Market master data register: What you need to know about solar systems and the like
What is the Market Master Data Register?
The Market Master Data Register (MaStR) is a comprehensive official register for all electricity-generating plants. It has been online since the beginning of 2019 and replaces all previous reporting channels for plants under the Renewable Energy Sources Act (EEG) or the Combined Heat and Power Act (KWKG).
All grid-connected power generation plants and battery storage systems must be registered in the MaStR. The register is to list all more than three million decentralised plants in operation in Germany.
What is the purpose of the Market Master Data Register?
The market master data register is intended to bundle a wealth of information on the electricity market in a large database and make it available to the public. This is intended to simplify and abolish reporting obligations – but initially brings additional effort and additional bureaucratic hurdles. Precise knowledge of the locations and sizes of the plants is also required for the expansion planning of the power grids.
Who has to register in the market master data register?
For example, if you generate electricity privately with a solar system that is connected to the grid, you must enter it in the market master data register of the Federal Network Agency. This applies to all photovoltaic systems, combined heat and power plants (CHP), battery storage systems, CHP plants, wind turbines and emergency power generators. All operating systems must be registered regardless of the time they are commissioned – even if your system has been running for many years.
Are the previous entries at the Federal Network Agency not sufficient?
No – even if you have already registered your system in various other places, for example with your grid operator or the Federal Network Agency in the old plant register, the following still applies: You must also enter these systems again in the new market master data register. It completely replaces the former PV reporting portal of the Federal Network Agency.
Your data that has already been reported elsewhere will not be taken over due to the General Data Protection Regulation (GDPR). You will definitely need to register again!
What happens if I don't register my investment in the register by the deadline?
There is a reporting obligation for the market master data register. If you do not register your system on time, there is a risk of losing your remuneration under the EEG or KWKG and a fine. Financing banks or funding agencies often require proof of registration as proof that the system has been built and put into operation.
You have not registered your system in the market master data register? In this case, you are not entitled to remuneration under the EEG or KWKG.
Furthermore, the regulatory authority can impose a fine under the EnWG (§95).
What is the deadline for an existing system?
Do you have a system that is already running, e.g. a solar system or a CHP plant, that was in operation before 31 January 2019? Then you had until the end of January 2021 to enter this attachment in the register. If you have not already done so, you should do so immediately. As long as the registration has not been made, the network operator is not allowed to pay you the remuneration.
What is the deadline for a new plant?
Every new plant must be entered in the market master data register within one month of commissioning. This applies to all systems that have been launched from February 2019. You can also register your planned system before commissioning. If the registration is not made within the deadline, the grid operator may withhold payment of the feed-in tariff until the registration has been completed and proof is submitted.
What does the simplified registration mean for plug-in solar devices?
Plug-in solar devices, like large photovoltaic systems, must also be entered in the market master data register. To this end, the Federal Network Agency has put a simplified input mask online on April 1, 2024, in which only a few technical details of the plug-in solar device have to be entered. Prior to this, the user of the register must register once and confirm the name and address of the operator of the plug-in solar device. In the third step, the number of modules, the power and the commissioning date of the plug-in solar device are entered.
I have a battery storage system – do I have to register it additionally?
Yes, you have to register each electricity-generating system individually. This also includes a battery storage system. If you operate a photovoltaic system with battery storage, you must enter both the solar system and the battery storage system individually in the register. If the photovoltaic system consists of several parts that were put into operation at different times (years or months), these must also be entered separately.
What is the deadline for battery storage systems?
You also had to register existing battery storage systems by 31 January 2021 to avoid cuts in EEG subsidy payments. The one-month deadline also applies to new storage systems.
What data do I have to enter in the register?
Only the so-called "master data" is requested in the register: location data, technical plant data and your contact details. Data about your yield or the like does not have to be entered.
Depending on the type of system, different amounts of data are requested. Find out in advance about all the data required for registration via the registration aid of the Federal Network Agency. There you will also find video instructions that guide you step by step through the entries. You can also add some information after a successful registration.
Do I have to keep the data up to date?
Yes, you are obliged to keep the data of your system up to date.
This can be the case, for example, if you enlarge your photovoltaic system or have it converted from full feed-in to self-supply. This must also be reported when an electricity storage system is subsequently installed.
And finally, you must also delete your photovoltaic system from the market master data register if you have the solar modules from your roof finally dismantled and disposed of.
Where can I find further information?
The Federal Network Agency offers an overview of frequently asked questions about the market master data register. It can also be reached Monday to Friday from 9 a.m. to 5 p.m. via the hotline 0228 14-3333. You can also send inquiries electronically via the contact form here.
This content was created by the consumer advice centres of North Rhine-Westphalia and Rhineland-Palatinate for the network of consumer advice centres in Germany.