and certifications
Tiered functionality for embedded meters including tamper resistance, accuracy, calibration, communication, security, and reliability
AC and DC charging EVSEs

8. Key Issues for the Guide
Commerce versus Non-Commerce EVSE requirements:
Accuracy Requirements – acceptance of proposed requirements by NIST and utilities for billing
Distinction of requirements for Embedded EVSE versus separate submeters
Metering configuration options for an EVSE 

9. National Conference on Weights and Measures
Professional nonprofit association of state and local weights and measures officials, federal agencies, manufacturers, retailers and consumers
From fuel pumps to toilet paper
Goal: uniformity in W&M laws and regulations among states and local jurisdictions to facilitate trade, fair competition, consumer protection
NIST is NCWM partner and maintains relevant Handbooks

10. Method of Sale Regulation
Handbook 130 governs method of sale
Requires retail sale of electricity as vehicle fuel to be done by energy measure (kWh, MJ)
Metering required

11. National Conference on Weights and Measures
Handbook 44 governs technical requirements for measuring
Provisional Key Agreements
Targets EVSE embedded metering only. A “submeter” document may be needed later
Accuracy defined and tested at coupler. Compares calibrated tester reading with display indication. Little or no ANSI C12 requirements would apply

12. National Conference on Weights and Measures
Handbook 44 Provisional Key Agreements (cont.)
Tamper proof: seal and audit trail for metrological components
No printers, coin operations, field calibration
Energy units: kWh only
Billing: kWh and/or time
Billing & Audit Information available electronically

13. NEMA Standards Activities
Monitoring consumer EV charging habits is direct monitoring of charge time & power consumption
The cost of an embedded meter is low relative to the infrastructure costs required to add a separate submeter
The EVSE can send meter data to a remote location for storage and developing billing information
EV users will know what they’re paying to charge their vehicles

14. NEMA Standards Activities
NEMA is developing a guide to identify existing requirements and provide recommendations for embedded metering
The guide recommends a tiered functional approach for embedded meters including tamper resistance, accuracy, calibration, communication, security and reliability.
The guide will recommend accuracy, test and calibration requirements for the EVSE embedded metering
Key performance standards related to embedded EVSE include: UL 2231 & 2594, SAE J1772, and ANCI C12

15. NEMA Standards Activities (cont’d)
The new “Guide for EVSE Embedded Metering and Communication” encompasses the North American types of meters emerging within EVSEs
The stakeholders expected to benefit from the new Guide are EVSE manufacturers, utilities, automakers, smart meter manufacturers, EV drivers, EVSE owners, and regulators
The guide will describe methods of test and determining accuracy of commercial EVSEs with embedded meters by measuring the performance at the charge connector
The working group has identified gaps in existing standards and is working diligently to close the gaps through development of new processes and procedures

16. Commerce EVSE Embedded Metering System
LAN
Charging provider
Utility
EVSE with Meter
Provider billing.
Utility demand response requests.
V2G requests
Customer Billing
Energy
Communications
NEMA EVSE Embedded Metering Scope

17. Non-Commerce EVSE Embedded Metering
Total energy usage, EV energy usage data, DR, VTG requests MM
LAN
Utility web site
Utility
energy use monitoring
EVSE with Meter
Billing to customer = Total energy used – rate discount for EV usage.
Energy
Communications
NEMA EVSE Embedded Metering Scope

18. Questions? Thank You! Kenneth Brown, Leviton Manufacturing