EV charging columns and legal metrology

This article was first published on this site on 21/09/2023 (date of first publication) and was updated with more recent/complete content on 22/10/2023.

In the midst of the evolution of projects and products to implement the infrastructure of charging stations for electric vehicles, it is useful to clarify some often-overlooked concepts, to scale back some commonplaces, and to seize the opportunities that can follow.
First of all, do the charging stations for electric vehicles fall under the legal metrology?
Then, is it sufficient that only the electricity meter inside them is certified or not?
Finally, what are the possible certifications and the most relevant reference documents related to legal metrology?

Let us begin to delve into the subject by presenting the acronyms used when dealing with electric vehicles charging columns.

In this article, in order to refer to the EV charging column, we use the acronym EVCS in its meaning of ‘charging system’ and referring only to publicly accessible systems. The EVCSs are in fact a ‘system’ composed of various elements starting with the electrical energy meter, their beating heart, and ending with the cloud.

The EV charging columns fall under the legal metrology for several reasons. Firstly, they are used for a trade transaction against a measurement: the consumer pays money for a measured amount of electrical energy supplied to his vehicle.
Secondly, it is a system that has measurement functions based on reasons of public interest, public safety, public order, consumer protection, taxation and fair trading. These are the reasons that inspire the application of the legislation concerning the legal metrology [3].
Finally, the EVCS is a system that must guarantee not only a correct measurement, but also a number of other requirements [4]:

• prices shall be transparent, reasonable, clearly comparable, non-discriminatory and communicated in a clearly structured manner to allow end users to identify the different cost components distinguishing the price components charged by the operator of the recharging point, the applicable e-roaming costs and other fees or charges applied by the mobility service provider;
• fair market conditions among the operators;
• easily and conveniently accessibility of the user interface;
• internet connection and possibility of smart recharging, in which the intensity of electricity delivered to the battery is adjusted in real-time, based on information received through electronic communication;
• ease of payments, which means the possibility of payment by any means (cash, cards, digital apps) without the need for the consumer to enter into a contract with the operator of the recharging or refuelling point or a mobility service provider;
• secure, real-time transmission and receipt of transaction data between market players (charging point operators, mobility service and electrical energy providers, e-roaming platforms) and end consumers.

These requirements are strictly connected to the entry into force, on 12/10/2023, of the AFIR Regulation (EU) 2023/1804 (Alternative Fuels Infrastructure Regulation) [5], published in the European Official Journal on 22/09/2023. This regulation repeals the AFID Directive 2014/94/EU (Alternative Fuels Infrastructure Directive) and makes various provisions directly mandatory in the Member States, without the need for transposition; the provisions affect the entire charging infrastructure for electric vehicles, as well as that for other alternative fuels.
The requirements mentioned above are mandatorily required by this regulation, as well as being perfectly in line with the legal metrology requirements itself.

From what has been analysed so far, it is clear that the certification of the electrical energy meter alone placed within the EVCSs is not sufficient for the legal metrology purposes.
The EVCSs are expected to become full-fledged fuelling stations (electrical energy), and consequently, the approach to the metrological certification cannot longer be that of the typical household/industrial electrical energy meter used/managed by utilities for billing purposes. Here, we are dealing with a meter that is part of a more complex system and, more importantly, intended for the direct sale of an alternative fuel for electric vehicles to the public through the use of digital payment methods and apps.
Below there is a table with some application differences of the electrical energy meter as part of an EVCS or as a tool used by utilities.
Of course, the electrical energy meter of the EVCS, due to the accuracy of the measurement, is the core from which the whole delivery service starts, so it needs to be properly certified, but the transparency, the reliability and the security of the transactions, including digital ones, involving the various operators, require a broader level of certification.

Let us, now, try to shed some light and give an overview of the available certifications in Europe for EVCSs related to the legal metrology and the most relevant normative documents.
First of all, it should be noted that to date there is no mandatory certification of the full EVCS provided for and mandatory required by a European or international regulation. Each State is trying to provide for this with its own legislation to comply with, while drawing, of course, on recognized normative documents and standards used at the European and/or international level.

However, already willing to bring a state-of-the-art and properly certified EVCS as a whole to the European market, the following certifications can currently be achieved.

