Decentralizing the charging business for the eMobility Industry (part III)

Hector Garcia
May 15, 2018 · 8 min read

The future of EV (Electric Vehicle) mobility strives for a seamless integration of diverse sovereign individuals, entities and machines, together participating in a system powered by green energy flowing back and forth between batteries and points of charge distributed everywhere. A world of manned and unmanned driving vehicles that make use of a decentralized charging infrastructure, where the transfer of value (electricity for money or tokens) is trusted, automated, free of local constraints or barriers such as pre-contracts with suppliers, payment methods supported, accepted currencies, or security risks like fraud or theft.

This post is the third (and last) part of a series of three articles. In the first one I described what is happening today, depicting a business dominated by MSPs (Mobility Service Provider) and CPOs (Charge Point Operator) that bring EV drivers to a post-payment scenario. In the second piece I propose an architecture that introduces a Blockchain (i.e. Ethereum) based EV Network for the governance of transactions, along with some EV components that, placed in the right manner, can transition our current system to a pre-payment scenario while partly removing single points of failure and inefficiencies.

This last blog post is focused on how we can dream of pushing even forward our tech stack into a landscape of autonomous smart agents that leverage the properties of Distributed Ledger Technologies (DLT), redistributing how we operate our network by combining technologies that are becoming progressively ready in the Blockchain scene.

One step further

The first architecture proposal in my previous post, that used EV software components to help transitioning the charging infrastructure to a decentralized system, was thought to be as least invasive as possible for the stakeholders to adapt to. On one hand, CPOs only needed to talk to our Core Client as if it’s just another MSP. MSPs, on the other hand, needed to integrate the business logic to talk to the EV Network as if it was just another CPO.

But DLTs require a whole transformation that has to be deeply understood and embraced at all levels, including of course the technical aspects. Our next steps towards decentralization will mean putting more control and trust in two main places:

  • Our EV Network: especially important for the charging infrastructure management, because we want to minimize unilateral control on the CPO side by becoming and authoritative source and exposing all operations and their related outcomes directly to the participants, who can then audit and rely on the results of every charging session.
  • The CP (Charging Point) and the EV: as the actual agents responsible for performing the exchange of value (electricity for tokens), they are in the best position to enforce methodologies to check the integrity and reliability of the transfer.

This level of decentralization on IoT (Internet of Things) devices and Blockchain is going to be even more important when we want to interconnect other business models into our own one. For instance, car parking systems that will allow us to incorporate a highly demanded feature (yet still not deployed) for the charging business such as reservation of charging spots, so drivers can make sure beforehand that the car space and the socket will be free when they arrive to charge.

Architecture proposal

Figure 3

By following the diagram in Figure 3 (see figure 1 and 2 in the previous articles to compare) from bottom to top, we can see how the charging session journey has changed and evolved:

  • The EV receives the station ID directly from the CP via the communication rules defined by the Plug&Charge protocol (as part of the ISO 15118 standard). Note that the drivers may not need to interact at all with the ICE (In-Car Entertainment) if they have a pre-defined profile that provides the charging preferences and accepts the conditions needed to start the charging session automatically. This would be, for instance, the case of self-driving cars.
  • The EV Wallet gets the station ID and any other necessary information from the VCU (Vehicle Control Unit) and files a new charging session request to the EV Network. The Core Client that is stored inside the charging point picks up the request.
  • The tokens from both parties are stored in an escrow account, as part of the micro-transactions process (see further in this article) until the transaction (TX) is completed.
  • The transfer of energy is going to be executed in an off-chain level and may comprise different transactions. Orchestrated by the CSMS (Charging Station Management System) business logic in the EV Network smart contracts, the two IoT devices complete the charging session.
  • The total amount of tokens spent have already been sent to the owner of the station (e.g. CPO wallet) during the process, hence there is no need to calculate final settlements or send back token remainders to the driver.
  • The CPO can create its official invoice, which the driver receives as a support document for the transaction.

EV Network as Authoritative CSMS

In our previous scenario from the second part of this article series, the CSMS is in control of handling the charging infrastructure provisioned in our EV Network, and we need to rely on this element as the authoritative place to ask when something happens. Our whole fleet of charge points depends also on this central controller to be up and running all the time, functioning properly.

But what if we could move all the CSMS functionality to the smart contracts in our EV Network? We could then remove inefficiencies in all the unnecessary communications hops between CSMS, Core Client and EV Network. All transactions would now be executed by the EVM (Ethereum Virtual Machine), a system that is tamper-proof, and that now would put the information about the charging session in direct contact with the value (tokens). We could thus implement the OCPP (Open Charge Point Protocol) features in smart contracts.

