German Calibration Law – A Brief Introduction

A woman using the screen on an electric charger

Many countries have introduced legislation regarding calibration of meters and pricing for electric vehicle charging. CPOs and EMSPs need to follow these laws closely to ensure compliance in the markets in which they operate.

In the European Union, Article 4, Point 10 of the Alternative Fuels Infrastructure Directive (AFID) stipulates that EU member states need to ensure prices charged by operators of public charge points are ‘reasonable, easily and clearly comparable, transparent and non-discriminatory.’

Following this directive, EU member states have created their own laws to increase price transparency in EV charging. In Germany, the two main laws for e-mobility companies are:

  • Mess- und Eichgesetz (MessEG) – According to this law, charge stations must meet official calibration requirements and provide clear information to all parties on the amount of electricity supplied. The MessEG applies to all charge stations where users pay for their electricity consumption.
  • Preisangabenverordnung (PAngV) – This law stipulates that the price for a charge session must be displayed and calculated per unit of energy (kWh) supplied to the electric vehicle.

To comply with these laws, CPOs and EMSPs need to consider a range of factors on both the hardware and software side.

Charging hardware

From a hardware perspective, CPOs who offer public or semi-public charging need to choose charge stations that have been approved under the Mess- und Eichgesetz (measurement and calibration law). They should also consider whether the hardware can exchange data with back-end software used to manage the network, as hardware integration is essential for full calibration law compliance.

Pricing model

While flat fees per session and tariffs based only on the time spent charging are no longer permitted, e-mobility companies in Germany can choose any of the following pricing models:

  • price per unit of electricity consumed (kWh)
  • price per unit of electricity consumed (kWh) + time component
  • starting fee + price per unit of electricity consumed (kWh) + time component
  • flat rate model based on monthly or yearly payments
  • price calculated based on the time spent parking (regardless of time spent charging)

Price transparency

According to the Alternative Fuel Infrastructure Directive (AFID) and MessEG, e-mobility companies also need to communicate charging information to the driver in a transparent way.

For CPOs and EMSPs in the German market, this means that they need to keep a detailed record of the amount of energy supplied during each charge session.

This information must be shared with drivers on their invoices, while every effort is made to protect sensitive user data from third parties.

Challenges in complying with calibration law

In the German market, Eichrecht compliance is essential for e-mobility players. On a practical level, they face a number of challenges to achieve compliance, however, including network complexity and multiple use cases.

Network complexity

While the EV charging landscape is constantly changing, many CPOs and EMSPs use roaming to give drivers access to a large network of charge stations.

However, widely used roaming protocols like OCPI and OICP are not yet designed to transfer data on the amount of energy consumed between CPOs and EMSPs via charge detail records. Future revisions of the protocols will probably include this information, but for now, CPOs, EMSPs, and software companies are implementing bespoke solutions to ensure that the required information can be shared nonetheless.

Multiple use cases

As the uptake of electric vehicles continues to increase, so does the versatile use of charge stations. Whereas previously companies would install charge stations for exclusive use by their EV fleet, that same infrastructure may now be used to charge an employee’s private car and visitor’s electric vehicle.

Man grabbing EV charger and looking at his phone

Similarly, home chargers intended only for use by residents in a building may now be opened to the public during certain times, for example when residents are out at work or during periods when charger utilisation is low.

Depending on the business model of the CPO, Eichrecht compliance may be needed for some charge sessions (but not for others). It could also apply to limited subset of chargers within the CPO’s network.

GreenFlux’s solution

To comply with Eichrecht, CPOs can install chargers with an in-built, calibrated screen to display the energy consumed by electric vehicles during charging. However, some hardware manufacturers have opted not to equip their charge stations with screens and instead provide meter data through a connection with charge station management software.

Until now, neither solution allows for data to be shared directly via roaming networks – yet this is essential for full Eichrecht compliance.

The solution provided by GreenFlux allows for Eichrecht-compliant roaming by securely transferring signed meter values from the CPO to the EMSP. Our backend receives meter data from charge stations via the OCPP protocol, and we safely store it in our database.

As most common roaming protocols do not yet support the transfer of signed meter values, our solution shares the data with EMSPs via a URL that is included in the ‘remarks’ field in the charge detail record (CDR).

How our Eichrecht-solution works for EMSPs

An EV driver has just completed a charging session at a public charge station in Germany operated by a CPO using GreenFlux software. The driver receives an invoice for the charged amount and would like to check that the meter value reading on his invoice is correct. The driver contacts the EMSP with this request.

If the charge station has a built-in meter-value reader, the driver can be directed to check locally at the charge station.

If the charge station sends signed data, then the EMSP customer support team can locate the signed meter data in the URL included in the charge detail record sent via our platform. This information can be copied as-is and sent to the customer.

Our software makes this process as secure and efficient as possible for EMSPs, and helps with full Eichrecht compliance. Read our whitepaper to learn more about this solution and discover what Eichrecht is for your charging business.