• Certification according to the MID Directive 2014/32/EU, Annex V (MI-003), for the solely AC/DC electrical energy meter, that is inside the EVCS. This certification is mandatory for Europe.
• Certification according to the OIML R46 ed. 2012 Recommendation for the solely AC electrical energy meter. This is a voluntary certification that allows the entry also into the international markets, after contacting the metric office of the country you wish to enter and obtaining its conversion into the national type approval. Nowadays this recommendation is under revision to include the reactive energy and the DC electricity meter.
• Certification according to the German Eichrecht law. This certification is mandatory in Germany and the related law is the only European regulation that take into consideration the whole charge system of electrical vehicles (from the electrical energy meter, to the display, the data transmission, the cloud), defining both its requirements and the conformity assessment procedure.

Generally speaking, since there will soon be European and international regulations for certification of the EVCS as a whole system, it is already possible, as well as recommended, to consider the following documents when setting up research, development, design and quality activities.

• The OIML Guide G 22 (September 2022). It considers the electric vehicle charging column as EVSE, both AC and DC, and provides measurement and technical requirements applicable to it for type approval, verification, re-verification and in situ testing.
  Although that document still does not consider the EVCS in its entirety as a system (from the electricity meter to the cloud, with everything in between), nevertheless it is an excellent basis for the design of the system itself.
  The guide aims to create an international reference regulation, so that the various national legislations can be inspired by it, realizing uniformity in EVCS certification, thus avoiding that each country develops its own legislation, which is then difficult to be harmonized.
• The German standard VDE-AR-E 2418-3-100. It contains the requirements of EVCS as a system in its broadest sense. Just because of its comprehensiveness, it will most likely be taken as a reference for the creation of a European standard.
• The legal metrology framework and guidance for electric vehicle charging stations developed by the LegalEVcharge project jointly with the NordCharge consortium. The document has a twofold content: a) the legal metrology framework for EVCS and the key points where the national implementing legislation in Europe may not be harmonised or covered by the MID Directive (e.g., accuracy classes, display specifications, data authenticity, cables, maintenance of the metrological stability, responsibility of charging operators, etc.) and gives further guidance for conformity assessment bodies, manufacturers of EVCS and charge point operators; b) guidance on metrological requirements for making EVCS available on the market and in use.

All of the mentioned documents were originated by considering the MID Directive, the OIML Recommendations, the Welmec Guides (especially those regarding the software), and the dedicated IEC, EN, CENELEC standards, as the basis of reference.

In order to better navigate through the various documents that are usually mentioned in addressing the topic of legal metrology certification for EVCSs, we provide below a summary table, which contains their title and a brief description.

