Update on NIST Activities for EVSE

NIST OWM is striving to assist the weights and measures community meet the new technical challenges and demands of America’s continued transition to E-mobility. While OWM continues to facilitate standardization of commercially applied EV supply equipment (EVSE) in the U.S. through technical analyses and leadership of the National Working Group on Electric Vehicle Fueling and Submetering, it has recently expanded its efforts to new scientific and international initiatives. These activities shall also help advance the burgeoning framework for ensuring sound EV charging infrastructure and equity in the market. 

In one key instance, the OWM is partnering with scientific experts of the NIST Applied Electrical Metrology Group to develop a new measurement standard for high-power DC electricity. This much-needed resource is a bespoke transfer reference meter that will metrologically underpin commercial transactions for DC Fast Charging. Notably, the NIST transfer meter will be used to calibrate DC electricity field testing equipment used by state weights and measures officials to verify EVSE meter accuracy and establish traceability of their results to the International System of Units (SI).

OWM is working with several international partners, including the National Metrology Institutes of Germany (PTB) and Switzerland (METAS), to test and verify the NIST transfer meter. This interlaboratory study not only substantiates the linkage of the DC electricity standard to the SI but will also bolster the U.S.'s position as a global leader in the deployment of quality EVSE. High-power DC fast charging is a rapidly growing market sector that is vital to wider EV adoption. Field enforcement of the metrological rigor of EVSE by weights and measures officials will go a long way to instill the trust of both consumers and providers. 

OWM is also deeply engaged in the international legal metrology community while it develops standards and reasonable regulations for commercially applied EVSE. The principal forum for this activity within the International Organization of Legal Metrology (OIML) is OIML Technical Committee (TC) 12/p 3, the project group that produced 2022 OIML G 22 Electric Vehicle Supply Equipment (EVSE)- Metrological and technical requirements- Metrological controls and performance tests. This project group is currently working to revise and expand the Guide to a full OIML Recommendation, or model law. Within the OIML community, the OWM aims to represent US manufacturers of EVSE and EVSE testing equipment, while also exploring ways the Recommendation can be harmonized with U.S. and state regulations. Relatedly, OIML is also beginning work through a new TC 12/p 4 (with U.S. as the convener) to develop a new Recommendation on DC electricity meters. This project is anticipated to provide further performance guidelines for manufacturers whose devices are used in EVSEs. 

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Please also check out the new Electric Vehicle Supply Equipment (EVSE) FAQ page for more information on these topics and other important weights and measures matters concerning EVSE.