Study shows opportunities for façade greening and solar panels
A recent study by Lucerne University of Applied Sciences and Arts shows how facade greening and solar panels on buildings can be effectively combined to meet the challenges of global warming. The results offer valuable insights and practical recommendations for building owners and planners.
As part of the GreenPV project, a research team from Lucerne University of Applied Sciences and Arts has developed innovative solutions for the design of building façades. The aim was to explore the potential of photovoltaic systems (PV) and greenery in order to meet the increasing challenges posed by global warming. A brochure specially developed for planners and building owners summarises the findings and recommendations of the project.
The importance of this research becomes clear when you look at the forecasts of the National Centre for Climate Services: The average annual temperature in Switzerland could rise by up to 5.4 degrees by the end of the 21st century. This will not only significantly increase energy requirements, particularly for cooling, but will also affect comfort levels in buildings. Photovoltaic systems can supply energy precisely when it is needed most, namely when the sun is shining intensely. At the same time, green façades offer a sensible alternative in urban areas where new green spaces are scarce.
Façades as untapped potential
“While the benefits of PV systems and greenery are already increasingly being used on roofs, façades have so far remained largely unused,” explains Dr Silvia Domingo, researcher at HSLU. Yet façades offer an excellent opportunity for energy generation and greening without taking up additional space. PV systems on south-facing façades are particularly efficient in the cold season, as they can make optimum use of the low angle of inclination of the sun.
However, the study also shows that there are obstacles that stand in the way of a wider application of these technologies. These include financial challenges, a lack of guidelines and concerns about fire safety. These factors often cause uncertainty among building owners. To counteract this, the research team has produced a brochure with practical recommendations for the use of PV systems and greenery on façades.
Visual aspects and functional synergies
Another obstacle identified by Dr Domingo is the aesthetic perception of solar panels on building façades. Black solar panels often do not meet the visual expectations of building owners. However, research shows that solar panels in different colours and textures could also be available in the future without any significant loss of efficiency.
In addition to PV systems, green façades offer numerous advantages that go far beyond the cooling effect. They contribute to biodiversity, improve air quality, reduce sound propagation and promote rainwater retention. These benefits are particularly important in densely built-up urban areas, where they can significantly improve the quality of life.
The combination of greenery and PV systems
The HSLU study shows that greenery and PV systems on façades can often be combined well in order to utilise synergies. While PV systems on unshaded, higher façade areas ensure maximum energy generation, green areas near the ground have a cooling and noise-absorbing effect. This combination contributes to a more pleasant neighbourhood climate and climate-friendly electricity production.
Completion of the GreenPV project
The GreenPV project, which started in December 2021 and ran until mid-2024, was funded by a broad network of supporters, including the Swiss Federal Office of Energy (SFOE) and various foundations. The project team, led by Gianrico Settembrini, gained valuable insights, which are recorded in a brochure and are now available to planners, building owners and interested parties.
With the results of the GreenPV project, the HSLU is making an important contribution to sustainable development in the construction industry and demonstrating how greenery and solar panels on façades can be combined to effectively meet the challenges of climate change.