ᐅ Minimum Size of a Photovoltaic System for New Construction

Created on: 26 Sep 2023 10:32
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Ralf1980
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Ralf1980
26 Sep 2023 10:32
Hello.

For our planned house construction, I am wondering what the minimum size for a photovoltaic system is required.

Is there any regulation on what percentage of the roof area must be covered, or how many kWp need to be installed?

This question is explicitly about legal requirements, not economic feasibility.

Are there also legal requirements regarding whether a storage system is necessary?

The house will be heated with 100% sustainable district heating.

As an electrician, I will definitely install a photovoltaic system, but the question is whether there are any regulations I need to consider, or if I can do it as I please, and especially when I want to or can afford to.

Thank you very much.
Best regards, Ralf
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RotorMotor
26 Sep 2023 10:40
Unfortunately, there is not yet a nationwide requirement to install photovoltaic systems on new buildings. However, such regulations may exist at a regional level.
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WilderSueden
26 Sep 2023 11:11
Ralf1980 schrieb:

For our planned house construction, I am wondering what the required minimum size for photovoltaic systems is.
In Baden-Württemberg, it is 60% of the suitable roof area. You can find the exact calculation in the law or in the guideline for the photovoltaic requirement.
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KarstenausNRW
26 Sep 2023 11:41
No legal requirements according to KfW or QNG (at most indirectly, to meet the necessary values).

State regulations in BW/B/Hamburg; Bremen/Nds/NRW are currently under discussion or will apply from 2025.

Check with your state ;-)
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Ralf1980
26 Sep 2023 14:18
Hello.

I also found some information—at first, there were many search results about the appropriate size, etc.

From what I understand, the southern roof surfaces (with a deviation of up to 60 degrees east or west) are suitable areas, and they must be covered by 60% of the surface area.

Alternatively, 0.06 kWp per square meter of the built-up plot area

"The photovoltaic requirement is considered fulfilled if the photovoltaic system has a minimum installed capacity of 0.06 kilowatt peak per square meter of the built-up plot area."

"The built-up plot area includes the area where a building touches the ground with its outer walls, as well as any roof overhangs extending beyond that."

A 14 x 12.5 meter (46 x 41 feet) house and a 9.2 x 7 meter (30 x 23 feet) garage equals 239.4 m² (2,577 ft²) × 0.06 = 14.4 kWp

That’s quite a lot, more than I expected.