Solar Obligation
Legal requirement to install a solar system on new buildings or during roof renovations -- in effect in several German states.
Also known as: PV Obligation, Solar Mandate, Solarpflicht
What Is the Solar Obligation?
The solar obligation legally requires builders to install a photovoltaic or solar thermal system on new buildings and, in some cases, during roof renovations. It is regulated at the state level and applies in several German federal states.
German States with Solar Obligation (as of 2024)
| State | Scope | Since |
|---|---|---|
| Baden-Wuerttemberg | New build (residential + commercial), roof renovation | 2022/2023 |
| Berlin | New build + roof renovation from 50 m² | 2023 |
| Hamburg | New build from 2023, roof renovation from 2025 | 2023 |
| Lower Saxony | Commercial new build | 2023 |
| Schleswig-Holstein | Commercial new build, car parks | 2023 |
| Bremen | New build | 2024 |
| Rhineland-Palatinate | Commercial new build, car parks | 2023 |
| NRW | Car parks | 2022 |
Typical Requirements
- Minimum size: 30—60% of the suitable roof area
- Alternative: Solar thermal instead of PV partially permitted
- Exemptions: Uneconomical, heritage protection, shading
- Verification: Within the building permit process
Practical Tip
Even without a solar obligation, a PV system is economically sensible for new builds. The costs can be integrated into the construction financing, and installation during the build is cheaper than a retrofit.
Related Terms
Photovoltaics
Technology for the direct conversion of sunlight into electrical power using solar cells made from semiconductor material.
EEG (Renewable Energy Sources Act)
German law promoting renewable energies -- governs the feed-in tariff for solar electricity, among other things.
Solar Thermal
Technology that uses solar heat for hot water preparation and space heating support via solar collectors.