Project Ultra-E realises key public infrastructures are needed for Plug & Charge

Marc Mültin
Marc Mültin
September 18, 2017
• Updated
min read
Project Ultra-E realises key public infrastructures are needed for Plug & Charge

The issues with EU-funded research project Ultra-E  - and what does it mean?

We all know that the rise of e-mobility closely links to a charging infrastructure which is readily available, reliable, and sufficient regarding the number of charging stations installed. These are the primary concerns of those who asses for themselves if it is worth buying an electric vehicle (EV) or not. At the same time, we need to make sure that the business process of secure and tamper-free charging and billing is carefully addressed by all involved e-mobility market players, including automotive OEMs, charge point operators (CPOs), mobility operators (MOs, aka e-mobility service providers) and IT infrastructure providers. The challenge is to establish a smoothly running system which is secure, user-convenient, reliable, and interoperable between the participating actors.

This article sheds light on the ongoing activities in the EU-funded research project Ultra-E that sets out to tackle the issues as mentioned above.

ULTRA-E – A corridor of high-power charging stations across Europe

The primary goal of Ultra-E, a project co-funded by the European Union, is to establish a European-wide corridor of high-power charging stations. The project has a total budget of around 13 Mio Euros. It started off in 2016 and will proceed to the end of 2018. The Ultra-E project website still only provides rudimentary information, but I was told that more is in the pipeline. In total, 25 so-called Ultra-Fast-Chargers shall be installed on a corridor of more than 1.000 kilometres, with a maximum distance of 120 – 150 km between each charging site. Twelve of those chargers will be installed in Germany, five in the Netherlands, four in Austria, and four in Belgium. The chargers shall be able to reduce the charging time needed for a travel distance of 300 km from 1.5 hours to 20 minutes, thereby providing charging powers of up to 350 kW per charging station.

Project goals ISO 15118 and Plug & Charge

One of its project goals is to define the architecture and needed functionality for applying the ISO 15118 communication standard in real life and thereby realising the user-convenient Plug & Charge functionality for seamless authorisation, billing, and load control. With Allego in the lead, Ultra-E involves big players in the e-mobility and automotive industry, such as Audi, BMW, Renault, Hubject, Magna, and Smatrics.
As the implementation of ISO 15118 on a larger scale is one of the key technical challenges, this project is the first to realise the newly published VDE regulation VDE_AR_E_2802-100-1 that clarifies the "Handling of certificates for electric vehicles, charging infrastructure and backend systems within the framework of ISO 15118".
You may ask what the VDE is if you have never heard of this association. Well, the VDE Association for Electrical, Electronic & Information Technologies (German: Verband der Elektrotechnik, Elektronik und Informationstechnik) is one of the largest technical and scientific associations in Europe. Its activities include ensuring safety in electrical engineering, developing recognised technical regulations as national and international standards as well as testing and certifying electrical and electronic devices and systems.

ISO 15118 only defines the communication between electric vehicles and charging stations. To ensure a secure exchange of information for this machine-to-machine communication, we need to establish some degree of trust. This trust relationship builds upon the exchange of digital signatures and certificates that prove the identity of a communicating party - such as an EV or a charging station. Those digital certificates are based on Public Key infrastructures (PKIs). A PKI is a set of roles, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates. The principal idea of what kind of PKIs are required is already written down in the ISO 15118 standard.

A VDE regulation for realising the needed Public Key Infrastructures

However, if there are no such PKIs established in the market to bring the complete Plug & Charge experience to life, then it's as if you built a brand-new and fascinating car - but forgot to put the engine in it. In order for the Plug & Charge functionality to work, we need to make sure that a so-called contract certificate that is linked to a legal charging contract from the mobility operator of your choice can be installed in the EV. This can be done either via the charging infrastructure during a charging process or a telematics link of the automotive OEM. That contract certificate, together with a digital signature (ECDSA), enables the EV to automatically authenticate itself for charging as soon as you plug in your charging cord or park above a wireless charging pad. Charging, billing, load control - all done without any further action needed from the driver (thus the expression “Plug & Charge” or “Park & Charge”).
The process of provisioning such a contract certificate involves a set of e-mobility market stakeholders that need to collaborate via well-defined interfaces to exchange the necessary cryptographic key material and digital certificates.
And that’s exactly what VDE_AR_E_2802-100-1 is all about: it fills the missing specification gap of ISO 15118 to realize this user-convenient Plug & Charge feature.

ISO 15118 Masterclass - helps you to understand the VDE regulation better

In my ISO 15118 Masterclass, published in February 2017, I provide a "Plug & Charge Video Tutorial" which helps you to understand the necessary business processes, IT infrastructure components, interfaces and implementation details addressed by the VDE regulation VDE-AR-E-2802-100-1.

Back in February, the VDE regulation was not yet published, but as I am head of the expert group which has been defining this regulation over a couple of months, I know exactly how it works. Back then I already believed that the industry deserves to be informed about this specification as soon as possible so this technology can be properly implemented in the market and be ready to meet consumer demand.

Luckily, the VDE regulation has finally been published on September 15th and can now be purchased via the website of the VDE publishing house
So far, it is only available in German. However, the document has already been translated into English. After the review process is finished, this standard will also be available in English. I hope that the official publishing process will not take longer than a few weeks maximum.

