Is the roof of my house suitable for a solar plant?
You can find the answer in just a few clicks at sonnendach.ch. The interactive website shows how suitable a property is for the production of solar energy. Building data from swisstopo forms the basis for calculating solar potential.
According to the Swiss National Energy Strategy 2050, the use of domestic and renewable energies should be increased. The use of solar energy is therefore an important pillar of future energy supply. Solar energy hits the Earth's surface in the form of light and heat and can be used in various ways: for example, by photovoltaic (PV) systems to generate electricity or by solar panels to generate heat. The potential of solar energy in Switzerland is considerable. According to the Swiss Confederation’s energy strategy, around 20 percent of the current electricity demand can be generated by photovoltaics and around 10 percent of the heat demand by solar thermal energy by 2050.
On the sonnendach.ch website, the solar energy potential of roofs and facades can be easily determined, as well as the costs for the necessary infrastructure. You can therefore ask it whether your own house roof is suitable for solar energy use and how much electricity and heat could be produced. The platform serves, on the one hand, as a source of information for private individuals, and on the other hand, as a data basis for further evaluations and planning, for example in potential studies by cantons and municipalities or for electricity grid planning.
Joint project
The Swiss Federal Office of Energy SFOE developed the solar cadastre in collaboration with the Federal Office of Topography, swisstopo and the Federal Office of Meteorology and Climatology, MeteoSwiss. The application links data from swisstopo on the size and orientation of individual roof surfaces with climate data (solar radiation and temperature) from MeteoSwiss. The SFOE is leading the project and is responsible for the user interface.
swisstopo data
As an important partner, swisstopo provides its three-dimensional building data for the calculation of solar potential and makes the resulting data available as a service via the federal geodata infrastructure, FSDI.
The 3D information on buildings is derived from the swisstopo dataset, swissBUILDINGS3D 2.0. This is a vector dataset which represents buildings as 3D models with roof shapes and roof overhangs. The dataset is used in a variety of ways, for example for 3D printing, noise propagation analyses, visibility and shadow casting analyses or even for the solar cadastre. The 3D geometries of the roof surfaces in swissBUILDINGS3D 2.0 are reduced to two dimensions for sonnendach.ch and displayed as 2D polygon geometries (roof surfaces). For the shading analysis – the calculation of possible shadows at different times of the day or year in the photovoltaic system – the swissALTI3D elevation model and the digital surface model DSM from swisstopo are used in addition to the building geometries from swissBUILDINGS3D 2.0.
The company Meteotest compiled the data for sonnendach.ch. The calculations it carried out include a whole range of information for each individual roof surface, from solar radiation and photovoltaic production to heating degree days and the number of showers possible with a solar thermal system on a roof surface.
Results
When you locate your property on sonnendach.ch, the application classifies the roof area into five categories: low, medium, good, very good and excellent, and shows how much solar power could be produced per year and its monetary value. The solar cadastre calculates many more values: the potential of solar heat, inclination, orientation and area of the roof, possible electricity production over the last twelve months and the remuneration tariffs for feeding into the electricity grid.
Additional information
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