ZEREZ is a centralized registry for unit and component certification launched by the German government in 2024 to enhance the safety and reliability of the power grid. Since its launch, the system has become an essential tool for grid connections by helping grid operators, certification bodies, and manufacturers manage equipment certification information efficiently. Beginning February 1, 2025, all components and units of photovoltaic (PV) power generation and energy storage systems in Germany must be registered in ZEREZ (the Centralized Registry for Unit and Component Certification). Unregistered equipment will be prohibited from connecting to the grid.
Ⅰ. What is ZEREZ?
ZEREZ is a mandatory registration platform introduced by Germany to strengthen the safety and reliability of the power grid. Launched in April 2024, the system has become an essential tool for grid connections. It enables grid operators, certification bodies, and manufacturers to manage equipment certification information more efficiently. Key components of PV systems (like microinverters and energy storage devices), along with other power-generating units, require certification and registration within the ZEREZ system. This measure simplifies the review process for grid operators and ensures that all equipment complies with safety and technical standards.
Ⅱ. Which systems and components require a ZEREZ certificate?
According to the new regulations, starting February 1, 2025, all units and components of PV and energy storage systems must complete ZEREZ registration. Equipment that is not registered will be unable to connect to the grid. The ZEREZ requirements affect a large number of power generation systems and their components, as outlined below:
- Systems on the low-voltage grid: For typical private PV systems intended for personal use, the inverter usually only requires a unit certificate.
- Systems on medium-, high-, and extra-high-voltage grids: Larger systems require additional certificates for individual components. A system certificate is required for a feed-in capacity exceeding 270 kW.
- Performance limits: Systems with a total output of up to 500 kW and a maximum feed-in capacity of 270 kW do not require a system certificate. A simplified declaration of conformity, which can primarily be provided through certificates from the unit and component manufacturers, is sufficient. Systems exceeding these performance limits must undergo comprehensive certification.
- Additional components:
- Battery storage systems.
- Combined heat and power (CHP) plants and other power generation systems.
Ⅲ. How is ZEREZ registration performed?
- Certificate Upload by Certification Bodies: On the ZEREZ platform, certification bodies (including equipment manufacturers) are responsible for uploading the relevant certificates. Each registered certificate receives a unique registration number (ZEREZ-ID).
- Certificate Lookup and Verification: Grid operators can use the ZEREZ-ID to verify that equipment meets technical requirements. Users simply need to provide the ZEREZ-ID to their grid operator, eliminating the need to answer cumbersome certification questions.
- Public Data and Privacy Protection: Basic data for low- and medium-voltage systems will be publicly viewable by all registered users on the ZEREZ platform. Data for equipment on higher-voltage grids will only be accessible to registered users.
Ⅳ. What is the difference between a unit certificate and a system certificate?
A unit certificate typically applies to a single component, such as an inverter in a PV system. It certifies that the individual component complies with specific standards and technical guidelines. A system certificate, on the other hand, is required for larger projects. It covers the entire system, including all connected components, and confirms their proper interaction. In many cases, a comprehensive system certificate is required for systems with a feed-in capacity over 270 kW and an installed capacity up to 500 kW. For smaller, private PV systems, however, a unit certificate is usually sufficient.
Ⅴ. Do ZEREZ requirements also apply to balcony power plants?
Yes, the ZEREZ requirements also apply to balcony power plants (small, plug-in solar systems for residential use).
Ⅵ. For which types of systems is ZEREZ mandatory?
- Photovoltaic systems: Both private and commercial systems must be registered in ZEREZ.
- Wind turbines: Wind turbines are also subject to ZEREZ requirements.
- Battery storage systems: Energy storage systems also require registration.
- Combined Heat and Power (CHP) plants: CHPs and other conventional power generation systems must also be registered in ZEREZ.
- Other power plants: This includes hydroelectric and biogas plants, among others.