What is Eichrecht?
The German calibration law, commonly known as “Eichrecht”, applies to all measuring devices, including electricity meters on EV charging stations. In the context of EV charging, the main sentiments behind the law are to ensure the accurate measurement of energy used for EV charging, and transparency to the consumers so they can validate their EV charging bills.
Eichrect is actually composed from several regulations:
- Calibration Law (German: Mess- und Eichgesetz – MessEG): This law provides the foundation for deploying measurement instruments and emphasizes the need for accurate measurement.
- Calibration regulation (German: Mess- und Eichverordnung – MessEV): These regulations include provisions and guidelines for a variety of meters, including electricity meters used in EV charging stations, describing how the meters should be calibrated.
- Regulations on price indication: These regulations aim to ensure transparency and clarity to consumers about what they are being billed for and dictate how pricing should be indicated.
What are the requirements of Eichrecht for EV charging?
Charging scenarios
Eichrecht applies when the driver must pay for EV charging, so clearly, this includes public and semi-public charging scenarios. If an employee must pay for EV charging at private workplace chargers, then those must also comply with Eichrecht. Workplace chargers where charging is free for employees, and home chargers solely for private use are exempt.
Accuracy and transparency
The charging stations must have an energy meter that is certified by the National Metrology Institute of Germany (Physikalisch-Technische Bundesanstalt – PTB), and that periodically calibrates the amount of energy delivered. The charging station must display the amount of energy for which the driver is being charged, as well as the date and time. The driver must be able to verify the charges through an external app or web portal.
Energy charges may only be based on the quantity of energy used. Flat fees are only allowed for monthly or yearly plans. Flat session rates and time-of-use tariffs are not allowed. Additional fees such as charging time and parking time are allowed but must be listed separately on the invoice.
Data and security
Either the data meter, or a separate display must be visible to the driver, and must show the amount of energy consumed and a timestamp (date and time). Before being sent to the Charge Point Management System (CPMS) in the back end, meter data must be signed with a private key which is securely stored on the charger and encrypted. This ensures the values are original and authentic, i.e., they have not been tampered with. In turn, the CPMS must store the following data points:
- The energy delivered in each transaction
- Time stamps
- Unique ID of the EVSE or the meter
- Customer ID and/or transaction ID
- Digital signature of the dataset
How is reliability guaranteed to consumers
Eichrecht goes beyond just the electricity meter and displaying the amount of energy delivered. The back-end systems must be able to ensure that values used for billing are original and authentic, and the CPO and eMSP must provide customers with a way to verify these values. Since data transmitted from the EVSE to the back-end platform is signed with a private key, it can be verified using the corresponding public key. The public key must be displayed on the charging station and/or provided on the invoice delivered to the customer. Given the public key, customers can verify the meter values using an independent application such as Transparency software available from the Software Alliance for E-mobility (S.A.F.E).
Driivz EV Charging and Energy Management Platform is Eichrecht-compliant and enables network operators to validate charge session data, and to share it with drivers so they can be fully compliant with Eichrecht.
