immo!nvest – Die Plattform für Standorte und Immobilien

Tag: EPFL

  • EPFL researchers improve efficiency of solar cells with rubidium

    EPFL researchers improve efficiency of solar cells with rubidium

    Researchers at EPFL have discovered a method for reducing the energy loss of perovskite solar cells, according to a press release. Perovskite solar cells are based on semiconductors with a wide bandgap, but they often suffer from phase separation, which causes a drop in performance over time. The integration of rubidium (Rb) is intended to stabilise the semiconductor material and at the same time improve the energy efficiency of the solar cell. By utilising the lattice voltage of the perovskite film, the researchers were also able to ensure that the Rb ions are fixed in the right place.

    The researchers led by Lukas Pfeifer and Likai Zheng from Michael Grätzel’s group at EPFL also used the X-ray diffraction method to verify and analyse this effect. They discovered that, in addition to the lattice stress, the introduction of chloride ions also makes a decisive contribution to the stabilisation of the material. The chloride ions equalise the size differences between the incorporated elements and thus ensure a more uniform ion distribution. The result is a more uniform material with fewer defects and a more stable electronic structure.

    The new perovskite composition reached 93.5 per cent of its theoretical limit with an open circuit voltage of 1.30 volts. This is one of the lowest energy losses ever measured in perovskite semiconductors. An improved photoluminescence quantum yield also indicates a more efficient conversion of sunlight into electricity.

    Increasing the efficiency of perovskite solar cells could lead to more efficient and cost-effective solar modules and thus reduce dependence on fossil fuels. Perovskites could also be used for LEDs, sensors and other optoelectronic applications. The EPFL’s findings could therefore also accelerate the commercialisation of these technologies.

  • EPFL develops concept for city-river balance on the Rhône

    EPFL develops concept for city-river balance on the Rhône

    The redevelopment of brownfield sites along the Rhône should balance the needs and constraints of a city and its river. Based on this guideline, a group of architects from the Laboratory for Architecture and Sustainable Technologies at the EPFL has developed a corresponding handbook for those with political responsibility.

    According to a press release, the group selected two locations in Switzerland, Sion VS and Geneva, and two in France, Givors and Avignon, for their study. For each district, they developed three customised and architecturally different visions. In total, the team identified more than 1400 neighbourhoods in transition along the Rhône. It sees enormous potential in this for the development of derelict areas that were abandoned by companies, for example, when they abandoned the waterways.

    The study did not look at urban areas as a whole, as is usually the case. “Our approach is different because we tackle urban development and planning issues on a smaller scale and focus on individual river neighbourhoods,” lab and study leader Emmanuel Rey is quoted as saying. “Our tool provides a more detailed, entirely local picture of what the river can do and how it interacts with the city,” Rey says. “In that sense, it’s an argument against traditional, generic planning.”

    This new assessment method with its 18 indicators was applied as an example to one of the case studies, the La Jonction neighbourhood in Geneva. For example, the indicator for the energy transition shows whether a particular vision is in line with the canton’s overall strategy. At the city level, it can be used to evaluate plans for shuttles, pedestrian bridges or other aspects of river transport. And at the neighbourhood level, for example, it provides information on whether river water could be used to heat or cool buildings.

  • EPFL student turns plastic waste into bricks for building

    EPFL student turns plastic waste into bricks for building

    For her master’s thesis in civil engineering, Selina Heiniger developed a method for the more sustainable production of building material. According to a press release from the Swiss Federal Institute of Technology in Lausanne ( EPFL ), she uses plastic waste, concrete that has already been used and terracotta bricks that have been made small.

    In her master’s thesis, Heiniger wanted to tackle two related challenges: reducing environmental pollution from plastic waste and developing construction methods that use fewer raw materials.

    She developed bricks made from recycled plastic – polypropylene (PP), polyvinyl chloride (PVC) and high-density polyethylene (HDPE) – as well as crushed terracotta bricks and recycled concrete. Their bricks are designed to interlock, so no mortar is required. Initial tests are encouraging, but the invention is still in the prototype stage. If successful, Heiniger’s work could make a significant contribution to reducing the construction industry’s carbon footprint.

    Heiniger graduated from high school in the canton of Bern and then enrolled at the EPFL to study civil engineering. At first she only studied part-time, as she also worked in a civil engineering company in Lausanne.

    Selina Heiniger’s master’s thesis was jointly developed by Corentin Fivet, head of EPFL’s Laboratory for Structural Exploration in the Faculty of Architecture, Civil and Environmental Engineering, and Yves Leterrier, a senior scientist at EPFL’s Laboratory for Advanced Composites Processing in the Faculty of engineering, supervised.

