PV system size The 10 and 30 kW limits

PV system size: The 10 and 30 kW limits

For private owners of a photovoltaic system, an output of 10 kW was a magical limit for a long time for various reasons. Although the roof size is appropriate for a PV system of this size in many cases, there have been some legal or regulatory reasons for limiting the solar system’s output in this way. However, the 10 kW limit has not been a hard limit for a long time. The new annual tax law now eliminates the last reason for a PV system with a size of less than 10 kW. The new magic limit is now 30 kW. In this article, we will explain what you should pay attention to regarding the size of your PV system.

How big can a PV system be?

The size of your future solar panels system is first limited by one factor – your available roof area. And yet there are two sizes you should consider when planning your future PV system: 10-kilowatt peak and 30-kilowatt peak. Because these represent certain limit values for rules relating to feed-in tariffs, taxation, and the registration of your PV system, in this article, we explain which limits you should keep in mind about which factors.

10 and 30 kW limits for feed-in tariffs

Let’s first look at the feed-in tariff – because different regulations apply here for PV systems of different sizes. On July 30, 2022, the new version of the Renewable Energy Sources Act (EEG) came into force as part of the Easter package. As part of this, the remuneration for electricity fed into the public grid was increased. The following feed-in tariffs were decided:

For PV systems up to and including 10 kW: 8.2 cents per kW. For each additional kW up to and including 40 kW: 7.1 cents per kW

The EEG remuneration is calculated pro rata. Each PV system – whether larger or smaller than 10 kW – receives a feed-in tariff of 8.2 cents for the first 10 kW of the solar system and 7.1 cents for the next 30 kW. So if you run a 20 kW system, you get 8.2 cents for 50 percent of your fed-in electricity and 7.1 cents for the other 50 percent.

Conclusion: There is no reason to remain below a size of 10 kW for feed-in tariffs. Larger private off grid solar systems are also profitable.

How big can a solar system be without registration?

As a solar system operator, you must register them with the Federal Network Agency. Only then will you receive the feed-in tariff for your unused solar power.

You can only operate a solar system without registration if it is a stand-alone system. This means your PV system is not connected to the power grid, and you only use the generated electricity. If you operate an island system without registration, there is no limit in size.

However, operating a stand-alone solar system is only worthwhile in rare cases. You can find out more about this in our blog article “PV off-grid system – the solution for a power failure”?

Tax liability for 10 and 30-kW systems

Until 2022

From June 2, 2021, the 10 kW limit applied to the tax liability of photovoltaic systems. Smaller systems with an output of up to 10 kW were no longer subject to the obligation to submit an income surplus calculation as part of the income tax return. This meant that systems of this size were no longer subject to income tax considerations and were considered a hobby. It was assumed that PV systems of this size were not installed to make a profit.

The limit of 10 kW is always applied to the total of all mini solar panels of the taxable person, even if they are located separately on several properties. Anyone who owned several solar systems with a total output of more than 10 kW could not be exempted from income tax liability.

Other requirements were:

In addition to being fed into the grid, the electricity is only used in your living space. No partial use of the electricity by tenants or for operational purposes (except for work rooms for dependent work)

PV system size The 10 and 30 kW limitse

From 2023

With the new annual tax law’s entry into force, this will look different in the future. Because from January 1, 2023, the income tax for PV systems up to a size of a 30-kilowatt peak will be completely abolished. Thus, the so-called 10 kW limit in the taxation of PV systems up to 30 kW is eliminated.

EEG surcharge and the former 10 kW limit

By the end of 2020, operators of a PV system with an output of more than 10 kW had to pay 40 percent of the EEG surcharge for the electricity they used. This means that the price of solar power has increased by 2.7 cents per kW for solar system owners (40 percent of the EEG surcharge of 6.75 cents in 2020).

With the changes in the EEG, which came into force at the beginning of 2021, this limit of 10 kW is no longer applied. It has been increased to an output of 30 kW or 30 MWh per year.

However, with all PV systems with an output of less than 30 kW, there were no additional costs for using the electricity from your own solar system. This also applied to PV systems installed before January 1, 2021. The profitability of self-consumption of electricity from the PV system has thus increased.

Since July 1, 2022, consumers no longer have to pay the EEG surcharge for PV systems of any size because this will be completely abolished with the EEG 2023 to relieve consumers more.

Is there a maximum size for private PV systems?

In principle, there is no limit to the dimensioning of private PV systems. So, the bigger, the better? This is not true for the size of private solar power systems. Because a solar system always works most profitably when it is planned according to needs and adjusted to the consumption of the household. Your solar system is always most profitable when using most of the electricity you generate. Oversizing is only worthwhile if you plan to purchase more consumers shortly. This could be e-cars or a heat pump, for example.

So there is no generally applicable limit for the maximum size of private PV systems. As a rule, however, the size of these is limited by the available roof area. If you are unsure about the dimensioning of your future solar system, our specialist advisors will be happy to help you anytime.

10 and 30 kW limits for PV systems for rent

People interested in PV are increasingly opting to rent a solar system on their roofs. But do the limits for feed-in tariffs and taxation described above also apply here?

In terms of the feed-in tariff, it makes no difference whether you rent or buy a solar system. In both cases, you receive a payment of 8.2 cents per kW of electricity for your PV system up to and including 10 kW that you feed into the public grid.

Regarding taxation, the rental of PV systems differs from the purchase – this has been the case since the new annual tax law was passed. Because the rental model is not yet considered in the tax exemption1 for solar systems up to 30 kW.

How big are 10 and 30-kW PV systems?

You have learned much about the different 10 and 30-kW regulations. But how big are PV systems of this size? The average solar system size sold at solar is around 9.2 kW – this can serve as a rough guide in advance.

From this, you can already see that solar systems with a total output of 30 kW are already very large in the field of private solar systems. The largest package we offer is therefore currently with an output of 21 kW. In this table, we give you an initial overview of the number of solar modules and the required roof area for solar systems of this size.

Would you like to find out more about the optimal size of your future solar solution? Then look at our blog article “Calculate the size and performance of your PV system.” With the help of our solar calculator, you will already get an initial orientation concerning the size and performance of your future PV system.

PV systems size The 10 and 30 kW limits

How much do 10 and 30-kW PV systems cost?

In addition to the existing roof area, the price of your future solar system also plays a decisive role. We have summarized the prices of the two sizes in the following table. The prices already include 0 percent VAT since solar systems of this size also benefit from the changes in the context of the new annual tax law.

However, the exact cost of your future solar system should always be determined based on your needs, ideas, and wishes. Our specialist consultants are always at your side when planning your solar solution and will give you important tips about your PV project.


When planning your future solar system, the choice of output and size plays a decisive role in its subsequent profitability. However, it would help if you keep certain guidelines regarding feed-in tariffs and taxation in mind.

For PV systems up to and including 10 kW, you receive a feed-in tariff of 8.2 cents per kW. If you are planning a solar system up to and including 40 kW, the feed-in tariff is 7.1 cents per kW of electricity you supply to the public power grid. With the passing of the new annual tax law, the 10 kW limit for the taxation of PV systems no longer applies. If you buy a PV system up to a size of 30 kW today, you can benefit from the tax exemption.1 This means that sales and income tax will no longer be an issue in the future. Increasing the feed-in tariff and simplifying the taxation of PV systems will make the switch to renewable energy in the private sector increasingly appealing. While there are certain benchmarks you can use to guide you about the above factors, your solar installation should always be planned based on your needs and your vision.






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