OCPI - Open Charge Point Interface
Standardising the technology that enables roaming for EV drivers everywhere is a crucial step along the road to truly seamless charging. Here’s how OCPI does exactly that...
When you take your laptop to a coffee shop, you expect that both it and the in-store wifi will have everything they need to make a connection. That’s only made possible because of standardisation in network technology. And the same is true in the world of eMobility.
With EVs, drivers need to be confident that no matter where they go, they can pull up to a charger and top up seamlessly. That’s the aim of the Open Charge Point Interface (OCPI) – a communication protocol designed to standardise the technology that makes roaming, charging and paying possible.
In this guide, we’ll explore what the OCPI does, how it works, and what it means for the future of eMobility.
What is OCPI?
The Open Charge Point Interface (OCPI) is a communication protocol that enables roaming. It links charge point operators (CPOs) with the different back-end technology providers like eMobility service providers (eMSPs) to enable charging that’s network- and EV-agnostic.
In practice, the idea is that if all chargers use the same protocol, drivers can charge anywhere they go without running into incompatibility issues – and that they can enjoy smart features like real-time status and availability of chargers at specific locations.
It also means all the players working behind the scenes are working with the same data, which makes things like billing and security much simpler and more interoperable.
OCPI enables:
- Simple roaming and borderless charging
- Data sharing between eMobility service providers and energy suppliers
- Secure billing and payments
- Hardware agnosticism
OCPI as a standard is being adopted across major markets since governments are seeking ways to make transitioning to EVs simpler for all parties involved. Bodies like the Secretary for State for Transport in the UK, The Corporate Electric Vehicle Alliance in the US, and evRoaming4EU in Europe are working to proliferate OCPI adoption.
The OCPI’s makers – the EVRoaming Foundation – describe OCPI’s aims as follows:
- Accelerate the market for EV drivers
A mature EV market needs a single communication infrastructure where all market players in the EV and energy sectors are connected. New, integrated and profitable business models can be developed that provide flexibility and assure continuity of supply.
- Improve mobility services
EV-drivers may expect to have an optimal user experience, regardless of borders, operators or equipment. Prices, tariffs, locations, availability and a single invoice should be available in real-time in a transparent way.
OCPI vs OCPP
OCPP (Open Charge Point Protocol) is a confusingly similar term, but it’s actually a very different beast from OCPI:
- OCPP: Handles communications between the charge point and the charge management system, in order to monitor and control charging sessions
- OCPI: Builds a bridge between the charge management system and other, external software systems like roaming platforms, payment platforms and eMobility Service Providers.
The core difference between the terms, then, is that while OCCP deals with communication between charging hardware and the backend, OCPI connects the charging network operators and the charging service providers.
And it’s these interoperable, connective abilities that make OCCP and OCPI really important to any business wanting to offer seamless charging.
How does OCPI work?
Cross-company standardisation like OCPI works via Application Programming Interface (API) technology. An API is effectively a way to share data access between two parties in a way that both can use and understand – and in this instance that means exchanging information on things like pricing tariffs, charging tokens, EV ID, location and charging sessions.
There are two key parts to this:
Standardised communications
APIs make it possible for standardised data exchange between key players, including CPOs, energy suppliers and eMobility service providers. That data is sent in secure, interoperable packages that every party can use.
Roaming agreements
This technology relies on agreements between each eMobility service provider, acting here as charging networks. These networks need to work together to establish a secure framework for billing and authorisation. It’s these agreements that allow drivers to charge and pay at any charging station, rather than having to stick to ones operated by their network provider.
OCPI in action
Here’s what happens behind the scenes when an EV driver uses an OCPI-compliant charging station:
- OCPI facilitates the exchange of charging station location data between Charge Point Operators and eMobility Service Providers and provides the driver with up-to-date availability information in their driver app.
- When the driver initiates authentication, the CPO then sends a request to the eMSP via OCPI to verify their credentials. The eMSP checks the driver's account status and sends an authorization response back to the CPO through OCPI.