With this bold approach, now have a reliable (albeit very slow) machine where we can tie better the charging operations to the associated agreement between the two participants in the exchange of electricity from CP to EV. I am aware that this scenario may be, as of today, too optimistic because of the current technology endeavors that Ethereum is facing, like scalability or speed of transaction processing. However, I also feel confident that we can strive for this by combining different techniques and approaches. In the next sections I try to explain some of them.

IoT challenges

Our future machine-to-machine economies will demand smarter devices, capable of operating in an unmanaged way, making decisions based on AI, deep learning, and other less sophisticated algorithms. If we want to decentralize our system, we need to put more control on the IoT side and trust on the devices dealing with charging and discharging our batteries when V2G (Vehicle 2 Grid) is available mainstream.

The Ethereum industry is struggling with ways to be able to run “light” clients in embedded devices, which are very limited in resources such as processing power, storage or connectivity. The Light Ethereum Subprotocol (LES) implemented in both Geth and Parity (the two most popular Ethereum clients today) allows us to connect directly the charging stations and the EVs to the EV Network. Both of them would only need then to run a stripped down version of our Core Client service to implement the business logic needed to act as a bridge between the EV Network (via Ethereum light client) and the CP (via OCPP).

Empowering stations and EVs means that we can insert hardware and software solutions to leverage the performance of communication between them, improve the security through measurements such as regulations for compliant devices, like smart metering (e.g. in Germany it’s called “Eichrecht”, see page 4 of this resource here) on CPs or access restrictions on a VCU while also enabling them to perform cryptographic signing of transactions or other operations. This last functionality is subject to security issues, and the industry tries to solve those with different ideas. For instance, by incorporating secure processors that implement the critical operations to ensure the correct behaviour of the device and protect secret data. One example is the SEP (Secure Enclave Processor) on the iPhone.

Micro transactions

I think we cannot forget that, while we want to use the properties and benefits that Blockchain brings and we put dependencies and trust in on-chain decentralized solutions, we are in the end dealing with a transaction that happens off-chain between a CP and an EV. The agreement for the charging session is settled initially by the driver trusting that the amount of electricity is going to be delivered, and the locking of tokens in an escrow account in the initial architecture design expressed that (again, see figure 2 in the previous article). When the CDR (Charge Detail Record) is presented as the description of a concluded charging session, the final amount of tokens is calculated and transferred from the escrow to the owner of the charging station.

In this situation the MSP side must still expect that the CPO side will fulfill its part in the deal. But what if the driver or MSP discovers, for instance, that the energy supplied does not match with what they expected? With our new architecture described above using micro-transactions, as the control is put directly to our both parties participating in the transfer of electricity, we can leverage how we supervise that the contract is being delivered as promised and how the tokens flow from one wallet to another.

Bringing transactions to a micro level is a popular concept for the energy sector. The idea is to open an off-chain channel between the CP and the EV (in particular, the VCU) for a charging session, where both parties deposit tokens and perform bidirectional transfers, which in this case corresponds to “chunks” of electricity from the charge point to the car. Applied to our scenario, by using this approach the VCU can then monitor or “verify” every micro-transaction, e.g. by checking the battery status. By supervising transactions in a detailed way, we can reduce the window of opportunity to disagreements, reduce fraud or unnecessary logic, and implement algorithms to enable the so-called smart charging.

This technology is complex and is still under heavy development. In Ethereum the leading project is called Raiden, and there is already a framework called µRaiden that we can experiment with to provide pay-per-use solutions on top of IoT markets such as the one I propose here.


I tackled an ambitious goal with these three posts and I certainly only scratched the surface. I am however convinced that the revolution that is coming, which I mentioned in the very beginning of the first post, is really up to us to make it happen. I am therefore so happy to be part of the early adopters, contributing to make this grow and mature. If you have ideas, propositions or anything you would want to share with me, do not hesitate to contact me here at Medium, on my twitter or my LinkedIn. Thanks for reading!


Seamless, Smart & Green Charging — Share&Charge is curating…


Seamless, Smart & Green Charging — Share&Charge is curating the Open Charging Network to enable the highest level of interoperability and transparency in electric mobility.

Hector Garcia

Written by

Serial entrepreneur, Python hacker, Crypto enthusiast. Head of Innovation at, co-founder of I am a catalan.


Seamless, Smart & Green Charging — Share&Charge is curating the Open Charging Network to enable the highest level of interoperability and transparency in electric mobility.

Medium is an open platform where 170 million readers come to find insightful and dynamic thinking. Here, expert and undiscovered voices alike dive into the heart of any topic and bring new ideas to the surface. Learn more

Follow the writers, publications, and topics that matter to you, and you’ll see them on your homepage and in your inbox. Explore

If you have a story to tell, knowledge to share, or a perspective to offer — welcome home. It’s easy and free to post your thinking on any topic. Write on Medium

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store