What is OCPI? How EV Roaming Boosts Revenue for EV Charging Stations

Introduction: From Isolated Chargers to Interoperable Networks

Traditionally, charging ecosystems have been closed ecosystems, where a given application, RFID card, or subscription service was limited to working with a single operator’s charging stations. This meant a frustrating user experience for drivers, with a proliferation of applications and a lack of roaming between them, and a lack of utilisation and therefore a poor return on investment for charging station owners.

With OCPI, however, charging station operators are now able to offer a new service to their users: roaming, or the ability to charge with one application or subscription service on a competitor’s charging station without having to subscribe to a new service. This is a game-changer, transforming a series of isolated charging stations into a network, and opening up new revenue streams for Charge Point Operators (CPOs) and charging station owners.

In this document, we aim to demystify OCPI, walk you through an end-to-end explanation of EV roaming, and highlight its benefits to charging station owners, with a special focus on the Indian market and Savekar’s WhatsApp-first CMS sitting atop OCPI-ready platforms.

What Is OCPI in Simple Terms?

The Open Charge Point Interface (OCPI) functions as a standardised open protocol that enables different electric vehicle charging systems to connect with each other while enabling users to charge their vehicles at different locations. The OCPI standard provides CPOs with a common vocabulary to share essential details between their systems and eMobility Service Providers, which includes:

• The position and active condition of charging stations.
• The user (token/app) is trying to charge their device, and their current authorisation status.
• The session data contains information about the session start and end times, the total energy consumption, and the different pricing options.
• The billing and settlement process requires Charge Detail Records CDRs as essential documentation.
  

As it is open and flexible, it is now the de facto standard for roaming in Europe and is increasingly cited as best practice in other regions, like India, too. The current popular version is OCPI 2.2.1, including modules for smart charging and more advanced roaming scenarios.

OCPI vs OCPP: Two Layers of Interoperability

OCPI is often mistaken for Open Charge Point Protocol (OCPP), but they actually solve very different problems.

OCPP takes care of the communication between the charging station and its own management system, whereas OCPI takes care of the communication between different networks such as CPOs, eMSPs, and roaming hubs.

Many regulators today mention both in their documents. The Bureau of Energy Efficiency (BEE), a department of the Indian government, mandates the implementation of OCPP 1.6 for publicly funded charging stations. Recently issued guidelines for EV charging in the country mention both OCPI and OCPP for payment and access solutions for a seamless experience.

Here’s a handy checklist for you:

• OCPP: ‘Can my CMS talk to my charger?’
• OCPI: ‘Can my network talk to other networks?’

Both must be capable of generating that seamless experience needed for roaming.

Key Players in an OCPI‑Enabled EV Roaming Ecosystem

OCPI facilitates the standardisation of communication between a number of roles in the EV charging ecosystem.

• Charge Point Operator (CPO):

The CPO owns the charging stations, which are part of their physical charging network.

• eMobility Service Provider (eMSP):

The eMSP provides drivers with access to their applications, cards, and membership programs, which they need for charging.

• Roaming hub:

This is a platform that acts as an intermediary between many eMSPs and CPOs by facilitating a single interface.

• Driver:

The driver uses the app/card provided by a single eMSP to charge from many different networks.

• OCPI supports two models of roaming:

peer-to-peer and hub-based roaming.

This variety is part of the reason why OCPI is the most popular roaming protocol in Europe.

How EV Roaming Works Step by Step

The ability of a driver to charge at a CPO’s station, even if they are a member of another provider’s network, is enabled by EV roaming.

A standard flow of an OCPI-based roaming process:

• Discovery:

A driver uses their eMSP app, which shows available chargers from multiple networks (using location and tariff information from OCPI).

• Initiation:

A driver initiates a charging process by scanning a QR code, inserting an RFID card, or clicking “start charge” within an app.

• Authorisation:

A CPO’s system requests authorisation from an eMSP or a roaming hub via an OCPI protocol to verify a driver’s credentials and contract status.

