How to Register Solar System: Essential Guide for Compliance

How to Register Solar System: Essential Guide for Compliance

Investing in a solar system is one of the best ways to cut down your energy bill and contribute to a greener planet. However, the transition to solar energy is not as simple as installing panels on your roof. You need to register solar system with authorities to comply with legal frameworks.

In this guide, we delve into the intricacies of solar system registration, delineates the steps involved across different regulatory bodies, list the required data and deadlines to keep in mind, and clarify the consequences of overlooking this crucial process. Read on to learn all the insights you need!

Why Must Solar Systems Be Registered

First and foremost, registration is a legal requirement. The German Renewable Energy Sources Act (EEG) stipulates that all solar power systems must be registered to legally feed electricity into the national grid. This registration is crucial for system owners to qualify for financial incentives such as feed-in tariffs or market premiums, which significantly reduce the payback period of the initial investment in solar technology.

Moreover, registering a solar system helps ensure the stability and efficiency of the energy grid. By knowing the location, size, and capacity of all solar installations, grid operators can manage the flow of renewable energy more effectively. Accurate data on solar installations allow for better planning and adjustments to the grid infrastructure, minimizing the risk of overloads or energy wastage.

Registration Requirements for Solar Energy Systems

Understanding the registration requirements is essential for any solar system owner or prospective buyer. Here, we outlined the necessary agencies and steps involved in the registration process, ensuring compliance and enabling access to financial incentives:

Register Solar System with the Federal Network Agency

The first step of the process is to go to Federal Network Agency to register solar system. This is completed online through the Market Master Data Register (MaStR) website, the central and official database designed for all electricity-generating systems in Germany.

As of 2024, the only instance where a PV system can operate without registration in the MaStR is an island system dedicated exclusively to self-consumption without any grid connection. Conversely, the moment a PV system, regardless of its size, is connected to the public grid, registration becomes imperative. This means you still need to register solar system for own consumption with a small-scale balcony power plant.

Private households are required to submit detailed information about their PV system, including the system type, its capacity, and location, no later than one month following the system's commissioning. If you decide to enhance your solar setup with a battery storage system, such as a balcony power plant with storage, it's essential to register this battery addition separately, right alongside your initial PV system registration.

Recognizing the potential complexity of these procedures, MaStR has developed digital registration assistants. These tools are designed to simplify the process, guiding you through each step with ease. For added convenience, private system owners have the option to delegate this task to an authorized representative, such as a professional from the installation company.

Upon successful registration, you will receive a confirmation along with a unique identification number. This identifier not only facilitates smoother communication among energy suppliers and network operators, but also plays a critical role in the administration of feed-in tariffs and the billing of electricity.

Register Solar System with Network Operator

In addition to registering with the Federal Network Agency, you must also inform your local network operator about your solar energy system. This entity, which could be your local municipal utilities, is tasked with the technical integration of your PV system into the power grid, managing the absorption of any excess solar energy you produce, and facilitating the payment of feed-in tariffs.

Identifying the responsible network operator is straightforward and can be done by reviewing your annual electricity bill. Instead of a direct name, you might find a 13-digit code. This code serves as a key to uncover your network operator either through the MaStR database or via the BDEW platform.

In most cases, the process of notifying the network operator and ensuring compatibility is managed by the installation company you hire. This includes a review to verify that the solar system meets all necessary technical requirements for grid connection—a process that could extend over several weeks. Depending on the outcome, there might be a need for technical modifications to guarantee the safe injection of generated electricity into the grid.

H3: Register Solar System with Tax Office

Operating a solar system that feeds electricity back into the public grid is considered a business activity under German law, as the income generated from feed-in tariffs may be subject to taxation.

