How does the money actually get from me to the charging station operator? (feat. smart charge@street)

Thanks to my supporters:

Although I come from the charging infrastructure industry myself, I am much more involved in construction and the hardware side. Accordingly, it was great that Andreas Memmer from Pfalzwerke, a local infrastructure provider in Germany, took the time to help me correctly classify all the terms.



First the terminology


As in every industry, there are of course a few terminologies that you can't get around. I would also like to mention the associated abbreviations, but I will use terms that make it easier to follow the topic:

  • Charge point operators are called "CPO". Their task is to operate the charging station itself. They own the charging station, where you finally plug in the charging cable and hold the card in front of it to charge. They bill the charging card providers and are responsible for the operation and service of the charging station. Of course, they also buy the electricity, which is then charged into the cars.
  • Charging card providers are called "EMP" (-> E-Mobility provider). Their job is to issue charging cards and have them work at as many charging stations as possible. They also bill the customer for the electricity and have to negotiate with the charging station operators. Strictly speaking, the charging card provider naturally buys the service of being able to charge at the charging station from the charging station operator and resells this service to the customer.


Of course, a provider can be a combination of both or just cover one of the two services. For example, the Pfalzwerke offers charging stations and charging cards with their e-mobile tariff, smart's charging card is only a charging card and as the operator of my own charging station in the village I am exclusively a charging station operator.


Another big term here is the so-called backend. This is practically the server in the background, which is in direct connection with each charging station and the other operators. Large providers have programmed and operat something like this themselves. For example, Siemens and ABB, do so. Smaller providers buy server space from larger providers. Greenflux, for example, but there are also many others. My own public charging station also uses one of these.

The type of data transmission between charging station and backend runs via standardized protocols. The most common is OCPP, although some operators are currently adding OCPI to it:


  • OCPP (Open Charge Point Protocol) is the most widely used protocol in the industry and since version 2.0 it also supports ISO 15118, which supports, among other things, the most widely known Plug & Charge prototcol. It is a universal protocol that serves as an interface between all different charging stations and backends.
  • OCPI (Open Charge Point Interface) offers both a connection via a roaming platform and a direct connection to other providers. It also allows dynamic prices.
  • OICP (Open Intercharge Protocol) is similar to OCPI but only connection via roaming platform are supported. It is a proprietary protocol of Hubject, one of the largest operators when it comes to connecting to many small operators. There is more information about Hubject below.


The ISO 15118 is often used in a sentence with Plug & Charge, with this method the car is automatically recognized when you plug it in. The system then automatically searches for my charging card provider and then starts charging. I don't have to hold a charge card up to the chargingstation. This is currently the biggest advantage of this standard for end customers.

But the standard can do much more. It defines the communication protocol between the car and the charging station. It is also possible, for example, to charge bidirectionally if the vehicle and the charging station support this. Or tell a dynamic load management system how much electricity the car still needs and when it needs to be full so that peak loads can be avoided.



The way of your money


With the theory out of the way, we can finally look at a simple graph. In most cases, the path of the money is as follows:


Weg des Geldes Infografik EN


You hold the charging card against the Pfalzwerke charging station and it recognises the charging card via RFID. It then transmits this data to the backend of Pfalzwerke via OCPP. This now has the task of finding out whether the Pfalzwerke themselves know this card, i.e. whether it is their own customer. If so, the issue is quickly resolved and the charging process begins.

But mostly it is so-called roaming. As with cell phones, they then have to see who operates this card. Smaller providers like to use Hubject for roaming. For example, at my own charging station, practically all charging processes go through Hubject. They then mediates from the Pfalzwerke to the provider of my smart charging card. Hubject is a provider, which hast with practically every provider a contract. No matter how small they are.

Of course, large providers in particular are happy to negotiate directly with the providers and can thus save themselves a middleman like Hubject. Then it goes directly from the Pfalzwerke backend to the smart backend.



Contracts between backends, who gets the blocking fee?


I use the smart card to pay the rate that smart charges me. However, that does not determine what smart gives the Pfalzwerke for the charging process. The kWh price, a starting fee or a blocking fee is negotiated from backend provider to backend provider. For example, if someone uses their Pfalzwerke card to charge at my own charging station, they might pay a blocking fee to Pfalzwerke, but since my station and its backend don't charge a blocking fee, I don't get a blocking fee.

But it can also be the other way around. The Pfalzwerke charging station charges a blocking fee from the smart card, even if the card itself does not charge the customer. Then smart has to put it on top. Of course, this is where the big game of negotiations between providers begins. This task can occupy entire offices, so smaller providers in particular choose to use Hubject as middleman. Then they only have to negotiate with Hubject and also have a fixed price.


The basic path of money is documented quite quickly and simply, and understanding it to this extent is completely sufficient. Especially as an end customer, you already know a lot more than you need to now.

In the industry itself, of course, it quickly becomes much more entangled. Blocking fee is just an example here. Different providers have different price concepts. Some even dynamically according to the current electricity price or for fixed quotas. In addition, there are also different ways, whether payment is made with RFID or the EC card. The latter also reaches the backend of the station and is forwarded from there.


All these contracts and dynamics in the background have an advantage for the end customer:

Thanks to clever adjustments and dynamics, the charging card provider can offer a tariff that is as easy to understand as possible and the customer has it as transparent as possible. Practically what we also know from the electricity tariff at home.

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