Welcome to our FAQ section. Here you will find answers to frequently asked questions about the ZEREZ register (Central Register for Unit and Component Certificates). This FAQ section will be continuously updated. Please contact us if you have any questions, suggestions or requests.
– What is ZEREZ?
ZEREZ stands for the Central Register for Unit and Component Certificates. From 1 February 2025, manufacturers of units or components for electrical generation systems are obliged to register the unit and/or component certificates issued to them in ZEREZ. The register contains certificates for all voltage levels.
– Who is affected by ZEREZ?
Anyone who wants to connect a new energy generation system to the grid. From 1 February 2025, applicants for operating licences will only submit the ZEREZ ID instead of certificates. Grid operators and manufacturers of units or components for electrical generation systems will be obliged to use ZEREZ from 1 February 2025.
Unit and component certificates for generation plants are listed in ZEREZ. In contrast, generation plants are recorded in the market master data register.
From 1 February 2025, the validity check of unit and component certificates and the transmission of performance parameters as part of the operating permit procedure will be carried out digitally via ZEREZ.
– Why ZEREZ?
As a centralised database, ZEREZ simplifies, digitalises, accelerates and standardises communication between the parties involved in the certification of units and components and in the application for operating permits.
ZEREZ was realised at the suggestion of and in cooperation with various groups of market participants such as network operators and manufacturers.
– What is the current status of ZEREZ?
ZEREZ is in voluntary operation until 31.01.2025.
From 1 February 2025, manufacturers of units or components for electrical generation systems are obliged by the Ordinance on the Verification of Electrotechnical Characteristics of Energy Systems to register the unit and/or component certificates issued to them here.
– Who is subject to the obligation and what does it involve?
From 1 February 2025, manufacturers of units or components for electrical generation systems are obliged to register the certificates issued to them in ZEREZ (Section 4 (3) NELEV). From 1 February 2025, grid operators are obliged to use only the registration numbers (ZEREZ ID) from the ZEREZ when connecting energy generation systems to the electrical grid.
From 1 February 2025, the verification of the validity of unit and/or component certificates and the transmission of performance parameters as part of the operating permit procedure via ZEREZ will expire. You are not authorised to request information on the unit and component certificates by any other means than via the register (Section 4 (10) NELEV). Accordingly, plant operators who wish to connect a new energy generation plant to the grid must submit this register number during the operating licence procedure (§ 4 Para. 9 NELEV). This simplifies the previous procedure and eliminates the need to send physical documents between plant operators, certification bodies and grid operators.
Access to the register numbers (ZEREZ-ID) is also possible without registration.
– What are unit and component certificates?
Unit and component certificates are proof of the electrical properties of generating units and electrical components. They are issued by accredited certification bodies and play a crucial role in the grid connection process and system certification. These documents ensure that only compliant systems are connected to the electricity grid and form an essential basis for grid calculations and the design of grid connection points.
– Is there mandatory information for the upload and who has defined it?
Yes, depending on the type of certificate and the certified device, certain parameters must be specified in order for the certificate to be entered in the register. VDE-FNN has specified which these are. The mandatory parameters are labelled in columns B, C, D and E of the list of grid connection values.
The lists of grid connection values can be downloaded here.
– Are there definitions for the individual parameters?
Yes, the definitions and where they can be found in the regulations are shown in column G of the list of grid connection values. You can download the current revision of the list of grid connection values here.
– Are generation plants recorded in ZEREZ?
No, unit and component certificates for generation plants are listed in ZEREZ. Generation plants are recorded in the market master data register.
– What do I do if I cannot find a unit or component in ZEREZ?
Manufacturers of units or components for generation plants must register the unit or component certificates issued to them in ZEREZ from 1 February 2025 (see NELEV Section 4 (3)).
If a certificate is not listed in the ZEREZ, please contact the respective manufacturer.
– What requirements must a certification body meet in order to issue unit and component certificates?
Certification bodies that issue unit and component certificates for power generating plants must meet both national and European legal requirements.
According to § 4 of the Verification Ordinance (NELEV) and the relevant technical regulations of VDE FNN, certification bodies are required to demonstrate accreditation in accordance with DIN EN ISO/IEC 17065. This accreditation is carried out by a national accreditation body, in Germany typically the Deutsche Akkreditierungsstelle GmbH (DAkkS). The scope of accreditation must explicitly include the performance of conformity assessment procedures for generating units and plants as well as their components in accordance with the specifications of the VDE FNN.
