The charging stations' backend protocol OCPP will evolve - through Oasis and IEC

Marc Mültin
Marc Mültin
August 9, 2016
• Updated
min read
The charging stations' backend protocol OCPP will evolve - through Oasis and IEC

How will OCPP evolve with Oasis and IEC now involved.

The Open Charge Point Protocol (OCPP), launched by the Open Charge Alliance, an industry alliance of public and private charging infrastructure providers, is the most widely used communications protocol between charging infrastructure and charging operators. Its further development will now take place in an official standardisation committee. Here, the standardisation of such charging infrastructure backend protocol starts on two tracks, both through the American OASIS as well as through the European IEC. I explain the background to this in this article.

According to information from the OCA, OCPP has established itself as the de facto standard and is already used in 78 countries around the world. There are now several reasons why the further specification of the protocol, currently available in version 1.6, should be handed over to a standardisation committee:

  1. An increase in confidence and a higher acceptance rate through the seal of a standardisation organisation
  2. The adjustment or alignment of existing standards such as IEC 61851, IEC 61850, ISO 15118 and relevant RFCs (request for comments)
  3. Use of best practices for creating and maintaining an international standard

This raises the question as to which standardisation body should be selected for this purpose? The committees, which immediately come to mind and which are widely used in Europe, and are internationally recognised, are ISO (International Organisation for Standardisation) and IEC (International Electrotechnical Commission). While the IEC develops and publishes international standards for electrical, electronic and related technologies, the focus of the ISO is on international standards in all areas except for the electrical and electronics areas. Sometimes standards are also jointly developed by ISO and IEC in the form of a so-called joint working group (JWG), as has been done or is being done, for example, with ISO/IEC 15118, since the two domains of information technology and energy technology merge here. Regarding publication, there was a decision between ISO and IEC not to publish an ISO/IEC standard ("Dual name standard') but a so-called "Dual logo standard". With this, ISO is the leading publisher, but the standard is also available with an additional IEC logo at IEC. Therefore, one speaks now actually more about the ISO 15118 instead of the ISO/IEC 15118 (thanks again to Stephan Voit, for pointing this out).

From the OCA's point of view, however, there is still a third standardisation organisation emerging from the USA, the OASIS (Organisation for the Advancement of Structured Information Standards). The OCA has now agreed on OASIS, in a first step for the further development of OCPP to version 2.0. As far as I know, this has to do with a faster development cycle with OASIS (planned by the end of 2017), as opposed to IEC (normally 3 to 4 years) as well as with the hope of being able to act with less industrial politics and thus more quickly. In a next step, the OCA plans to simply integrate the OCPP 2.0, developed by OASIS, into the IEC and, in the best case scenario, to get only one seal from the IEC with a minimum of time - it is rather questionable as to whether the process will be so easy.
A so-called liaison will be established for cooperation between OASIS and IEC, which means that experts from both committees exchange information regularly and thus the best possible knowledge transfer is ensured.
A rough schedule for the work within the scope of the OASIS and the IEC can be likewise taken from the published presentation.

In contrast to version 1.6, version 2.0 will now be restructured in accordance with the guidelines of a standardisation document. In addition, security mechanisms such as encrypted communications and thus also secure firmware updates among others should be finally integrated. Furthermore, it is of course essential that the necessary parameters for the transmission of information for ISO 15118 communication be introduced. In the previous draft, the preliminary work for tariff tables (SalesTariff) has already been done to my knowledge, but no messages have yet been provided for the exchange of certificates and thus the installation or updating of digital contract certificates. Maybe this is still to be integrated into OCPP 2.0, but possibly only in a kind of OCPP 3.0 in the scope of the IEC. Last but not least, further features for the better monitoring of a charging station are to be introduced and the alignment with standards for a demand response is to be advanced.

