At the end of 2025, the Canton of Aargau had around 757.8 megawatts of installed photovoltaic capacity across around 25,869 systems – ranking 12th out of 26 cantons in per capita density, above average for a large canton. Notifications run via the municipal council with a 30-day objection period; more generous size criteria apply in industrial, work, and commercial zones. (As of: SFOE register data August 2026, Swissolar annual figures 2025)
Key points in brief
- 757.8 MW installed capacity, around 25,869 systems (register status August 2026).
- Per capita around 1,019 watts per inhabitant – rank 12 out of 26, in the upper middle of Switzerland.
- Average system size: 29.3 kWp; in-roof proportion: 6.8% (below the Swiss average of 12.7%).
- Notification procedure: municipal council via energievollzug.ch/ag, 30-day objection period; industrial, work, and commercial zones are partially exempt from the otherwise applicable size limits.
How much photovoltaics is installed in the Canton of Aargau?
According to the SFOE installation register (as of August 2026), the Canton of Aargau has around 757.8 MW of installed capacity across around 25,869 systems. With around 1,019 watts per inhabitant, Aargau ranks 12th out of 26 cantons in per capita density – an above-average result for a populous canton.
| Metric | Value (Canton of Aargau) | Switzerland overall (comparison) |
|---|---|---|
| Installed capacity | 757.8 MW | 8,635 MW (register) / 9,498.6 MW (Swissolar) |
| Number of systems | 25’869 | 331,271 (register) / 338,270 (Swissolar) |
| Per-capita capacity | 1,019 W/inhabitant | 946 W/resident (Swiss average) |
| Per-capita density rank | 12 out of 26 | — |
| Average system size | 29.3 kWp | 26.1 kWp |
| Roof-integrated share | 6,8 % | 12,7 % |
Source: SFOE plant register (register status August 2026); national comparison values from Swissolar's «Solar energy statistics 2025».
What are the procedural rules in the Canton of Aargau?
Solar systems are reported to the municipal council in Aargau via the platform energievollzug.ch/ag (§ 49a BauV), with a 30-day objection period. A cantonal special feature: in industrial, work, and commercial zones, systems may be built exceeding the otherwise applicable federal size and distance criteria without requiring an ordinary building permit. Additionally, a separate notification to the Aargau building insurance (AGV) is intended. An important exception concerns objects in townscapes with the highest ISOS protection level (ISOS-A): there, the simplified notification procedure is not sufficient; the ordinary building permit procedure with cantonal review applies.
What does a real project from the canton show?
In Schneisingen (AG), ecoEn realised a 36.45 kWp system on an agricultural farm building in 2024, designed as a self-consumption community (ZEV) with private meter measurement, grid operator AEW. The project exemplifies what the above-average in-roof proportion contrast of the statistics looks like in practice: a classic on-roof solution on a large barn roof – the more common construction method in this region.
The low in-roof proportion in Aargau (6.8%) matches our experience: agricultural and commercial roofs, which make up a large part of the roof area in Aargau, are practically always realised as on-roof solutions – in-roof is rarely worthwhile there unless a roof renovation is already due.
Frequently asked questions
Why is the in-roof proportion so low in Aargau?
The statistics only show the frequency, not the cause. A plausible factor is the high proportion of agricultural and commercial roofs, on which on-roof solutions are usually the more obvious choice economically.
Does the same notice period apply everywhere in Aargau?
The 30-day objection period applies generally; however, certain otherwise applicable size criteria do not apply in industrial, work, and commercial zones. For objects in ISOS-A townscapes, on the other hand, the ordinary building permit procedure applies.
Is Aargau well advanced in terms of photovoltaics?
Measured by per capita density, Aargau is in the upper middle (rank 12 out of 26) – above average for such a populous canton.
How current are these figures?
Structural data as of August 2026 (SFOE register), national comparison values from Swissolar's 2025 annual statistics.
Agricultural or commercial roof in Aargau?
We realise solar systems in Aargau from the initial clarification to the ZEV implementation.
Sources: SFOE installation register (register status August 2026), Swissolar «Statistik Sonnenenergie 2025», cantonal leaflet Aargau (energievollzug.ch/ag), own project data.
Last updated: 18 September 2026 · Contact for questions on methodology: ecoEn editorial team