- OCPI then transmits session start data, including unique identifiers for the session, driver, and charging point. This data is shared continuously throughout the charging session, allowing for live information like energy consumed and elapsed time.
- When charging ends, OCPI transmits final session data, including the total energy usage and duration. That allows CPOs to share pricing and billing information with eMSPs.
- If the driver is using a different eMSP than the CPO's default, OCPI then manages the data exchange for cross-network billing and reconciliation.
Advantages of OCPI in EV charging
The Open Charge Point Interface is a win-win for drivers and the businesses that make charging possible. Sharing data to make charging provisions more unilaterally available means the former gets more choice when it comes to charging, and the latter can welcome a much larger range of customers:
OCPI advantages for EV drivers:
Increased charging accessibility
OCPI makes it so that drivers can take advantage of chargers not native to their usual provider’s network. That means they have many more options when driving away from home.
Enhanced user experience
These open, agnostic roaming capabilities make the process of charging an EV much simpler, because it means that drivers don’t have to have multiple apps and accounts with various charging providers.
Simplified billing
Likewise, OCPI transfers payment and billing information between eMobility Service Providers, making payments for out-of-network charging a simple, one-step process that doesn’t ask anything new of the driver.
OCPI advantages for businesses offering EV charging (CPOs):
Expanded customer reach
With open, simple charging that can transcend networks via roaming agreements, OCPI makes it easier for drivers to find and use your chargers. That means more customers and more robust revenue streams.
Enhanced brand visibility
OCPI makes it so that your chargers will show up on the results page of charging station-finding apps, which means more drivers will be aware of your business and brand.
Potential for revenue sharing
Roaming agreements make it possible for CPOs to accept drivers from other network providers, and receive income in the way of revenue sharing from those networks as per their roaming agreements.
OCPI versions and future developments
OCPI is an ever-evolving standard. As EV adoption proliferates and charging technology changes, subsequent OCPI versions will roll out with new features. And in fact, we’ve already seen this play out:
OCPI 2.1.1: This is the most widely adopted version of the standard, which focuses on core roaming functionalities. This included setting out communications protocols for roaming, tariffs, billing, Real-time charge point information, session information and more.
OCPI 2.2.1: Introduced improvements in data exchange capabilities and support for additional features like smart charging integration. Here are two key areas where the 2.2 version of OCPI has made major strides:
- Hub communication support
This essentially lets CPOs understand which third-party service providers are currently online and actively working with their chargers
- Smart charging
Smart charging means rule-based charging that can help ease strain on the energy grid using features like dynamic load balancing.
And as for the future? Well, OCPI 3.0 is already in the works and is currently available in ‘draft’ version, and is set to bring with it a bunch of game-changing new features:
- Driver communication
OCPI 3.0 brings with it the ability to display messages aimed at the driver directly on the charging terminal display. This might be billing information or an explanation of any possible issue with charging or payments.
- Plug & Charge
Plug & Charge uses secure digital certificates to identify a driver’s EV and begin a charge that automatically links the session to that driver’s account. The upshot of this is that drivers don’t need an app or an RFID card to begin a session – making EV charging feel more like filling up a traditional, petrol-fuelled car.
- Greater security
The same technology that allows for Plug & Charge carries with it a bunch of innate security enhancements. EVs are able to be identified and linked to a charging session via secure, encrypted digital certificates – this makes communication between providers even more seamless, without needing drivers to share any personal details.
There’s a great list of all the upcoming features that OCPI 3.0 will make possible here.
Spirii and OCPI
Spirii believes that roaming is at the heart of seamless EV adoption and ownership – and that CPOs need to be able to offer fully interoperable charging that stays up to date with changing standards and technology.
That’s why we have roaming agreements with market-leading service providers, as well as a hardware certification program that means we only offer charging stations that are fully OCPI (and OCPP) compliant.
If you’re looking to offer smarter, simpler charging to EV drivers, get in touch using the button below and we’ll help guide you to your dream charging solution.