In addition, COMMISSION REGULATION (EU) 2016/631 of 14 April 2016 establishing a network code on requirements for grid connection of generators (RfG Regulation) sets binding requirements regarding the qualification of certification bodies. According to Article 30(1) of the Regulation, certification bodies must be approved or accredited under a procedure recognized at the European level by the national member of the European cooperation for accreditation (“EA”) established under Regulation (EC) No. 765/2008 of the European Parliament and of the Council (6). They must demonstrably possess the necessary competence, independence, and impartiality to carry out conformity assessments in line with the requirements of the RfG Regulation.
The certification body must ensure that it complies with the respective national implementation provisions of the RfG Regulation and, in particular, correctly applies the conformity assessment procedures set out in Annex IV of the Regulation. This includes, among other things, the proper issuance of unit and component certificates as proof of compliance with grid connection requirements.
Summary:
Recognition of certificates in Europe
In order to be allowed to issue unit and/or component certificates that are recognised as proof of compliance with the technical requirements in the grid connection process within the EU, certification bodies must meet both national and European requirements. (See: ‘What requirements must a certification body meet in order to issue unit and component certificates?’)
– What does ‘certificate verification’ mean?
The certificate verification is a check between the certificate holder (manufacturer) and the issuing certification body. The correct entry of the data from the physical certificate in the central register is checked.
The status says nothing about the validity of the certificate or document. It merely provides assurance that the entry has been checked by both parties and helps to rule out transmission errors.
– Where does the status of the certificate come from?
Manufacturers of generating units must undergo the certification process in accordance with DIN EN ISO/IEC 17065. As part of this process, test reports and measurements must be prepared by DIN EN ISO/IEC 17025 accredited measuring institutes.
The status of a unit or component certificate is determined by the commissioned certification body based on the following regulations:
– What does the certificate status indicate?
Unit and component certificates can have the following statuses (see FGW TG 8)
– What is the purpose of the ZEREZ register number (ZEREZ ID)?
ZEREZ links all unit certificates to a unique register number. The ZEREZ register number (ZEREZ ID) is used to make the grid connection process more efficient. In future, it will be sufficient to enter this register number in the grid connection process and the grid operator will be able to retrieve the necessary data.
– How is the ZEREZ register number (ZEREZ-ID) structured?
The ZEREZ register number, for example ‘ZE-R018-RV36-0001’, is made up of various parts:
– Is every ZEREZ ID linked to a certificate?
No, ZEREZ IDs are not exclusive to certificates. ZEREZ IDs are also given to manufacturer declarations and prototypes. These can be differentiated by the type of document listed in the document information in the public register or by attribute 1.12 (type of document) for API querys by eligible parties.
– Who can register?
Registration is possible for manufacturers of power generation systems, grid operators, certification bodies and planners, installers and operators of power generation systems.
– Are there any fees for registering with ZEREZ?
No – ZEREZ is free of charge due to the requirements of the new regulation by the NELEV Amendment Ordinance. There are no fees for registering and using the basic functions of the register.
– How do I create a user account?
You can create a user account via the ‘Registration’ tab on the ZEREZ website. Follow the steps indicated to create your account. When entering your company name, address and contact details, please ensure that the information is correct and that it is spelt correctly. If you receive an error message stating that your company/organisation already exists, make sure that it has not already been created by other people. You can then be added to the organisation via the ‘User administration’ tab and the ‘Invite user’ button.
– I have forgotten my password. How can I reset it?
Under the login page you will find the option ‘Forgotten password’. Follow the steps below to reset your password.
– Can a company register multiple users?
Yes – Registration takes place in the register. The first person to register is also the ‘main admin’ and can add further team members.
To do this, use the ‘Invite user’ button in the ‘User administration’ tab.
– Do I have to register as a planner/installer/operator?
No – Registration is not required to view the register. Advanced functions are only available after successful registration.
– Which browser is recommended for ZEREZ?
ZEREZ is optimised for Google Chrome.
– How do I upload a certificate?
Once you have successfully logged in, as a user of the ‘Manufacturer’ and ‘Certification body’ groups, you can use the ‘Upload certificate’ function to transfer the certificate in digital form to the ZEREZ system. You can enter the parameters manually or fill in the Excel template ‘List of grid connection values’ in the appropriate form and have the values read in. The lists of grid connection values can be downloaded here.
– Is there mandatory information for the upload and who has defined it?
Yes, depending on the type of certificate and the certified device, certain parameters must be specified in order for the certificate to be entered in the register. VDE-FNN has specified which these are. The mandatory parameters are labelled in columns B, C, D and E of the list of grid connection values. The lists of grid connection values can be downloaded here.
– Who can upload certificates?