Most relevant reference documents for EVCS
AFID 2014/94/EU European directive on the deployment of alternative fuels infrastructure (electrical energy, hydrogen, natural gas). It is repealed by the AFIR Regulation (EU) 2023/1804. It sets out minimum requirements for the building-up of this infrastructure in the Member States, included those for EVCS.
AFIR 2023/1804 European regulation on the deployment of alternative fuels infrastructure, and repealing Directive 2014/94/EU. This Regulation shall be binding in its entirety and directly applicable in all Member States. Published in the European Official Journal on 22/09/2023, it enters into force on 12/10/2023 and it shall apply from 13/04/2024. It sets out mandatory national targets for the deployment of sufficient alternative fuels infrastructure in the European Union, for road vehicles, vessels and stationary aircraft. It lays down common technical specifications and requirements on user information, data provision and payment requirements for alternative fuels infrastructure, included the EVCS.
OIML R46 Ed. 2012 Recommendation OIML recommendation for the international certification of AC active electrical energy meters, after converting it into a national type approval. Currently it is under revision in order to include the reactive energy and the DC electrical energy meters.
OIML Guide G 22 OIML Guide published in September 2022. It provides guidance on the metrological and technical requirements applicable to Electric Vehicle Supply Equipment (EVSE, both AC and DC) subject to legal metrological controls for type approval, verification, re-verification and in situ testing. It provides an excellent basis for the creation of each State’s national legislation. It will soon be replaced by a full-fledged recommendation exclusively dedicated to the EVCS by providing for the possibility of a voluntary certification allowing access to the international market, after converting it into a national type approval.
MID 2014/32/EU European directive on the harmonisation of the laws of the Member States relating to the making available on the market of measuring instruments. It contains also the essential (Annex I) and the specific (Annex V – MI-003) requirements to certify the AC/DC active electrical energy meters.
Eichrecht German law dated 15/08/2014 on the measuring instruments and their verification. It is composed of two normative documents: MessEG and MessEV. It contains provisions about the EVCSs intended as a whole system, so from the electricity meter to the cloud.
MessEG (Mess- und Eichgesetz) German law dated 25/07/2012, amended on 9/06/2021, about the placing on the market and supply of measuring instruments. It contains requirements for measuring instruments and rules for their verification, including those of EVCSs. It is part of the Eichrecht and takes inspiration from the MID Directive, the OIML recommendations, the Welmec Guides.
MessEV (Mess- und Eichverordnung) German executive ordinance of the MessEG. It contains its implementation guidelines on the placing and making available on the market of the measuring instruments, as well as their use and verification. It includes the EVCSs. The document is dated 12/11/2014 and it has been amended on 26/10/2021.
REA Document 6-A Document dated 16/03/2017 created by the German REA commettee, that defines rules and technical requirements for measuring instruments and auxiliary devices used for electric mobility. It includes the EVCSs as a complete system.
VDE-AR-E 2418-3-100 German standard published in November 2020 by the VDE association. It contains the requirements of the EVCS as a whole from the electricity meter to the cloud.
Practical legal metrology framework for EVCS It is the Project nr. 1539 of Euramet, defined as LegalEVcharge, in which metrology institutes from various European countries participated in order to define a legal metrology framework for EVCS (AC and DC), which is compliant with the MID Directive in respect to the electrical energy meter.
Guidance on metrological requirements for Electrical Vehicles Charging Systems Guide created on 17/12/2021 by the NordCharge consortium composed by legal metrologies authorities and notified bodies of Denmark, Finland, Norway, Sweden and Switzerland. It is intended for manufacturers, importers of EVCS and charge point operators. Its aim is to obtain a harmonised approach regarding the metrological aspects of an EVCS to ensure that products to be placed on the market meet common metrological requirements, so as to ensure transparency and reliability in measurement. The guide is a supplement to the existing legal framework in order to cover metrological requirements on EVCS to be placed on the market and to remain on it.
Legal metrology framework and guidance for electric vehicle charging stations Document dated 28/09/2021. It is the outcome of the joint work of LegalEVcharge and NordCharge. It includes both the legal metrology framework for EVCSs and the guidance on the requirements for making them available in the market and in use. The document contributes to the consumer protection and the fair trade while respecting the principle of proportionality. The document also identifies the key areas (including: accuracy classes, display specifications, data authenticity, cables, maintenance of the metrological stability, responsibility of charging operators, etc.) where the national legislation of European countries is not harmonized or covered by the MID Directive, and then provides guidance thereon.
The Electric Vehicles (Smart Charge Points) Regulations 2021 English regulations that apply to electric vehicle charging points used in home or work environments in Great Britain. It does not apply to public charging points and fast charging points.
NIST Handbook 44 Document of National Institute of Standards and Technology of United States, revised in 2023. It regulates the technical requirements necessary for the type approval of measuring instruments, including the EVFS.
NIST Handbook 130 Document of National Institute of Standards and Technology of United States, revised in 2022. It regulates and harmonizes the requirements necessary for the sale of measuring instruments, included the EVFS.

Conclusively, although the legal metrology framework for EVCSs is not yet ready and, more importantly, uniform, nevertheless the road ahead is well marked and many opportunities for manufacturers and operators can already be seized.
The public electrical vehicle charging systems are real fuelling stations, more or less digital, fully comparable to those existing for the other fuels. Definitely a major shift in the vision for the legal metrology and a challenging goal that we are all called upon to realize in the immediate future.

References
[1] See NIST Handbook 44 and NIST Handbook 130.
[2] The OIML is the International Organization of Legal Metrology, which is aimed to harmonize regulations on measuring instruments and their verification, in order to standardize them internationally so improving their distribution and metrological safety.
[3] See Decision 768/2008/CE (especially articles 1, 2 and 3), that establishes the uniform conditions for the trade of safe products in the European Union (conformity marking) within the New Legislative Framework, in which the legal metrology is included.
[4] AFIR Regulation (EU) 2023/1804 (Alternative Fuels Infrastructure Regulation) art. 5 and observations (28), (33), (34), (36), (38).
[5] Regulation (EU) 2023/1804 of the European Parliament and of the Council on the deployment of alternative fuels infrastructure, and repealing Directive 2014/94/EU of the European Parliament and of the Council. Document 52021PC0559; procedure 2021/0223(COD).