What is OCHP?

Last update of this website: 11-06-2020

The Open Clearing House Protocol enables boundless electric vehicle charging across charging station networks. Using OCHP, service providers for EV charging can connect to infrastructure providers in order to provide access to their network.

Open Clearing House Protocol (OCHP) has the purpose to connect market actors in the field of electric mobility charging infrastructure. This protocol enables parties to communicate between their own back-end system (like a CMS) and a clearing house system, in a simple way.

OCHP is an open source protocol. It offers a uniform, SOAP based, interface solution. Everyone is free to implement and to actively participate in the development of the protocol, which is rapidly becoming the free international standard in the electric vehicle market. The current protocol version is 1.4.

Protocol updates

June’s Feature Friday #4: Going Live

In this last post of the June Feature Friday, we’re looking at the OCHP Direct interface, the OCHP extension allowing for direct communication between the actors connected to the clearing house.

Why a Direct Interface?

While the central hub focus of OCHP allows for easy technical integration with a wide array of partners and enables roaming with a reduced amount of development need on the side of the connected backends, many of the more advanced use-cases such as giving live feedback for the driver on his session from the charger require a direct, live interface. For this, OCHP 1.3 introduced the first version of OCHP Direct, which will be aligned to the same version number (1.5) in the upcoming OCHP release.

In the current version, a wide number of use-cases is already covered, including but not limited to:

  • Trigger Remote Start/Stop Transactions
  • Reserving charging spots
  • Getting live data about charge point availability directly from the backend

There is already a range of information that the CPO can provide to the EMP via the “Inform Provider” method, giving live updates on a charge-in-progress to display in an app, for instance.

Going live

In order to facilitate protocol alignment with the market, and cover additional use cases, OCHP Direct 1.5 will include methods for live validation of existing tokens on an EMP endpoint. This means that even for use-cases where a customer swipes a card in front of a charger, the CPO checks via OCHP direct if that card is valid. As discussed in the first installment of the OCHP Feature Friday, these tokens will have the “Live Authorization” attribute to let the CPO know whether it SHALL or CAN be validated.

Currently, the recommendation is to use the OCHP Direct Session ID as the Authorization token for the CDR that follows it. However, with this change, a new optional field will be added to the CDR called “DirectID” which SHALL include the Session ID if one existed. The token field can then either contain the customer credentials if they were used, or otherwise the session ID again to ease backwards compatibility.

Read all our protocol updates.