immo!nvest – Die Plattform für Standorte und Immobilien

Tag: Gebäudefassaden

  • Study shows opportunities for façade greening and solar panels

    Study shows opportunities for façade greening and solar panels

    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.

  • “NEST provides the ideal environment to further develop our innovation”

    “NEST provides the ideal environment to further develop our innovation”

    Buildings are responsible for more than 40 per cent of global energy consumption. A large part of this is used to ensure user comfort – i.e. for heating and cooling. Especially in view of the current developments in the energy market, the big question is how we can cover our energy consumption in the future. Ways must be found to tap new energy sources and at the same time reduce the energy consumption of buildings. One of these could be the better use of façade surfaces.

    This certainly holds potential, since the majority of the building façade is still unused and at the same time the central factor for either letting energy into the building or keeping it inside. Researchers at ETH Zurich have therefore developed an innovation as part of the NEST HiLo unit that can exploit this potential: an adaptive solar façade that not only optimises electricity production, but also reduces energy loss at the same time. Attached to the actual façade, this forms a kind of second skin for the building. The innovation thus also bears the appropriate name “Solskin”.

    Simple architectural embedding
    “We wanted to develop a façade that could be very easily installed on a building and optimally integrated into the architecture,” Bratislav Svetozarevic explains the idea behind the innovation. He was significantly involved in the development of “Solskin” from the beginning, first in 2014 as a PhD student in Arno Schlüter’s “Architecture and Building Systems” group at ETH Zurich and from 2018 as a Post Doc at ETH and Empa, where he researched related topics.

    “Solskin” consists of a lightweight substructure that is attached to the façade. Mounted on it are small square thin-film solar panels that can be colour-matched to the existing building envelope. In this way, the solar façade blends in perfectly with the overall appearance of the building. At the same time, the panels can be turned individually in all directions. This is because behind each module there is a control unit that Svetozarevic and his colleagues have developed over the years. The special thing about it is that the panels are aligned using air pressure. The materials used are both robust and flexible so that the system can withstand strong gusts of wind and precipitation.

    Reality check
    The idea behind the flexible alignment is that the solar façade can follow the position of the sun, thereby optimising electricity production. At the same time, “Solskin” also serves to actively shade the building in summer, thus reducing the need for cooling, or to open the panels and let the sun’s rays into the interior, thus saving heating energy in winter.

    The first prototype tests at ETH Zurich have convinced the researchers of the innovation’s applicability. But would the innovative façade also work on a real building? To find the answer to this question, “Solskin” was attached to the façade of the HiLo unit. “HiLo offered us the opportunity to install and test our system on a busy building for the first time. This enabled us to record the usage and acceptance of the users,” explains Svetozarevic. An important factor, because in addition to the actual system, the researchers also developed an algorithm that records the needs of the people working in the HiLo unit and can thus improve user comfort in addition to optimising production. This is now being further developed with the help of data from operation at NEST.

    A bright future
    The results of the prototypes and the pilot project at NEST point in a clear direction: energy can be saved with “Solskin” – and saved enormously. While solar production can be increased by up to 40 per cent compared to conventional solutions, savings of up to 80 per cent are possible in heating and cooling energy compared to a conventional, non-adaptable shading system. “We are pleased that we were able to show at NEST that our system works and what potential it has,” says Svetozarevic, beaming. Various expert juries were also convinced of this potential and awarded “Solksin”. Among the awards is the renowned Watt d’Or, which is awarded annually by the Federal Office of Energy.

    The next step is now commercialisation. To this end, Bratislav Svetozarevic and his team founded the spin-off “Zurich Soft Robotics” in 2022 and have already landed a major contract. The company KELLER Druckmesstechnik AG in Winterthur wants to attach “Solskin” to its new production building – on a total area of 1,300m2.

    In addition to its use on new buildings, however, the innovation is also ideal for upgrading older buildings. Solskin” thus has great potential to optimise the energy efficiency of the entire building stock and thus provide an answer to the question of how we can continue to generate enough energy to operate our buildings in the future.