OPCP (Open Plug & Charge Protocol) is an open protocol, published by Hubject in February 2022, that standardizes communication between backend services supporting ISO 15118 Plug & Charge. It defines interfaces for certificate pools, certificate provisioning services and other functions needed to manage digital certificates across different Plug & Charge systems, connecting vehicle manufacturers, charge point operators (CPOs), e-Mobility Service Providers (eMSPs) and PKI operators.
How does OPCP support Plug & Charge?
Plug & Charge lets EV drivers start charging automatically by connecting their vehicle to a compatible charger, without an app or RFID card. Several protocols support this process, each handling a different part of the communication:
| Protocol | Connection | Role |
|---|---|---|
| ISO 15118 | Vehicle to charger | Secure communication and certificate-based authentication |
| OCPP | Charger to management platform | Certificate management and charging authorization in OCPP 2.0.1 and 2.1, where the relevant ISO 15118 functions are implemented; OCPP 1.6 requires extensions |
| OPCP | Backend services | Standardized access to the root, provisioning and contract certificate pools, the certificate provisioning service and other Plug & Charge functions |
How does OPCP work?
Plug & Charge relies on a public key infrastructure (PKI) to issue, manage and verify digital certificates used for secure authentication. A typical Plug & Charge process runs in four steps:
- Vehicle provisioning: The vehicle manufacturer installs a provisioning certificate in the vehicle and publishes the corresponding certificate to a provisioning certificate pool, where authorized service providers can retrieve it.
- Contract certificate creation: When a driver registers for Plug & Charge, the eMSP arranges for a contract certificate to be issued. A certificate provisioning service creates or signs the associated contract data, which can then be stored in a contract certificate pool for installation in the vehicle.
- Certificate installation: The contract certificate is installed in the vehicle through a supported process, which may involve the charger or the vehicle manufacturer’s backend.
- Automatic authentication: When the vehicle connects to a compatible charger, it presents its contract certificate to authenticate the session, provided the charger’s operator trusts the same root certificates and the required authorization arrangements are in place.
What’s the difference between OPCP and OPNC?
OPCP was developed by Hubject. OPNC (Open Plug & Charge Network Communication), coordinated by CharIN, builds on OPCP to connect Plug & Charge ecosystems that use different PKIs.
Gireve publishes a third protocol, PNCP, for connecting to its own Plug & Charge services.
Why does OPCP matter for charge point operators and eMSPs?
For CPOs and eMSPs, OPCP offers one documented way to connect with Plug & Charge certificate services.
A CPO needs compatible charging equipment, a charge point management system (CPMS) that supports Plug & Charge, and access to certificate and authentication services. An eMSP needs a way to arrange and manage contract certificates for its customers, typically through a certificate provisioning service. These services can be provided by a PKI operator such as Hubject, rather than built in-house.
Interoperability also depends on compatible hardware, trusted certificates, valid contracts and supported integrations; OPCP standardizes only the backend exchange.
How AMPECO supports Plug & Charge
AMPECO is a certified Hubject Plug&Charge backend provider. CPOs and eMSPs on AMPECO’s EV charging management platform can offer certificate-based authentication through Hubject’s Plug & Charge services, as described on AMPECO’s Hubject integration page. On the charger side, the platform implements the OCPP 2.0.1 ISO 15118 functions, which carry certificate installation and updates.
AMPECO’s guide to ISO 15118 for CPOs and eMSPs explains the PKI and how Plug & Charge certificates pass through OCPP.
Related terms
Frequently asked questions
What is the difference between OPCP and OCPP?
OCPP manages communication between EV chargers and their charging management platform, including Plug & Charge-related functions. OPCP standardizes communication between the backend services that issue, store and exchange Plug & Charge certificates. The two acronyms use the same four letters, so OPCP is often mistaken for a typo of OCPP.
Does Plug & Charge require OPCP?
No. Plug & Charge needs an ISO 15118-capable vehicle and charger, a contract certificate from the driver’s eMSP and a PKI that both sides trust. Backend providers can exchange certificates through OPCP, CharIN’s OPNC, Gireve’s PNCP or their own interfaces.
Is OPCP the same as OPNC?
No. OPCP was published by Hubject in 2022. OPNC is coordinated by CharIN and extends OPCP so that certificate services run by different PKI operators can work together, which matters where a market has more than one Plug & Charge PKI.
Is OPCP open source?
Yes. Hubject publishes the OPCP specification on GitHub under a Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license. Organizations can read it and build their own compatible implementations; the repository holds the specification only, with no ready-made software.
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