It’s been a very long time coming, but the International Standards Organisation has finally published what is formally known as ISO 15118-20:2022/Amd 1:2026. According to the ISO web site the amendment adds the following improvements to the previously published 15118-20 standard:
AC DER service, MCS service, and improved security concept
If the acronyms above seem somewhat opaque and your internet address indicates that you are located in the United Kingdom you will see this not entirely helpful notice when you click the link above, :
Sadly the associated British standard is not yet available for purchase from the BSI web site! Instead we are told:
Approval start date: 17/04/2026
Publication start date: 06/08/2026
Fortunately in all the circumstances I don’t need to wait for the BSI to start selling the document, or pay ISO CHF 227 for the original 15118-20 standard plus another CHF 227 for the new amendment. As a member of the committee that developed the standards I already have PDF copies on my hard drive.
Quoting extracts from the brief sample of the amendment provided on the ISO web site:
3.73 megawatt charging system MCS charging system according to IEC61851-23-3
3.76 distributed energy resource DER source of electric power that is not directly connected to a bulk power system EXAMPLE Generators and energy storage technologies capable of exporting active power to the electrical grid..
3.78 frequency droop curve parameterized curve of the frequency-watt function
3.87 ride-through ability to withstand voltage or frequency disturbances inside defined limits and to continue operating as specified
If you would like further insight into the implications of the above information, please do not hesitate to get in touch.
Regular readers may recall that in 2021 the British Standards Institution published the first edition of their Publicly Available Specification 1878 on the subject of “Energy smart appliances”? You may also recall that I wrote at the time:
A “smart” EV charging station is a special case of an interoperable Energy Smart Appliance.
The BSI has recently published a draft version of a new edition of the PAS 1878 specification, and is inviting comments from interested parties. Note that the deadline for submitting any such comments is July 9th 2025.
The BSI’s request for comments points out that:
This PAS specifies the following aspects of a system for the delivery of certain demand side response (DSR) services for domestic and small business premises…
This PAS is intended to be used by manufacturers of ESAs and CEMs.
NOTE 1 – Other audiences that might have an interest in this PAS are maintainers of ESAs, manufacturers and maintainers of interfacing products, software developers and service providers.
The introduction to the new draft includes the following information:
This is a full revision of the document, and introduces the following principal changes:
defined system architecture for both on-premises and hybrid cloud/on-premises implementations of ESAs and CEMs, and both 1-to-1 and 1-to-many CEM to ESA connections;
minimum requirements for secure communication between CEMs, ESAs and DSRSPs;
detailed sequence of DSR-based activities from consumer registration to decommissioning;
a move from OpenADR 2.0b to OpenADR 3.0 as the minimum application layer protocol to be supported by Interface A (between DSRSP-CEM);
the optional provision of flexibility performance requests from the DSRSP to enable ESAs to calculate relevant flexibility offers more easily;
updated compatibility with GB smart metering and a wide range of smart appliances – including EV charge points and battery storage;
new provisions for Open ADR 3 as the Interface A
By way of a brief introduction to some of the assorted acronyms mentioned above, here is figure 1 from the draft PAS:
Clause 8 of the draft PAS includes these specific requirements regarding electric vehicle charging:
The smart EV chargepoint ESA shall be capable of reporting forecast power profiles based on operating capabilities, consumer preferences, including expected departure/arrival schedule and journey distance/ duration/characteristics, and external information, including estimates of EV battery capacity, EV state of charge (or state of charge if available via the charger – e.g. V2G, or accessible via the vehicle telematics) and EV physical operating limits. If a smart EV chargepoint supports V2G functionality and has been configured to present itself to the DSRSP as an ESA, it shall meet the information and messaging requirements specified in Clause 5 and Clause 6.
NOTE Smart EV chargepoints are not required to support V2G functionality.
Clause 5 is entitled “Communications and messaging” and includes this diagram:
Clause 6 is entitled “Cyber security” and includes this diagram:
If you have any questions please do not hesitate to ask using the space provided for that purpose below.
How do you catch a cloud and pin it down? How do you find a word that means Flexibility?
We’ll get back to answering that question in due course. First some exciting news.
On November 22nd I attended the kick off meeting of a new International Electrotechnical Commission “smart grid” committee. This one is catchily entitled the “System Committee Smart Energy ad hoc Group 11 on Energy flexibility and residential DSR: common ground”, or “SyC SE ahG 11” for short.