• Charging session:

Once authorised, a charger begins to provide power, and a CPO and an eMSP simultaneously monitor a charging session’s status, energy consumption, time, and tariffs.

• CDR and settlement:

When a charging session is complete, a CPO sends a Charge Detail Record to an eMSP containing all relevant information to charge a driver and pay a CPO.

What Does OCPI Actually Exchange?

OCPI is a modular protocol. Each module is designed to handle a certain domain of data.

Some of the most common OCPI modules are:

• Locations: Station locations, station connectors, power level, opening hours, and real-time status.
• Tariffs: Pricing schemes, such as per kWh, per minute, idle costs, and roaming markups.
• Tokens: User identification, RFID cards, and application tokens.
• Sessions & CDRs: Real-time session data and final Charge Detail Records for billing.
• Commands: Send remote start/stop and other commands.
• Versions & Credentials: Server capabilities and authentication between OCPI servers.

The OCPI protocol is based on API and utilises HTTPS with high-level security to safeguard user and transaction data.

Why EV Roaming Increases Revenue for Charging Stations

From a CPO’s or site owner’s point of view, OCPI-enabled roaming is not just a technical feature; it is a business growth lever.

1. Higher Utilisation of Existing Chargers

CPOs spend a lot of capital on chargers, civil works, and grid connections. The capital costs are largely fixed costs; hence, higher utilisation improves the business case for each charger.

Roaming increases utilisation by:

• Gaining access to drivers from partner networks who might otherwise not stop at your location.
• Making your location visible in more apps/maps.
• Removing the barrier of sign-up for more drivers to use the charger when they spot your location.

Platforms like AMPECO position roaming as a way to “maximise the revenue potential” of existing stations by leveraging external demand.

2. Access to New Customer Segments

With roaming, your station can serve:

• Out-of-town or cross-border drivers whose primary eMSP is different.
• Fleet operators who have roaming agreements through their own platforms.
• Drivers loyal to a competing OEM or eMSP brand that has roaming relationships.

Without roaming, these customers are essentially locked out of your stations, resulting in lost revenue even if your stations are idle.

3. Improved Driver Experience and Repeat Business

Roaming removes barriers to charging by eliminating the need for multiple memberships and RFID cards. The system allows one payment method to function throughout every network. The improved customer experience leads to increased customer purchasing behaviour:

• Stop to charge when they see your station.
• Return to locations where they have enjoyed a seamless roaming experience.

As several roaming providers point out, every step in the charging process represents an opportunity for a consumer to avoid a charging session altogether. Removing those barriers, such as through roaming, is one of the most powerful ways to increase consumer usage.

4. Cross-Border and Inter-City Revenue Opportunities

For CPOs in locations along state borders, highways, or popular tourist routes, roaming enables your charging points to serve international and inter-city travellers without requiring any development of apps or payment schemes.

In regions like Europe, roaming via the OCPI protocol plays a vital role in facilitating long-distance travel, where users can “just plug in and go” without worrying about the operator of the charging point. This trend may soon emerge in India’s highway and tourism-based EV routes.

5. Data for Smarter Pricing and Network Planning

Roaming provides you with more detailed data about the usage of your charging points. This helps you:

• You should adjust your pricing approach according to the different usage patterns, which include peak and off-peak times as well as roaming and non-roaming customer behaviour.
• Plan additional charger locations based on existing usage patterns.
• Offer tiered pricing schemes based on roaming vs. non-roaming customers.

Advanced roaming platforms highlight “analytics” as a key benefit. This includes increased transparency in terms of usage, revenues, etc.

EV Roaming and OCPI in the Indian Context

Currently, the Indian market has a growing base of public EV charging infrastructure with more than 12,000 public charging stations expected to be in place by 2024-2025.

The major trends that are applicable to the Indian market for the implementation of OCPI and EV roaming are as follows:

• OCPP mandates: Publicly funded stations need to be equipped with OCPP 1.6, thereby providing a base for open chargers that can be connected using any CMS.
• Policy emphasis on interoperability: The Indian government has developed charging infrastructure guidelines that mandate the use of OCPP and OCPI as open protocols for interoperability.
• Rise of aggregator and roaming platforms: Indian solution providers are now starting to develop the roaming layer that enables a driver to use any network through a single interface.

