Understanding Open Charge Point Protocol (OCPP) - Basics and Interoperability Matters

The UK market for EVs is growing with a whopping CAGR of 8.6% annually. Understanding its growth, technology, and development is quite important. In this article, we will learn about the OCPP protocol in detail! 

Open Charge Point or OCP Protocol enables EV chargers/charging stations to communicate with the central management system. It enables remote management, supports smart charging, and includes security features. This protocol ensures that various brands of chargers in the UK can work together efficiently within a unified network. Just like another remote, OCPP also acts as a universal remote that can control multiple chargers, regardless of the brand. 

The Purpose of the OCPP Protocol

OCPP allows chargers from various manufacturers in the UK to seamlessly connect and interact with diverse software platforms. The following reasons are the major purpose of the OCPP protocol. 

1. Interoperability

With OCPP, you can mix and match chargers from different Charging brands in the UK within the same network. This flexibility means you’re not locked into using one specific type of charger or software.

2. Connects Chargers to Management Systems

OCPP ensures that different brands of EV chargers in the UK can connect and talk to the central system that manages them. Think of it like a common language that all chargers and management systems understand.

3. Standardized Communication

By using OCPP, chargers and central systems can exchange information in a standardized way. This makes it easier to manage and monitor multiple chargers in UK from different manufacturers in one place.

4. Remote Management

OCPP allows operators to control and monitor chargers remotely. This includes starting or stopping charging sessions, checking the status of chargers, and performing maintenance tasks without being physically present at the charging site.

5. Smart Charging

The protocol supports smart charging features, which means it can help manage the distribution of power to avoid overloading the grid and ensure efficient energy use.

6. Secure and Evolving

OCPP includes security features to protect the communication between chargers and central systems. It also gets updated regularly to incorporate new features and keep up with industry changes.

How does OCPP work?

OCPP (Open Charge Point Protocol) operates in the UK by providing a standardized framework that ensures seamless communication and interoperability between various EV chargers and central management systems. Here’s a detailed look at how OCPP works in the UK:

1. Standard Communication Methodology

OCPP establishes a standard communication methodology that allows EV chargers (clients) to interact with central systems (servers) in a consistent and efficient manner. This methodology ensures that different brands and models of EV chargers can connect and communicate effectively with the central management system, promoting interoperability and streamlined operations.

2. Key Components

The Key Components of an OCPP Protocol are as follows. 

• Charge Point (Client): The charge point, or EV charging station, acts as the client in the OCPP framework. It initiates requests and responds to commands from the central system. Tasks handled by the charge point include providing charging services, reporting status, and sending operational data to the central system.
  
  
• Central System (Server): The central system functions as the server, managing a network of charge points. It processes requests from the charge points, issues commands, and collects data for monitoring and analysis. The central system handles tasks such as authentication, authorization, and billing, ensuring efficient network operation.
  
  
• Communication Protocol: OCPP specifies the communication protocols that define how messages are formatted, transmitted, and interpreted between the charge points and the central system. These protocols ensure that both entities can understand and process the information exchanged during their interactions.

Then how is OCPP implemented? Let’s learn in detail. 

3. Types of Implementation

The types of implementation simply mean different methods, software, or technologies used to execute the communication between EV chargers (clients) and central management systems (servers).

SOAP (Simple Object Access Protocol): 

SOAP is an XML-based protocol that defines a standardized way of encoding messages. In OCPP implementations using SOAP, messages are formatted as XML documents and transmitted over HTTP. SOAP provides a robust and extensible framework for message exchange, supporting features such as security and transaction management. However, it can be more complex and resource-intensive compared to JSON-based implementations.

How It Works:

• In SOAP-based OCPP implementations, messages exchanged between the EV chargers and central systems are formatted as XML documents.
• These XML messages are sent over HTTP (Hypertext Transfer Protocol), ensuring structured and extensible communication.
• SOAP provides a robust framework that includes features like security, transaction management, and error handling.