If you follow the link just above you will discover that ahG 11’s mission is:
To consider the implementation of international residential flexibility system standards, their compatibility with national requirements, and propose best practice:
* To ensure the compatibility of end-to-end system solutions at international level,
* To identify emerging challenges related to the uptake of residential DSR,
* To consider terminology alignment, and
* To develop an accelerated report containing requirements for residential flexibility. This would give recommendations for alignment of existing national publications and flexibility projects under development with international standards. It would also identify, if relevant, the need for further standardization
Amongst other questions discussed at the kick off meeting was “How do you define the term ‘flexibility'”. Your mileage may vary of course, but since I spent 5 years of my life meeting 2 or 3 times per week on the committee developing the IEC 63110-1 document I will quote from the Committee Draft for Vote (CDV for short) of that international standard:
General concept of elasticity of resource use, (demand, storage, generation) modification of consumption and/or generation of energy/power, on an individual or aggregated level, in 371 reaction to an external signal (price signal or request) in order to provide a service within the energy system
Elasticity of resource use (demand, storage, generation), modification of consumption and/or generation of energy/power, on an individual or aggregated level, in reaction to an external signal (price signal or request) in order to provide a service within the energy system.
If you have strong objections to that definition please do not hesitate to join ahG 11, or failing that to send your preferred term of words to me so that I can bring it to the committee’s attention.
My other main action item before the next meeting in the New Year is to generate a list of existing standards, regulations etc. relevant to my particular area of expertise, which is bi-directional power transfer during electric vehicle (dis)charging (BPT for short). More commonly referred to as V2x. Since ahG 11’s term of reference includes the word “residential” this suggests an emphasis on vehicle-to-home technology (V2H for short) . However, homes are of course connected to the local electricity distribution grid, and are not forbidden from feeding electrical energy back into the grid as long as all the associated rules and regulations are adhered to.
Please let me or any other member of the committee know of any “standards” within your own area of expertise that may be relevant to “residential demand side response” (using the UK’s non standard nomenclature!), whether they be international, national, “industry de facto” or even the learnings from relevant “pilot projects”.
Please feel free to suggest candidates for “standards” for communicating across any of the arrowed lines in the diagram, and alternative diagrams for that matter!
Today’s article is another in our occasional series endeavouring to explain the arcane world of international standards. Hence it is more technical than is usual here on the V2G UK blog, but it is possibly even more relevant than the latest V2x announcements from assorted electric vehicle manufacturers.
This morning I attended the first meeting of an IEC Technical Committee 69 Joint Working Group 11 task force set up to develop an “information document” aiming to provide helpful advice to EV charging station manufacturers as they develop future “smart grid” enabled products. This document will be more like the British Standards Institution’s recently released PAS 1878 “specification” than a full blown international standard, albeit hopefully nowhere near as long!
By way of an example of the sort of things that were discussed in the meeting here is an infographic from PAS 1878 which hopefully illustrates the extensive overlap between the BSI’s concept of a future “smart home” and the related concepts emerging from the work of the European CENELEC Technical Committee 205 and other standards development committees:
PAS 1878 figure E.1. (Click to enlarge)
As annex E from the PAS explains:
This annex provides information on the relationship between the functional architecture described in this PAS and an amalgamation of the “smart grid” functional architecture included in several CENELEC and IEC standards. The representations in the CENELEC and IEC documents, whilst broadly similar, do differ slightly, hence the need for an amalgamated representation. The two architectures and how they are mapped are shown in Figure E.1. The CENELEC/IEC architecture is configured assuming that the CEM is internal to the consumer premises. As this is a functional architecture, a configuration with the CEM external to the consumer premises (e.g. in the cloud) is also permissible.
Figure E.1. shows the relationship between the PAS 1878 functional architecture and an amalgamated representation of the smart grid flexibility functional architecture depicted in several CENELEC and IEC standards, including BS EN 50491-12-1:2018, BS EN 50631-1:2017, PD IEC/TR 62746-2:2015, and prEN50491-12-2.
Expect to hear much more over the coming months and years about such esoteric things as the “Customer Energy Manager”, the “Resource Manager”, assorted “Demand Side Response Service Providers” and any number of other novel terms and acronyms. The diagram above is generic, but for the EV charging use case note that the charging station is equivalent to the “Smart Appliance” and the OCPP and/or IEC 63110 protocols are equivalent to “Interface B” in the top half of the diagram or the “Manufacturer protocol” in the lower half.
Hopefully that’s all crystal clear by now? If not hopefully it will become so by the time the newly constituted IEC task force has completed it’s work and you have read the resulting guidance document!
The British Standards Institution has just published a new “specification”, and unlike most BSI “standards” this one is free to download, as long as you don’t mind parting with an email address. As the download page puts it:
BSI is working with the UK Government to encourage the uptake of safe, secure and interoperable Energy Smart Appliances (ESAs). These are needed for the active management of demand on the electricity network, known as Demand Side Response (DSR). PAS 1878 is a critical component in this because it details the requirements and criteria necessary to make an energy smart appliance compatible with DSR activities.
