MINI POWER · MASTR-HELP 2026

Register your balcony power plant & storage

Choose your battery, inverter, or balcony power plant kit. You will receive a ZIP file containing the available original manufacturer documents: datasheets, certificates, and other registration documents. This includes a registration guide in PDF format and a PDF listing any missing documents and how to obtain them. You then enter your registration data directly into the official MaStR (Market Master Data Register).

Create my document package View process
  • Package function · 27.09.2026
  • No personal information required
  • No password prompt

SHORT ANSWER

A balcony power plant must be entered into the market master data register. A stationary battery storage system, directly or indirectly connected to the public grid, is additionally registered as a separate unit. When combining PV and storage, you generally need two sets of data – even if both functions are integrated into a single device. A one-month deadline applies to each unit, starting from its actual commissioning.

1 · CORRECTLY CLASSIFY

What needs to be registered?

"Balcony storage" is not a uniform registration category. What matters is which units are actually operated and how they are connected to the public electricity grid.

Balcony power plant without storage

The solar unit is registered in the MaStR (Market Master Data Register). For simplified plug-in solar registration, the following limits apply, among others: a maximum module power of 2.000 W and a maximum inverter power of 800 VA.

Balcony power plant with storage

PV and storage are two register units. They can be recorded in the same wizard run, but afterwards both must exist as separate units.

Upgrade storage

If the PV system is already registered, the new stationary grid storage system will be added and linked to the existing solar unit. Please have its MaStR number ready.

Mobile Power Station

A device primarily used for mobile purposes such as camping or outdoor activities is typically not a stationary power storage device. However, the product name and "zero feed-in" alone do not determine whether it is legally required.

Important for all-in-one devices

A shared housing does not automatically result in a single registration entry for the PV system and battery. After completion, check whether both the solar unit and the storage unit have been registered.

STORAGE FINDER & COMPARISON


Check the 800 VA rating clearly before selecting the product.


The comparison separates the confirmed 800 VA/plug-in solar proof from higher grid and separate emergency power output.

  • 9 short questions
  • 800 VA separately
  • Price per kWh
Compare 800 VA status Free · about 2 minutes

2 · PREPARE

What should you have ready?

The documents primarily serve to ensure accurate readings. For small systems, "having them ready" does not automatically mean that every document must be uploaded.

Person and location

  • Access to your email address for the MaStR account
  • Data from the actual plant operator
  • Residential and alternative installation address
  • Electricity bill including meter number and network operator

Facilities and Dates

  • Commissioning date of the PV unit
  • Separate commissioning date of the storage system
  • Existing MaStR numbers
  • Information on feed-in tariffs

Technical documentation

  • Nameplates of modules, inverters and storage systems
  • Data sheets and operating instructions
  • Invoice and, if applicable, commissioning report
  • Certificates or network operator documents, if required
The purchase date is not the commissioning date.

For a balcony power plant, the decisive factor is when alternating current first entered the apartment's electrical circuit – often the first time it was plugged in. For a storage system, the relevant date is its own technical commissioning. If you are unsure of the date, check your records instead of estimating.

3 · REGISTER

Step-by-step through registration

  1. 01

    Clarify scope and operator

    Specify whether the PV system, the storage system, or both units will be newly registered. The operator is the person who actually controls the operation and bears the economic risk – not necessarily the owner or the invoice recipient.

  2. 02

    Create a MaStR user account

    Register in the official market master data register and confirm your email address. Use your own password, known only to you.

  3. 03

    Plant operators record

    Enter your name, address, and contact details. If the plant location differs, provide both addresses separately.

  4. 04

    Register solar unit

    For a suitable plug-in solar device, select the simplified procedure. Enter the commissioning information, location, module power, inverter power, and meter number using your documentation.

  5. 05

    Add storage unit

    Register the storage system as a separate unit. Depending on the interface, information such as technology, connection type, usable capacity, power output, grid operator, and the linked solar unit will be requested.

  6. 06

    Review the network operator process

    The simplified plug-in solar system "MaStR only" does not automatically apply to storage systems. Please check the portal and the technical connection requirements of your grid operator.

  7. 07

    Download confirmations

    Check all the information. Save the registration confirmation for each created unit and note the respective MaStR numbers.

Open official MaStR

4 · CHECK TWO WAYS

MaStR and network operators are not the same thing

MARKET MASTER DATA REGISTER

Nationwide Register

PV systems and stationary grid storage are recorded there as separate units. Registration does not always replace further technical notifications.

NETWORK OPERATOR

Local connection process

For storage systems, compensation requests, or installations outside the simplified plug-in solar rules, the local process must also be reviewed. Portals and additional fields vary regionally.

If a storage system can be charged from the public grid and the grid connection capacity for electricity withdrawal exceeds 4,2 kW, the process for controllable loads according to Section 14a of the German Energy Industry Act (EnWG) may also become relevant. The commissioning date, grandfathering rights, and the actual storage system configuration must be checked in this regard.

5 · SELECT PRODUCT & LOAD DOCUMENTS

Your registration document package

Select your battery, inverter, or balcony power plant kit and, if applicable, the appropriate variant. We will bundle the manufacturer's original PDFs and two registration guides into a ZIP file. You will then enter your personal information and system specifications in the official register.

Locally in the browserNo customer account or personal data required
  1. 1Select products
  2. 2Download package
Which products are part of your investment?

Search for the exact product name. Selecting the correct product does not confirm an order and does not replace verifying the product against the invoice, variant, and nameplate.

Select at least one product to receive your document package.

Your choice decides

Select the variant on your invoice and compare it to the model delivered. The documentation for a set may cover several versions. Information on the correct version and the actual contents of the package can be found inside.

6 · SECURE BOUNDARY

Why we don't ask for your MaStR password

Mini Power never asks for your MaStR password. The official MaStR guidelines require that regular login credentials be kept confidential. You enter your personal data and asset values ​​directly into the official MaStR.

The document package provides the manufacturer's documentation and instructions for the next steps. Open the official register, follow the field guides, and download your registration confirmation there upon completion.

7 · CHECK

Official sources

Editorially reviewed on August 20, 2026. Registration forms, legal regulations, and network operator processes are subject to change. The most up-to-date information provided by the authorities and your network operator is authoritative. This page does not replace legal, tax, or electrical engineering advice.