Understanding OCPI. Fundamentals of EV Charging Industry Start Guide

“OCPI (Open Charge Point Interface) serves as the conduit for sharing charge point information across diverse networks. This standardises a RESTful service between servers, a creation of the EV Roaming Foundation, now maintained as a public asset from its members.

HLD of OCPI and network sharing

Things to keep in mind

Simple Explanation Of OCPI OCPI is a protocol for sharing charging stations. OCPI development is easy yet complicated as go deeper.

Versions of OCPI there are 2 commonly used versions in OCPI which are 2.0 and 2.2.1 and 2.2.1 is the most latest one. OCPI servers may have multiple versions at a time and the connecting party can choose one. Im attaching a json response of my OCPI Versions here

{
    "status_code": 1000,
    "status_message": "Success",
    "timestamp": "2023-11-24T15:44:19.450119",
    "data": [
        {
            "version": "2.2",
            "url": "https://tis-uat.console.chargemod.com/ocpi/2.2/"
        },
        {
            "version": "2.2.1",
            "url": "https://tis-uat.console.chargemod.com/ocpi/2.2.1/"
        }
    ]
}

CPO (Charge Point Operator) The Charge Point Owner (CPO) is identified as the individual or organization responsible for the ownership and operation of a given charging station. It is pertinent to note that ownership of the physical infrastructure, namely the charging station, does not inherently confer the role of CPO. In instances where the entity installing the charging station lacks the requisite compatible software or any operational software, the designation of CPO may shift to the party possessing and maintaining the necessary software infrastructure. This distinction is crucial in understanding that the CPO is effectively the entity whose server the charging station is connected to, emphasising the significance of software compatibility and operational control in determining the true proprietorship of the charging infrastructure.

EMSP (E-Mobility Service Provider) The e-Mobility Service Provider (EMSP) assumes the role of the entity or organisation responsible for delivering comprehensive electric vehicle charging services. Similar to the Charge Point Owner (CPO), the EMSP is distinguished by its operational involvement, extending beyond the physical charging infrastructure. It is imperative to recognize that not all entities deploying charging stations necessarily fulfill the requirements of an EMSP, especially in cases where there is a lack of compatible software or operational capabilities. In scenarios where the party installing the charging infrastructure lacks the requisite software infrastructure, the designation of EMSP may transfer to the entity possessing and maintaining the necessary software. This nuanced understanding underscores the pivotal role of software compatibility and operational proficiency in determining the authentic stewardship of the electric vehicle charging services. In essence, the EMSP is identified by its connection to the software infrastructure supporting the charging network, elucidating the vital role of comprehensive service provision in the realm of electric mobility. There are other roles in OCPI such as HUB etc. All such roles are in the basis of CPO/EMSP. Understanding this falls on the basics.

How It Works?

OCPI is a set of RESTFUL APIs that are predefined. There are options for you to create your on custom API inside OCPI on top of what is predefined. Lets start with modules. What is modules? modules are the functional features of OCPI. One of the examples of modules are “Locations”. As the name suggests, it is a module which handles the location(Where the data of charging station details such as address, id, availability, etc are). Module Identifiers Module identifiers is the is the part where we list the API endpoints. There are 2 kinds of endpoints (roles of identifier) will be available for each modules. They are SENDER and RECEIVER. As the name suggests, it is the role of the identifier where data is being Sent or Being Recieved. eg;- for locations module identifier SENDER role URL is used for getting all locations details. i have a json response of this module identifiers list commonly known as endpoints in OCPI.

{
    "status_code": 1000,
    "status_message": "CMD Entpoints for version 2.2.1",
    "timestamp": "2023-11-24T15:33:19.535388",
    "data": {
        "version": "2.2.1",
        "endpoints": [
            {
                "identifier": "credentials",
                "role": "RECEIVER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/2.2.1/credentials"
            },
            {
                "identifier": "commands",
                "role": "RECEIVER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/cpo/2.2.1/commands/"
            },
            {
                "identifier": "locations",
                "role": "SENDER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/cpo/2.2.1/locations"
            },
            {
                "identifier": "locations",
                "role": "RECEIVER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/emsp/2.2.1/locations"
            },
            {
                "identifier": "sessions",
                "role": "SENDER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/cpo/2.2.1/sessions"
            },
            {
                "identifier": "sessions",
                "role": "RECEIVER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/emsp/2.2.1/sessions"
            },
            {
                "identifier": "tariffs",
                "role": "SENDER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/cpo/2.2.1/tariffs"
            },
            {
                "identifier": "tariffs",
                "role": "RECEIVER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/emsp/2.2.1/tariffs"
            },
            {
                "identifier": "tokens",
                "role": "SENDER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/emsp/2.2.1/tokens"
            },
            {
                "identifier": "tokens",
                "role": "RECEIVER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/cpo/2.2.1/tokens"
            },
            {
                "identifier": "cdrs",
                "role": "SENDER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/cpo/2.2.1/cdrs"
            },
            {
                "identifier": "cdrs",
                "role": "RECEIVER",
                "url": "https://tis-uat.console.chargemod.com/ocpi/emsp/2.2.1/cdrs"
            }
        ]
    }
}

from the above set of endpoints, other OCPI parties may utilise all limited controls of a chargepoint network.

What is a HUB?

What actually happens when you do not offer any service like E-mobility and do not own any charging stations ( CPO )? you can actually make another service for connecting both parties. for instance EMSP do have mobile application service and CPO do have chargepoints at their disposal and you may connect both parties via you by acting as a HUB which is collections of acting as CPO and and EMSP In the meanwhile you may act as DSO where OCSP Comes into play where you may control smart profile for this