As the central register for the energy transition, the Market Master Data Register (MaStR) records data on all relevant market players in the electricity and gas energy market and, in a second step, all generation facilities:

• All new plants and all existing plants,
• Plants for the generation of renewable and conventional energy,
• plants for the generation of electricity and gas.

If you operate an electricity or gas generation system (e.g. photovoltaic system, wind energy system, combined heat and power plant, battery storage system, biomethane system), you must register it in the MaStR. You are also obliged to register if no subsidy is granted or claimed for the electricity from the system.
All running systems must be registered regardless of when they were commissioned - even if your system has been running for many years. This means that even if you have already registered your system at various other locations, for example with your grid operator or in previous registers of the Federal Network Agency, you must register these systems once again in the MaStR.
As a citizen (natural person), you can also register using forms on request in exceptional cases.
Authorities can access the data in the MaStR. This allows them to either significantly simplify their own surveys or dispense with them altogether. Installation operators and other market players can refer to the data they have entered in the MaStR.