For Indian CPOs and site hosts (hotels, malls, offices, societies), being OCPI-ready enables them to connect to these emerging roaming platforms.

How Savekar Fits Into an OCPI‑Ready, Roaming‑Driven Future

Savekar’s goal is to make EV charging commercially viable and easy to operate for property owners in India through their WhatsApp + UPI first CMS.

Key strengths of Savekar’s approach:

• App-less charging experience: Users scan a QR code and start charging. They also receive updates on sessions directly in WhatsApp. They can make payments through any UPI app.
• Direct UPI Payments and Revenue Retention: The site owners retain 100 per cent revenue from charging sessions and are also in control of their own tariff plans.
• Real-time Analytics: The site owners also benefit from real-time analytics as the sessions and revenue are available in the cloud-based dashboard.
• Partner APIs: The charging infrastructure can be integrated through APIs as well. The APIs are RESTful.

Regarding roaming, an important aspect, Savekar has also developed an internal simulator for the OCPI 2.2.1 EMSP to validate the correctness of the CPO implementation. This demonstrates that the backend of the platform is being designed to be OCPI-compliant.

For CPOs and enterprise customers, this means:

• Savekar-enabled chargers can be tested against OCPI flows.
• Future roaming integrations with eMSPs/hubs can be based on a protocol-aware foundation.
• WhatsApp + UPI can provide a local, India-friendly UX on top of globally recognised roaming standards.

Savekar provides site hosts with a profitable short-term business solution that enables them to achieve future operational compatibility through its dual Indian payment system (UPI, WhatsApp) and international electric vehicle (EV) roaming standard (OCPI) capabilities.

Practical Roadmap: Making Your Charging Network OCPI‑Ready

For a CPO or site owner with many sites, the process to support roaming is a process rather than an event.

Step 1: OCPP Compliant and CMS Connected Hardware

• Install OCPP-compliant hardware to communicate with a modern CMS.
• Select a modern CMS that exposes APIs and provides remote control, metering, and error detection.

For example, Savekar provides a CMS with remote monitoring, dynamic load management, and direct UPI billing through WhatsApp, which can be placed on top of OCPP-compliant hardware.

Step 2: Select a CMS or Platform with Support for OCPI

• Your CMS or platform must maintain compatibility with OCPI 2.1 and OCPI 2.2 standards, or it should have an existing roadmap along with testing tools to support OCPI 2.2.1.
• The system needs to verify its ability to support all essential OCPI functional modules, which include Locations, Tariffs, Tokens, Sessions, CDRs and Commands.

Platforms such as AMPECO and others proudly promote their support for OCPI as an essential component for roaming.

Step 3: Decide on Roaming Strategy: P2P vs Hub

• Peer-to-peer: Directly connect to partners via an OCPI connection to have full control over your roaming strategy.
• Hub-based: You can use a roaming hub system by connecting to Hubject, Gireve or any of the new regional hubs, which enables you to reach multiple business partners through one integration point.

You must select between the two options based on your organisation's size and geographic location, and your business development plans.

Step 4: Align Commercial Models and Tariffs

• Determine base tariffs for your own users and dedicated tariffs for your roaming partners.
• Determine who pays roaming costs: the driver, the partner, or a combination of both?
• Leverage tariff data from OCPI and CDR to provide transparent, predictable costs.

Step 5: Launch, Monitor, and Optimise

• Launch with a small scope of roaming to start.
• Monitor usage, revenues, and feedback from your drivers, as well as from roaming and non-roaming sessions.
• Use analytics to improve tariffs, increase capacity, or expand roaming.

FAQs on OCPI, EV Roaming, and Revenue

1. What is the main difference between OCPI and OCPP in one line?

OCPP establishes a connection between chargers and CMS systems, while OCPI enables charging networks to establish roaming connections, tariff agreements and settlement processes with service providers.

