Better planning of vertical PV systems thanks to technical manual

Photovoltaic modules on house roofs usually have an inclination that optimises the energy yield in summer. However, this means that the system produces less electricity in winter, although demand is then particularly high. This is where bifacial, vertically installed systems come into play. They can convert light into electricity on the front and rear sides and can be installed on open spaces or flat roofs. In alpine regions in particular, such systems produce significantly more electricity. Reason: electricity is generated not only by direct sun radiation, but also by diffuse irradiance, which is created, for example, by sun reflecting off snow. However, when planning such systems, it is often unclear what distances and orientations vertical modules should be installed at. This means that these values have to be calculated for each project by using complex simulations. The influence of local factors on the installation (e.g. snow, ground reflection or winter fog) is usually not known and must also be determined by using simulations or measurements on site. A guide drawn up by researchers at BFH’s Laboratory for Photovoltaic Systems aims to provide help in the design and dimensioning of bifacial, vertical PV systems in Switzerland, both on the Central Plateau and in the mountains.

The manual is now available (in German) and can be used in practice: