Grid codes define what a V2G unit must do. OCPP 2.1 and ISO 15118-20 are how those rules actually travel, from a grid operator’s control room to the inverter inside your car.
Excellent explanation of a complex subject. In my role as technical editor for the Open Charge Alliance I am currently writing a paper on how to map the OCPP 2.1 DER control functions onto the ISO 15118-20 Amd. 1 functions. OCPP 2.1 was released in January 2025 when ISO was in the process of defining the Amendment 1. At that time the content of the OCPP DER control had been coordinated with the ISO working group. During 2025, however, the Amendment was overhauled, because IEC and SAE could not agree on a joint approach. The AC_DER service was changed into two completely different services AC_DER_IEC and AC_DER_SAE. As a consequence the mapping from OCPP to ISO is not as straightforward anymore as it used to be. The mapping to AC_DER_SAE is still okay (because OCPP 2.1 DER was inspired by IEEE 2030.5, which is prescribed by SAE J3072), but the mapping to AC_DER_IEC needs some conversions (e.g. some DER curves need to be represented as a droop in AC_DER_IEC). The ISO 15118-20 Amd. 1 is not yet final, so we may hold the publication of this paper until the official publication of the amendment.
Thank you for these insights, Franc, really appreciate it. I hope the Amd. 1 is going to be published in the next couple of months and I'm keen to get my hands onto the paper you're writing. Thanks for all the great work you're doing as a technical editor for the OCA, keep up the great work!
These articles about V2G are invaluable. They bring so many aspects together in one place. After reading I feel like a V2G expert - and got a headache from processing all the information ;) Thank you for sharing your incredible knowledge and experience!
Thanks so much for this very kind feedback! I'm really glad my articles prove to be such a valuable resource for so many people in this industry. Hope I can do my bit to help accelerate the update and scale of interoperable V2G.
Excellent explanation of a complex subject. In my role as technical editor for the Open Charge Alliance I am currently writing a paper on how to map the OCPP 2.1 DER control functions onto the ISO 15118-20 Amd. 1 functions. OCPP 2.1 was released in January 2025 when ISO was in the process of defining the Amendment 1. At that time the content of the OCPP DER control had been coordinated with the ISO working group. During 2025, however, the Amendment was overhauled, because IEC and SAE could not agree on a joint approach. The AC_DER service was changed into two completely different services AC_DER_IEC and AC_DER_SAE. As a consequence the mapping from OCPP to ISO is not as straightforward anymore as it used to be. The mapping to AC_DER_SAE is still okay (because OCPP 2.1 DER was inspired by IEEE 2030.5, which is prescribed by SAE J3072), but the mapping to AC_DER_IEC needs some conversions (e.g. some DER curves need to be represented as a droop in AC_DER_IEC). The ISO 15118-20 Amd. 1 is not yet final, so we may hold the publication of this paper until the official publication of the amendment.
Thank you for these insights, Franc, really appreciate it. I hope the Amd. 1 is going to be published in the next couple of months and I'm keen to get my hands onto the paper you're writing. Thanks for all the great work you're doing as a technical editor for the OCA, keep up the great work!
This is one of the technically deeper articles that I read lately in the space, yet explained in simple words. Thanks @Marc Mültin . Keep sharing.
Thanks for sharing and the kind feedback!
These articles about V2G are invaluable. They bring so many aspects together in one place. After reading I feel like a V2G expert - and got a headache from processing all the information ;) Thank you for sharing your incredible knowledge and experience!
Thanks so much for this very kind feedback! I'm really glad my articles prove to be such a valuable resource for so many people in this industry. Hope I can do my bit to help accelerate the update and scale of interoperable V2G.