Problem To Be Solved
As the technology for electric vehicles continues to improve they are becoming a more common sight all over the world. Dotted around most European countries there are electric vehicle charging stations on major routes, in hotel car parks and often at service stations. In Ireland most of these charging stations are currently free providing an incentive for users to adopt electric vehicles. As the technology becomes more widely adopted this model becomes unsustainable; as such a billing system must be introduced and there will likely be various companies offering charging services with competing price schemes. This requires the updating or replacement of existing charge points to incorporate tracking customer IDs, usage times, electricity used etc.
The purpose of this project was to create a client-server system that would be able to track customer data and send it to a central point so that this information could be used to create bills. A requirement on the client end was the need to be able to identify and authenticate users securely, track the power consumed in charging and the time spent charging. The server end needed to retain data on valid users for authentication, keep a record of each customer’s usage and keep information on each charging station such as the configuration and different payment schemes.
The open charge point protocol (OCPP) was chosen as the standard for communication between client and server. This protocol is an initiative of the E-Laad foundation in the Netherlands and has been widely adopted across Europe and Asia. Using an open charging protocol has many advantages for the customer, it helps facilitate interoperability between charging stations allowing many providers to use the same charging station. This means that the different providers can compete on price and services offered, promoting healthy market competition.
When looking at programming languages with which to develop the client and server software it was important that it supported high level concepts such as threading and compatibility with different operating systems. With this in mind the Mono Framework was chosen, Mono is an open source version of the C# language. The software can be run on Windows, Mac or Linux based systems, allowing the client-server software to be deployed on almost any existing system, lowering the cost of installation and reducing complications.
Impact & Benefits
By implementing the OCPP in the system we ensured that it can be adopted in Ireland and across Europe. The system has several security features including access control based on RFID. It has been designed to support additional features that will allow for an open competitive charging station market as this will enable each provider to differentiate themselves. For example, by having several different payment schemes available or by offering different levels of service. One optional feature is to allow white-listed premium customers to charge their vehicle even when a network connection is lost. With further development the system could support features such as:
- A reservation system to allow for reservation in specific time slots
- Smart Charging to allow for the car to be used as a power source during periods where the grid is under strain