Solar potential for the roofs of Swiss buildings
soolar maps the solar potential of roofs across Switzerland, based on the federal BFE Sonnendach dataset. Every roof on the map is shaded by its solar suitability, so good roofs stand out before you click. Search an address or click a building, and soolar reads the roof data for that spot.
What you see for each building
- Annual PV yield (kWh per year)
- Suitable roof area (m²)
- Mean irradiation (kWh/m² per year), weighted by roof area
- Estimated revenue (CHF per year)
- Monthly production chart and the number of roof surfaces analyzed
- Suitability class, from low to excellent
When several buildings lie near the point you click, each gets its own card, identified by its EGID where available.
How to read the numbers
Yields and roof irradiation are modelled values from Sonnendach, not measurements. They are theoretical maxima: real output depends on shading, system efficiency and the orientation you choose for the panels.
What else you can do
- Fade the solar overlay and switch between light, dark and satellite basemaps
- View buildings in 2D or 3D
- Compare locations and track parcels in your account
- Export the result as a PDF report, JSON, CSV or GeoJSON
- Share a link or QR code that reopens the same roof
Frequently asked questions
How much solar power can this roof produce?
Click the building and soolar shows its annual PV yield in kWh per year, summed over its analyzed roof surfaces, with a month-by-month chart. The figure is a modelled estimate from BFE Sonnendach and a theoretical maximum; actual production depends on shading, system efficiency and orientation. For a binding figure, ask a solar installer for a quote.
Where does the solar data come from?
From the BFE Sonnendach roof suitability dataset of the Swiss Federal Office of Energy, served by swisstopo through the geo.admin.ch API.
What does the suitability class mean?
Each roof falls into one of five classes, from low to excellent, based on its modelled annual irradiation. The legend runs from under 800 to over 1400 kWh/m² per year.