Benefits:

• Extensibility: SOAP's XML format allows for easy addition of new functionalities and fields without breaking existing implementations.
• Security: SOAP supports various security protocols and standards, making it suitable for applications requiring stringent security measures.

Drawbacks:

• Complexity: SOAP messages can be verbose and complex, requiring more processing power and bandwidth compared to simpler formats like JSON.
• Performance: Due to its complexity, SOAP may result in higher latency and lower performance, particularly in scenarios requiring real-time communication.

JSON (JavaScript Object Notation)

JSON is a lightweight data-interchange format that is easy to read and write. OCPP implementations using JSON typically employ HTTP requests and WebSocket for communication. JSON-based implementations are more straightforward and efficient, making them suitable for scenarios where low overhead and fast performance are essential. WebSocket, in particular, enables real-time bidirectional communication, which is advantageous for dynamic and interactive applications.

How It Works:

• In JSON-based OCPP implementations, messages are formatted as JSON objects, which are more compact and easier to process than XML.
• These JSON messages are typically transmitted using HTTP requests or WebSocket, a protocol providing full-duplex communication channels over a single TCP connection.

Benefits:

• Simplicity: JSON’s straightforward syntax makes it easier to implement and debug.
• Efficiency: JSON messages are generally smaller and require less processing power, resulting in faster communication and lower latency.
• Real-Time Communication: WebSocket enables real-time, bidirectional communication, making it ideal for dynamic and interactive applications like EV charging networks.

Drawbacks:

• Limited Extensibility: While JSON is simpler, it may not be as flexible or extensible as XML in handling complex data structures and additional features.
• Security: JSON implementations need to incorporate additional measures to achieve the same level of security provided inherently by SOAP.

Also Read: Everything you need to know about RFID Cards

4. Implementation in the UK

In the UK, the implementation of OCPP ensures that the diverse range of EV chargers installed across the country can be managed effectively by different central systems. This standardization supports the country's goal of expanding its EV charging infrastructure to accommodate the growing number of electric vehicles. The use of both SOAP and JSON protocols allows for flexibility in deployment, catering to various technical preferences and requirements. OCPP’s role in promoting interoperability and efficient management is crucial as the UK continues to enhance its EV charging network to support a greener and more sustainable transportation future.

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History and Evolution of OCPP

The Open Charge Point Protocol (OCPP) has evolved significantly, playing a major role in standardizing communication in the EV charging industry. The development of OCPP began in 2009 by the ELaadNL foundation in the Netherlands. This initiative focused on creating a universal protocol that could facilitate interoperability between different brands of EV chargers and central management systems.

In 2010, the first public version, OCPP 1.2, was released, laying the groundwork for standard communication methodologies. This version set the stage for broader adoption and refinement. In 2012, OCPP 1.5 was introduced, bringing enhancements and addressing the growing needs of the market.

OCPP 1.6, released in 2015, added significant features like smart charging and demand response, which allowed for more efficient energy management. The protocol continued to evolve with OCPP 2.0 in 2018, which introduced enhanced functionalities and support for advanced use cases such as vehicle-to-grid (V2G) interactions. The latest version was OCPP 2.0.1, released in 2020, further improved security measures, expanded smart charging capabilities, and incorporated support for the ISO 15118 standard.

Key Features of OCPP

1. Open Source: Being open-source means that OCPP’s specifications and code are publicly available for anyone to use, modify, and contribute to. This encourages a collaborative environment where developers and industry experts can work together to improve and expand the protocol, driving innovation and ensuring that it meets the diverse needs of the market.

2. Brand Neutral: OCPP is designed to be brand-neutral, meaning it does not favor any specific EV charger brands or software platforms. This neutrality ensures that chargers from different manufacturers can work together seamlessly within the same network, promoting interoperability and reducing vendor lock-in. It allows operators to mix and match chargers and software from different suppliers without compatibility issues.
   