2. Do I need to replace my chargers to support OCPI roaming?

Not necessarily. It’s a software-to-software communication. If your chargers are OCPP compliant and your CMS includes support for OCPI, your existing chargers may be able to participate in roaming.

3. How does EV roaming help me increase revenue in more detail?

Roaming provides increased visibility in partner applications, brings in out-of-network users, and increases the utilisation rates of existing chargers. This reduces fixed costs and increases revenue per charger.

4. Is OCPI relevant outside Europe, for example, in India?

Yes. OCPI is widely used in Europe and is now being implemented elsewhere in the world. Indian charging guidelines mention OCPI along with OCPP for interoperable payments and unified user access.

5. Does OCPI handle payments directly?

OCPI does not handle payments as a gateway does; it simply standardises the communication of session and tariff information so that each side can charge correctly. The actual payment can be done by cards, wallets, or local systems like UPI, etc., as long as the backend systems can reconcile with the help of OCPI CDRs.

6. How does Savekar relate to OCPI?

Savekar offers a WhatsApp + UPI-based CMS for properties in India and has implemented an internal OCPI 2.2.1 EMSP simulator for testing its CPO implementation and for future roaming and OCPI ecosystems.

7. Can OCPI help fleets and corporate customers?

Yes. OCPI allows fleets and corporate eMSPs to use a single app or card on many CPOs, while CPOs can still manage tariffs, access, and receive detailed reports and settlements.

Postscript: In‑Depth Technical Notes on OCPI

The OCPI 2.2.1 standard provides a comprehensive technical specification through its RESTful JSON API design, which contains multiple modules that each offer distinct endpoints and data structure requirements.

OCPI Modules and Their Roles

• Versions & Credentials: This module is used for discovering supported versions and modules of the OCPI for a partner, as well as for exchanging credentials for secure communication.
• Locations: This module is used for exposing locations of charge points, connectors, and capabilities, as well as real-time status.
• Tariffs: This module is used for describing complex tariffs that may include a combination of per kWh, per minute, session fees, and time of day.
• Tokens: This module is used for managing driver account identifiers, cards, or app tokens as well as authorisation status.
• Sessions & CDRs: This module is used for tracking live charging sessions as well as generating immutable records for invoicing.
• Commands: This module is used for enabling remote start/stop as well as other control actions.
• Smart Charging (when implemented): This module is used for exchanging constraints and preferences for optimising charging for cost, speed, or green energy share.

Communication Patterns

OCPI supports both push and pull communication models:

• For the pull model, a partner will retrieve the updates (e.g., locations or tariffs) at regular intervals.
• For the push model, the partners will receive the updates (e.g., CDRs or status updates) via callbacks.
• This allows the roaming environment to be adapted to different scaling and reliability needs.

Security and Data Protection

OCPI uses HTTPS and token-based access control for all endpoints.

Regional data protection regulations need to be respected when handling the data by the implementation.

As the OCPI handles personal identifiers, payment-relevant information, and possibly location information, additional security measures for the production environment may include:

• IP whitelisting or a VPN connection between the partners.
• Fine-grained logging and monitoring.
• Role-based access control for back-office applications.

OCPI, Roaming Hubs, and Topology

With the increasing number of CPOs and eMSPs, direct peer-to-peer OCPI implementations may become cumbersome. Roaming hubs based on OCPI 2.2.1 simplify this situation by providing a central point to which many parties can connect once.

This facilitates:

• The integration of new partners without the need to establish n² connections.
• Standardisation of contracts and settlements.
• Version control of the protocol.

For emerging markets like India, this type of OCPI topology can support the fast adoption of roaming services while allowing larger companies to maintain direct peer-to-peer connections.

With an OCPI-enabled backend and a user-friendly local experience like the WhatsApp + UPI charging journey offered by Savekar, CPOs and site hosts can future-proof their infrastructure, leverage the roaming business opportunity, and make their charging stations consistently profitable assets.