ULTRA-E implements Plug & Charge according to VDE-AR-E 2802-100-1

Some of my clients are members of the Ultra-E project. That allows me to help and guide them while setting up the IT infrastructure and interfaces needed to finally make the last missing piece of the ISO 15118 puzzle available in the market. 
Currently, only Daimler’s Smart electric drive and Innogy SE’s charging infrastructure support ISO 15118. However, the support of ISO 15118 is to some degree limited as long as the necessary PKIs are not yet deployed in the market. One can imagine that at least Audi and BMW, being part of this research project, will soon follow with ISO 15118-compliant EVs – my bet is either 2019 or 2020. They are also very likely to offer e-mobility services themselves and thereby contract certificates that are linked to their own charging contracts. As the after-sales market gets more and more important in the era of e-mobility and autonomously driving cars, this is a natural evolution of the product portfolio offered by automotive OEMs.

A central role in this project plays Hubject, an eRoaming platform that provides a digital B2B marketplace for services related to the charging of electric vehicles. They decided to broaden their product portfolio by implementing many of the roles defined in the VDE_AR_E_2802-100-1 regulation. For example, they operate so-called certificate authorities (CAs), such as the trust anchor V2G (Vehicle-to-Grid) Root CA, that sign certificates for e.g. CPOs, MOs or automotive OEMs. This is an essential cornerstone of the PKIs, needed to establish the trust relationship mentioned above. Hubject offers some more information on their website.
I don’t want to get into too much detail of what a CA does and how this trust relationship is exactly established because that would be a topic big enough for an article of its own. However, if you like, you can get a sneak peek into the ISO 15118 Manual which provides a free extract from each chapter. Chapter 4 on the "Certificate Concept" and chapter 5 on "Certificate Provisioning" teaches you all you need to know to understand the PKI concept in ISO 15118.

Hubject has been closely collaborating with Allego, Audi, BMW, Smatrics, and its subcontractors to clearly define an interface specification with all the messages and parameters needed to conform to the VDE_AR_E_2802-100-1 regulation, thereby using RESTful web services. This document will be published at some point in time during the dissemination process of the Ultra-E project to ensure interoperability and to help other market players that want to implement this promising communication standard.

As the VDE regulation is a document originated by a German organisation, it is not sure yet how the international acceptance will evolve over time. I hope that all interested parties will take a close look at this specification (I will post an update here as soon as it is available in English) and help to improve it over time instead of trying to reinvent the wheel. 

User group for implementation-specific issues

The questions and discussions that arise during the implementation of the VDE regulation are valuable feedback that will in turn influence the next version of this standard. Until then, a forum has been put into place, similar to the ISO 15118 User Group, to exchange and discuss questions and answers regarding the implementation of this specification.

The goal is to form and document a common understanding of implementation details and thereby ensure that different implementations behave compatibly.

ISO 15118
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

An e-book for beginners and experts alike. Reduces the steep learning curve of ISO 15118 by providing a comprehensive and easy-to-understand access to the Vehicle-to-Grid communication protocol. Written by our founder, one of the few co-authors of ISO 15118, this e-book has fast become standard literature in the industry.

Single User


All the knowledge you need to become an ISO 15118 expert


  • Saves you many days of tiresome trial and error
  • Helps you to really understand ISO 15118
  • Free updates delivered to your inbox
Buy now
Multiple users


Are you interested in copies for your colleagues or students? We offer company-wide licenses as well as licenses for academic libraries.


  • Train your team on this future-proof technology
  • Provide access to students of e-mobility tech
  • Ensure updates for each employee / student
  • Unlimited number of copies included in purchase
Request now
Switch Ev | ISO

Want to try before you buy?

Get an extract from each chapter to see the quality and in-depth information you’ll get in the full e-book. The ISO 15118 Manual definitely helps you grow your expertise and positioning in the e-mobility market.

Provide your name and email address to get it delivered to your inbox.

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

Join a group of experts in the know

Since we have published our ISO 15118 Manual it has been purchased by the biggest names in our industry and has become standard literature.

as well as Daimler, Porsche, Shell, Tritium, and many more...

As we were intensively implementing and testing
ISO 15118, we noticed there was a lack of overview of Plug & Charge and the whole supply chain amongst
our stakeholders.

Our training with Marc helped us achieve a much better understanding of the whole ecosystem. It led to constructive discussions on the requirements and concept of ISO 15118 in general.

Angelika Neuleitner,

charging system Specialist at Ionity

Working with recognized standards is the right way forward for the integration of electric vehicles into the grid, and we value Switch’s strong experience with the ISO 15118 standard.

We were able to leverage Marc’s insights to corner some of the keys issues pertinent to V2G in the published standard that needed to be addressed.

Hamza Lemsaddek,

Director embedded solutions at Nuvve Corporation

Attending Switch’s intensive two day training with the team gave us a deep dive into ISO 15118 and the different use cases.

We were able to validate our design with regards to the ecosystem and beyond. We now have a head start for the development of our next generation chargers and are able to support our customers for the deployment of the equipment all over Europe.

Johan Devos,

business development Manager at ENOvates

Certificate handling in ISO 15118 is a quite complex issue. Marc’s well prepared one-day course on this topic and his deep knowledge helped us to train our team and speed up the development of the ISO 15118 Plug & Charge
charging controller.

Johannes Bergmann,

eMobility Charging Systems DEVELOPER at SIEMENS AG

When I was working with students on ISO 15118 projects, Marc's courses tremendously helped in getting students to understand the standard quickly and dive into coding without hesitation. Marc's crystal-clear explanations with eye-catching graphics will make you an EV charging expert in one week.

Minho Shin,

Professor at Myongji University

In two exciting training days, Marc quickly and effectively explained ISO15118 communication to our experienced development team. In addition to the in-depth technical knowledge, the information about the communication standards that are still being established is very valuable. The training will definitely help us to make the implementation more effective.

Reinhard Starzinger,

Project Manager Electric Mobility AT Keba AG


Related reads

Latest News