   
3. Free of cost: There are no licensing fees or costs associated with adopting OCPP. This cost-free nature makes it easier for smaller companies and new entrants to the market to implement OCPP, reducing the overall cost of developing and deploying EV charging infrastructure. It encourages widespread adoption and contributes to a more standardized and cohesive EV charging ecosystem.

4. Evolving constantly : OCPP is regularly updated to accommodate the evolving needs of the EV charging industry. These updates, driven by feedback from users and technological advancements, ensure that OCPP remains relevant and capable of addressing current and future challenges. Continuous evolution fosters innovation by incorporating new features and improvements, such as enhanced security measures and support for new use cases like vehicle-to-grid interactions.

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The Importance of Interoperability

Interoperability is an important feature in the EV charging industry as it ensures that all participants use a common protocol, such as OCPP. This "universal language" allows different EV chargers and central management systems to communicate seamlessly, promoting a cohesive and efficient charging network. By supporting tech-agnostic operations, interoperability reduces dependency on specific hardware or software vendors, providing flexibility and preventing vendor lock-in. This enables charging network operators to choose from a variety of compatible products, fostering innovation and improvement. 

Interoperability promotes market competition by allowing the mix-and-match of hardware and software from different manufacturers, driving better quality, performance, and cost-effectiveness in EV charging solutions. This competitive environment ultimately benefits consumers and accelerates the adoption of electric vehicles.

Benefits of OCPP for Stakeholders

The Open Charge Point Protocol (OCPP) offers numerous advantages for stakeholders within the EV charging ecosystem, ranging from flexibility and cost savings to enhanced user experiences and future readiness. Here are some key benefits of OCPP for stakeholders:

• Host and Vendor Flexibility: OCPP reduces vulnerability to the failure of system suppliers by allowing operators to switch between different hardware and software vendors without compatibility issues.

• Cost and Interoperability Advantages: By simplifying network operations and reducing development costs, OCPP ensures that diverse charging infrastructure components can work together seamlessly, making the implementation and maintenance more cost-effective.
• Enhanced Customer Experience: OCPP facilitates efficient account and billing management, improving the overall user experience and ensuring optimal use of the charging infrastructure.
• Future-proof: With capabilities like remote control, smart charging, and integration with new technologies, OCPP ensures that the EV charging infrastructure can adapt to future advancements and industry requirements.

Also Read: Locating Reliable EV Charging Installers in UK

Security Aspects of OCPP

Security aspect of Open Charge Point Protocol (OCPP), ensures safe and reliable communication between EV chargers and central management systems. OCPP implements end-to-end encryption to secure data transmission, protecting sensitive information such as user credentials, transaction details, and operational commands from unauthorized access and tampering. This encryption ensures that data remains confidential and intact as it travels between the charging station and the central system.

OCPP also addresses common attack scenarios, such as man-in-the-middle attacks, denial of service (DoS) attacks, and data breaches. By implementing robust authentication mechanisms and secure communication channels, OCPP minimizes the risk of these attacks and enhances the overall security posture of the EV charging network.

Recent revisions of OCPP have introduced updated security guidelines to keep pace with emerging threats and technological advancements. These updates include recommendations for secure boot processes, firmware signing, and enhanced encryption standards. By continuously evolving its security measures, OCPP ensures that the EV charging infrastructure remains resilient against cyber threats, safeguarding the interests of operators, service providers, and end-users alike.

Now that we are quite familiar with the security aspects of OCPP, let’s find out its key functional blocks. 

Key Functional Blocks of OCPP

OCPP Protocol encompasses several functional blocks that ensure efficient and secure operation of EV charging networks. These blocks cover a wide range of functionalities, from security and authorization to tariff management and smart charging. Here are the key functional blocks:

1. Security, Provisioning, and Authorization
   

• Security: Implements end-to-end encryption and robust authentication mechanisms to protect data transmission and prevent unauthorized access.
• Provisioning: Involves the initial setup and configuration of charging stations to ensure they are properly connected and managed by the central system.
• Authorization: Manages user access to charging stations, ensuring that only authorized users can initiate charging sessions.
  