After successful registration, manufacturers and certification bodies can upload their certificates to the register using the ‘Upload certificate’ function in the ‘Units and certificates’ tab.
– Who can see which data?
Different user groups have different rights to view data on ZEREZ.
In future, registered users will be able to request access to non-public data from the manufacturer. Manufacturers will be able to authorise or reject these requests accordingly.
VDE-AR-N 4105:
The cover sheet of the verification document (VDE-AR-N 4105 – Annex E.4/E.5) and the certificate for integrated network and system protection or the test report for NA protection (VDE-AR-N 4105 – Annex E.6/E.7) are publicly accessible. This also applies to the list of grid connection values.
VDE-AR-N 4110/20/30:
The cover sheet of the verification document (1.16) and certain data are publicly available. (1.01 – 1.16,1.18, 1.20, 1.21,1.25, 1.28 and 1.68 (IDs list of grid connection values))
Registered users with the role of grid operator always have access to the entire list of grid connection values.
– Is there a digital interface to ZEREZ?
Yes, there is a digital interface to ZEREZ. This is currently only available for network operators.
– As a network operator, where can I get the access data for the digital interface?
The administrator of your organisation can manage the access data for the API directly on the website.
You will find this option on the ZEREZ website in the ‘User administration’ tab under ‘API key’.
– Do I have to register my PV system in ZEREZ?
No. Unfortunately, there are currently some misleading reports about ZEREZ in circulation. As the operator of a PV system or another existing system, ZEREZ does not impose any new obligations on you. The obligation to register only applies to manufacturers of energy generation units and not to operators of existing systems (see NELEV Section 4 (3)).
In future, your grid operator will only want to know the ZEREZ ID of the units and components you have planned as part of the grid connection process. They can then use this ZEREZ ID to retrieve all the information they need for their grid planning. This is intended to simplify and speed up the grid connection process for everyone involved. As the operator of a PV system, you only need ZEREZ if you want to connect a new energy generation unit to the grid from 1 February 2025 and then only to look up the ZEREZ ID of the units and components you are using in order to be able to communicate this to your grid operator (see NELEV Section 4 (9)).
– I would like to connect a balcony PV system to the electricity grid. Do I have to send the system certificate to the grid operator?
No, this is not necessary. It is not permitted to use products in Germany that do not have a CE mark, German operating instructions or a European contact person or that do not fulfil the technical requirements. However, since last year, balcony PV systems have only had to be registered in the Federal Network Agency’s Market Master Data Register (MaStR). Since then, registration with the grid operator is no longer necessary (exception: the operator would like to be remunerated for the electricity generated in this way). Registration was simplified as part of the solar package in April 2024; it is now limited to a small amount of data that is easy to enter. In this respect, the obligation under Section 4 (9) NELEV – relating to the operating licence procedure – that the operator of a generation plant must transmit the registration number of the unit or component certificate from the ZEREZ to the responsible grid operator as part of this operating licence procedure is obsolete for balcony power plants. The fact that this obligation to transmit this information to the grid operator does not, of course, mean that plants that do not fulfil the technical requirements may be operated without a corresponding certificate.
– My company manufactures balcony PV systems. Do the unit certificates for these systems have to be registered in ZEREZ?
Yes, the obligation of manufacturers of units or components for power generation systems in accordance with Section 4 (3) sentence 1 NELEV to submit the unit or component certificates issued to them to ZEREZ for registration also applies to manufacturers of balcony PV systems. It is not permitted to sell products in Germany that do not have a CE mark, German operating instructions or a European contact person. In addition to these formal requirements, technical requirements must also be met. The unit and component certificates to be registered in ZEREZ contain the necessary information to prove that the technical requirements have also been met.
– Do unit and/or component certificates for storage systems also have to be uploaded to ZEREZ?
According to NELEV Section 4 (3), the obligation to upload in the ZEREZ only applies to unit and component certificates.
According to VDE-AR-N 4105, every generation unit that is to be connected to the public grid is certified. The inverter is considered a generation unit. This means that the unit certificates are issued for the inverter and battery storage systems without an integrated inverter cannot be certified separately.
Safety certificates (such as UN38.3, IEC62619, IEC62477-1, IEC62040, CE EMC and IEC63056) are often required by the grid operator. These relate to the individual components of the battery storage system, but are not unit or component certificates.
However, it is primarily the inverter that is decisive for a compliant connection to the distribution grid. For fully integrated energy storage systems with alternating components, it is usually sufficient if the certificates of the inverter are submitted.
To summarise, only the unit certificate or the ZEREZ ID of the inverter used is usually required from ZEREZ to connect a storage system to the grid.