On July 27, OASIS officially published a "Call for Participation", calling on all companies, organisations and individuals who are interested in the further development of this protocol (a standard) to participate actively. However, the participation is of course linked to membership in OASIS, which also requires a corresponding financial contribution. A first conference call or web meeting of the Technical Committee will take place on 7 September this year. For further information on participation in this OASIS Technical Committee, please contact Carol Geyer (
I am a member of both standardisation bodies and will therefore take part in the discussions.

The Company RWE International SE (since April 2016 known under the new name 'Innogy SE'), which is a member of the Board of OCA, however, has greatly promoted the IEC standardisation committee from the very start, because from the perspective of RWE, such a communication standard, which relates to a safety-critical electrical field would be ideally positioned at the IEC. As it so happens, the standardisation process was initiated at the IEC at relatively the same time. At the beginning of such a process there is a so-called New Work Item Proposal (NWIP), which was distributed to the corresponding mailing lists at the end of June this year. Unfortunately, I cannot upload this document here, but I can still talk about the content.

In a presentation preceding this NWIP, the proposal was already in existence under the name "EMIOP - Electric Mobility Infrastructure Open Protocol", which is used in the current NWIP parallel to the new document heading "Management of Electric Vehicle Charging and Discharging Infrastructures". The standardisation proposal foresees a document family consisting of three parts:

  1. Part 1: Basic Definitions and Use Cases
  2. Part 2: Technical Specifications and Requirements
  3. Part 3: Requirements for Interoperability Tests

Thus, in the first document, the basic conceptual definitions are to be created - as usual in such a series of standards - and use cases described before the second technical document specifies the technical specifications regarding messages to be exchanged, message formats, and the communication protocol itself with its sequence diagrams and the associated requirements.
These requirements can then be translated into test cases with the help of the third document, so that appropriate implementations of this standard can be tested for conformity to the standard using a test suite still to be developed. The standard series of ISO 15118 is indeed similarly constructed.
By the way, "electric vehicles" as used here is intended to include trucks, buses and boats or ships, in addition to battery-powered electric cars (BEV) and plug-in hybrids (PHEV).

Cable-connected (AC and DC) as well as wireless energy transfer as well as all charging modes, defined in the IEC 61851, are to be considered. The following features should be included in the protocol development:

  • Management of the charging station (controlling, monitoring, maintenance, firmware updates and configuration profiles)
  • Authentication, authorisation and processing of payment processes
  • Provision of the relevant data for roaming and supplying tariff signals and smart meter values
  • Charging control for the purposes of management of a charging session and the energy flows
  • Reporting (status updating as well as presumed energy flow and network state data as well as contract data - hopefully anonymised or pseudonymised, at best only concerning the provider - for statistical purposes)
  • Provision of other e-mobility services (keyword: value-added services)

In reference to the European mandate "M/490 - Smart Grid Information Security", the requirements for information security, data minimisation and reliability in such a critical infrastructure system should of course not be disregarded in this case.

Contact person responsible for this proposal is Stephan Cater ( from innogy. The relevant technical committee is actually the IEC TC69 (Electric road vehicles and electric industrial trucks), which seeks to cooperate with the IEC TC57 (Power systems management and associated information exchange).

All in all, this standardisation initiative is intended to counteract the current wild growth in various backend protocols (e.g. the early proprietary protocols of the first charging infrastructure providers, the OCPP developed by the latter, or the LG2WAN propagated by RWE) and to speed up an alignment or interoperability with already developed standards. The aim here is to turn the 'de facto' standard into a truly mature standard, which is best accepted and uniformly applied throughout the world.

Being part of the scope of the DELTA research project, an active participation in the IEC standard by some members of the project (including me) is guaranteed, as this is already an item in one of the defined work packages. Since the research project will run until the end of 2018, there is enough time to secure the work on the standard with the appropriate personnel.

Marc Mültin
Marc, the Founder and CEO of Switch, has over 13 years of experience in the e-mobility space and holds a PhD in Computer Science. He is the leading global expert and co-author of international EV communication standards (ISO 15118 & OCPP 2.0.1) that underpin the Switch platform.
Connect with
Marc Mültin

Related reads

Latest News