2. Local Authorization List Management and Transactions
   

• Local Authorization List Management: Maintains a local list of authorized users or vehicles, enabling charging stations to function even when offline.
• Transactions: Handles the initiation, monitoring, and completion of charging sessions, ensuring accurate tracking and billing of energy consumption.
  

3. Remote Control, Availability, and Reservation
   

• Remote Control: Allows operators to manage and control charging stations remotely, including starting and stopping sessions and adjusting settings.
• Availability: Monitors the status of charging stations to ensure they are operational and available for use.
• Reservation: Enables users to reserve charging stations in advance, ensuring availability when needed.
  

4. Tariff and Cost Management, Metering, and Smart Charging
   

• Tariff and Cost Management: Manages pricing structures and calculates the cost of charging sessions based on various tariffs and billing models.
• Metering: Measures and records the amount of energy delivered to each vehicle during a charging session.
• Smart Charging: Optimizes energy use by adjusting charging rates based on grid demand, availability of renewable energy, and other factors.
  

5. Firmware Management, Diagnostics, and ISO 15118 Certificate Management
   

• Firmware Management: Allows for remote updates of charging station firmware, ensuring they have the latest features and security patches.
• Diagnostics: Provides tools for monitoring and diagnosing issues with charging stations, facilitating maintenance and troubleshooting.
• ISO 15118 Certificate Management: Manages digital certificates required for secure communication between EVs and charging stations, supporting features like Plug and Charge.

These functional blocks collectively ensure that OCPP provides a comprehensive and secure framework for managing EV charging infrastructure, enhancing the user experience and operational efficiency.

Now the question arises, what is the certification process in OCPP?

OCPP Certification Process

The OCPP certification process ensures that EV chargers and central management systems meet the OCPP standards, promoting interoperability and reliability across different products. It involves conformance tests using the OCPP Compliance Testing Tool to verify adherence to specifications, performance measurements in laboratory environments to assess response times, stability, and handling of various scenarios, and current certification, which as of now, only includes OCPP 1.6 versions. Certification services are available in different regions, allowing local manufacturers to certify their products, confirming their compliance with OCPP standards, and enhancing their market credibility and acceptance.

Through the years, there have been different launches of versions in OCPP. Let’s find out in detail.

Differences Between OCPP Versions

OCPP 1.6 and OCPP 2.0.1 represent significant milestones in the evolution of the Open Charge Point Protocol, each introducing critical features to enhance EV charging infrastructure. 

OCPP 1.6, released in 2015, brought in essential functionalities such as smart charging and demand response. Smart charging allows the efficient management of energy use, optimizing charging times and power levels based on grid conditions and availability. Demand response capabilities enable the charging stations to adjust their operations according to signals from the grid, helping to balance demand and supply and avoid overloading the electrical infrastructure.

On the other hand, OCPP 2.0.1, released in 2020, builds on the features of OCPP 1.6 and introduces several advanced functionalities. One of the key improvements is enhanced security, including features like secure boot and firmware signing, which protect against unauthorized access and cyber threats. 

OCPP 2.0.1 also supports ISO 15118, a standard for vehicle-to-grid communication that enables seamless plug-and-charge capabilities, where EVs automatically authenticate and authorize charging sessions. This version offers better charging management, with more detailed session reports, improved transaction handling, and enhanced support for smart charging scenarios, including bi-directional power flow for vehicle-to-grid (V2G) interactions. These enhancements make OCPP 2.0.1 a more robust and future-proof protocol for modern EV charging needs.

Conclusion

Throughout our discussion, we have explored the Open Charge Point Protocol (OCPP) in detail, including its definition, purpose, and key features. OCPP is an open-source, neutral, and cost-free protocol that ensures interoperability among various EV chargers and central management systems, facilitating seamless communication and operation within the EV charging ecosystem. 

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