As the central register for the energy transition, the Market Master Data Register (MaStR) records data on all generation plants: All new plants and all existing plants, installations for the generation of renewable and conventional energy, electricity and gas generation plants. If you operate an electricity or gas generation plant (for example, photovoltaic plant, wind energy plant, combined heat and power plant, battery storage, biomethane plant), 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 plant. All running plants must be registered regardless of when they were commissioned - even if your plant has been running for many years. This means that even if you have already registered your plant in various other places, for example with your grid operator or in earlier registers of the Federal Network Agency, you must register these plants again in the MaStR. If an installation is shut down, you must also report this in the register. If the installation is not connected to any electricity or gas grid, no notification is required. To ensure that payments under the Renewable Energy Sources Act (EEG) or the Combined Heat and Power Act (KWKG) are paid out without deductions, you must comply with the registration deadlines set by the legislator. You must register via the Federal Network Agency's Internet portal. As a citizen, you can also register via forms in exceptional cases. Authorities can access the MaStR data. This enables them to either significantly simplify their own surveys or dispense with them altogether. Plant operators and other market players can refer to the data they have entered in the MaStR.