However, to encourage the adoption of solar energy, recent regulations have introduced exemptions to simplify the process for smaller-scale installations. As of 2023, operators of private PV systems with an output of less than 30 kWp for single-family homes and less than 15 kWp per residential unit for multi-family homes, are exempt from the trade and income tax, which also means that there is no requirement for these smaller systems to register with the tax office. Therefore, if you want to adopt a system like the Anker SOLIX Balcony Power Plant with an 800Wp output, you don't need to register at the tax office.

For larger PV systems with an output of 30 kWp or more, or those in apartment buildings with an allocation of 15 kWp per residential unit, registration is mandatory. Owners of these systems must register with their local tax office within four weeks of commencing operation.

Common Data for Registering Solar Systems

Whether you are registering with the Federal Network Agency, the tax office, or your local electricity network operator, you will need to provide specific information about your solar installation. Here's a breakdown of the common data required for registering solar systems across these entities:

General data:


  • Owner's Contact Information:Full name, address, telephone number, and email address.
  • Installation Address:Exact location of the solar installation, including specific sections if applicable.
  • Commissioning Date:The date your system officially started operating.

Technical Specifications of the Solar System:


  • Solar Panels:Make, model, and number of panels.
  • Inverters:Make, model, and capacity.
  • Power Storage Device:Make, model, capacity, if your setup includes a battery solution like the Anker SOLIX Balcony Power Plant with Storage.
  • System's Total Capacity:Overall peak output in kilowatts peak (kWp).

What Is the Deadline to Register a Solar System?

To help you navigate the registration process for your solar system, below is a table summarizing the critical deadlines for each registration requirement:




Federal Network Agency

Market Master Data Register

Within 30 days of commissioning

Local Network Operator

Commissioning protocol and confirmation from the Federal Network Agency

Within 30 days of commissioning

Tax Office

Required for systems over 30 kWp or 15 kWp per unit in apartment buildings.

Within four weeks of system commissioning

Consequences of Non-registration of Solar Systems

Non-registration of your PV system in Germany carries significant financial and legal consequences that affect your ability to operate sustainably and profitably:

  • Loss of Feed-in Tariff: Registration with the Federal Network Agency is mandatory to qualify for the feed-in tariff under the Renewable Energy Sources Act. Without registration, the network operator will not pay this crucial financial incentive.
  • Legal Penalties:Failing to register can result in fines as outlined in Section 95 of the Energy Industry Act (EnWG), emphasizing the legal importance of compliance.
  • Subsidy Repercussions:If you've received subsidies for your PV system, proof of registration is necessary. Non-compliance could lead to the withdrawal of these financial supports.


Navigating through the process of registering a solar system might seem daunting at first, but it is an indispensable step towards a sustainable and legally compliant use of solar energy. From understanding the why and how to register solar system to grasping the essential data needed for registration, we have covered the critical facets of making your solar system fully operational and recognized. The deadline for registration is a crucial date that cannot be missed if you want to avoid the consequences of non-registration, which range from legal repercussions to financial losses. As we embrace solar power, let us also embrace the responsibilities that come with it, ensuring our journey towards renewable energy is as smooth and compliant as possible.


Can I register a photovoltaic system myself?

Yes, you can register a photovoltaic (PV) system yourself in Germany. The process involves registering your system with the Federal Network Agency via the Market Master Data Register website and inform your local grid operator to confirm that your system complies with relevant technical standards. Additionally, you might need to register with the Tax Office to manage taxes on income generated from feed-in tariffs.

How many kW are tax-free?

Based on the German Renewable Energy Sources Act (EEG) 2023, operators of private photovoltaic (PV) systems installed on private single-family homes with a nominal output of up to 30 kWp, as well as 15 kWp per residential unit for multi-family homes are exempt from sales and income tax.

Is the battery storage tax exempt?

From 2023 onwards, battery storage systems integrated into private photovoltaic (PV) systems on single-family homes, featuring a nominal output of up to 30 kWp, as well as those in multi-family homes with up to 15 kWp per residential unit, are exempt from sales tax. This exemption applies regardless of whether they are acquired alongside the PV system initially or are installed subsequently as a retrofit.