At this point you may have a couple of question, such as “What on Earth is a PAS?”. The BSI have a ready answer for that question:
A PAS (Publicly Available Specification) is a fast-track standardization document – the result of an expert consulting service from BSI. It defines good practice for a product, service or process. It’s a powerful way to establish the integrity of an innovation or approach.
The next obvious question is “What has this got to do with electric vehicles and/or vehicle-to-grid technology?”. The answer to which is that a “smart” EV charging station is a special case of an interoperable Energy Smart Appliance. As the foreword to PAS 1878 states:
Please read on to discover the latest news from the smoke filled back offices of the International Electrotechnical Commission’s (IEC for short) electric vehicle standards development committees.
Here once again is the roadmap for the development of the IEC 63110 international standard defining a protocol for the management of electric vehicles charging and discharging infrastructures:
Part 1 of the standard (IEC 63110-1 for short) concerns itself with potential EV charging and discharging use cases. As we have previously mentioned the committee produced a draft document for comment many months ago. The original draft has now been modified to incorporate the suggestions contained in several hundred comments received from around the world. A grand total of zero of those comments emanated from the United Kingdom. The committee is issuing one final call for informal suggestions for further vehicle-to-grid use cases before their next face to face meeting which will be held in Seoul, South Korea starting on June 18th 2019. At that meeting the Committee Draft for Vote (CDV) document for 63110-1 will be finalised, following which the assorted national committees that make up the IEC will vote on the committee’s proposals.
Meanwhile the IEC 63110 part 2 (IEC 63110-2) task force looking into possible options for “message encoding and transmission technology” to be included in the standard are also currently completing their work. It was agreed on the IEC Technical Committee 69 Joint Working Group 11 (TC 69/JWG 11 PT1 and PT2 web conference calls earlier this week that the Seoul meeting should be extended by a day in order to finalise this aspect of part 2 of the standard. By way of example, version 2 of the Open Charge Point Protocol (OCPP 2.0) specifies using JSON encoding over RFC 6455 WebSockets transport, but the task force have been considering a wide range of other possibilities.
Should you have any thoughts on these thorny eMobility topics then please do not hesitate to get in touch at your earliest convenience. After the TC 69/JWG 11 meeting in Seoul these matters will be starting to be set in stone (SSS for short).
In our continuing endeavour to explain the arcane workings of the International Electrotechnical Commission’s (IEC for short) electric vehicle standards development committees we have some exciting news to report!
it was agreed at the IEC Technical Committee 69 Joint Working Group 11 (TC 69/JWG 11 for short) meeting in Toronto last week that work on the IEC 63110 part 2 standard (IEC 63110-2 for short) should begin by setting up a task force (TF for short) to “evaluate possible options for message encoding and transmission technology”. We swiftly volunteered for the new task force, not least because our V2G EVSE subsidiary is already evaluating precisely that for the United Kingdom’s Department for Transport (DfT for short).
In actual fact the Project Team 1 (PT1 for short) schedule has slipped a bit, so if you still have any out of the ordinary new “protocol for the management of electric vehicles charging and discharging infrastructures” use cases to bring to our attention there is still time before the Committee Draft (CD for short) stage of the IEC process is reached. In addition if you have any suggestions for “message encoding and transmission technologies” above and/or beyond the industry standard TCP/IP over cellular comms please do not hesitate to get in touch.
Lastly, but certainly not least, the existing IEC 63110 Security Task Force is still seeking input from suitably qualified experts in that particularly important domain.
Our regular reader(s) will be aware that quite some time ago I suggested that:
There’s a few more urgent things to be ticked off on the to do list. How about OCPP 2.0 or even fully fledged British and international standards for “smart charging”, V2B and ultimately pukka V2G protocols for starters?
I am happy to now be able to report that my wish has come true! An international standard is now being developed for electric vehicle supply equipment (EVSE for short) communications with the “back office”, including vehicle to grid (V2G for short) functionality. For my sins I now sit on IEC technical committee 69 joint working group 11 (TC69/JWG11 for short). According to the Wikipedia article on the subject, which I wrote:
IEC 63110 is an international standard defining a protocol for the management of electric vehicles charging and discharging infrastructures, which is currently under development. IEC 63110 is one of the International Electrotechnical Commission’s group of standards for electric road vehicles and electric industrial trucks.
You will no doubt be delighted to discover that proceedings are still at a fairly early stage. Here’s the current IEC 63110 roadmap:
The top line indicates to the initiated that I am still able to point out that IEC TC69/JWG11 is currently seeking submissions for potential use cases to add to our initial list. The current deadline is December 6th. It is probably safe for you to assume that all the obvious stuff from the Open Charge Alliance’s Open Charge Point Protocol and ISO/IEC’s 15118 protocol is already included on our list.
However if you have a use case that isn’t in amongst the obvious stuff then please do not hesitate to get in touch!