  • Individually air-conditioned offices increase well-being

    Individually air-conditioned offices increase well-being

    People feel differently comfortable under the same temperature conditions. This has now been confirmed by measurements by researchers at the Swiss Federal Institute of Technology in Lausanne ( EPFL ) in a normal office environment. They collected thermophysiological data from test subjects. According to a statement by the EPFL, they show that age and gender influence metabolism. And this in turn can vary depending on diet, season and daily rhythm.

    Air conditioners are currently designed for space, not people, explains Dolaana Khovalyg, assistant professor at EPFL’s Faculty of Architecture, Civil and Environmental Engineering and head of the Integrated Comfort Engineering Laboratory . 80 percent of employees feel comfortable with an average office temperature of 21 degrees in winter, but 20 percent do not. “Our goal is to make everyone feel good, without exception.”

    The ability to accurately measure a person’s energy use paves the way for a new breed of technology that feeds the collected data into central heating and cooling systems. These in turn can adjust the temperature in a specific area, such as a desk, in real time, thereby optimizing energy consumption in buildings.

    Now the research team is looking for less invasive measurement methods than the silicone face masks and body sensors that the subjects had to wear. It currently works with infrared cameras. Questions of data protection are still to be clarified. Their study was recently published in the Obesity Journal.

  • New development to reduce railway noise

    New development to reduce railway noise

    Researchers from the Swiss Federal Laboratories for Materials Testing and Research ( Empa ), the University of Economics and Engineering of the Canton of Vaud and the Swiss Federal Institute of Technology in Lausanne ( EPFL ) have jointly developed new rail pads. These components are mostly made of elastic plastic and are stuck between rails and concrete sleepers, as Empa explains in a press release . They are used to protect rails.

    However, existing rail pads have limitations. Especially if the protection of the rails is greatly increased, this leads to more noise pollution at the same time. The researchers now want to solve this challenge. After several tests in the laboratory, a part with more than 50 percent polyisobutylene (PIB) content, embedded in a shell made of a harder ethylene vinyl acetate (EVA) plastic, proved to be the most effective option. At the same time, it can reduce railway noise and protect the rails.

    In a next step, the new rail pads are to be tested on a railway line in Nottwil in March. “These rail pads are easy to make. We will need almost 400 units for the 100-metre stretch,” explains Bart van Damme from Empa’s Acoustics and Noise Reduction department. That is why a company is already on board that will take over the manufacture of the components that have already been patented.

  • EPFL exhibits Design Brain in Seoul

    EPFL exhibits Design Brain in Seoul

    The Media x Design Laboratory of the Swiss Federal Institute of Technology in Lausanne ( EPFL ) is currently exhibiting a larger-than-life design brain in the South Korean capital. The exhibit called Artificial Swissness can be seen until October 31 at the Seoul Biennale for Architecture and Urbanism .

    According to a communication from EPFL, Artificial Swissness aims to extend the epistemology of computer science to the cultural field. “Our design brain is an experiment on the question of whether machines can design structures,” laboratory director Professor Jeffrey Huang is quoted as saying. “That means whether they can not only recommend music or drive cars, but also create meaningful cultural artefacts, such as architecture with distinctive Swiss characteristics.”

    As the message goes on to say, the exhibit should be a constantly changing spatial interface that represents the inner thoughts of an artificial intelligence machine that has been trained on 10,000 images of Swiss chalets and alpine architecture. “We make the visual interferences in these layers of the neural network visible,” say the two EPFL students Frederick Kim and Mikhael Johanes. “This gives us an insight into the inner workings of our generative artificial network that creates architectural images.” The two of them set up the installation in Seoul after a 14-day quarantine.

    The digital screens of the installation show the machine-generated images of typical Swiss architecture. At the same time, an LED projection reveals the constantly evolving learning process that the machines go through while they sift through thousands of images of alpine architecture in order to distill the essence of “Swissness”.

  • Switzerland has great potential for geothermal energy

    Switzerland has great potential for geothermal energy

    Switzerland has considerable potential in the use of alternative energy sources such as geothermal energy and in the underground storage of CO2. This emerges from a press release from the Swiss Federal Institute of Technology in Lausanne ( EPFL ). Professor Lyesse Laloui from the Faculty of Architecture, Civil and Environmental Engineering ( ENAC ) at EPFL was head of the research group on geoenergy as part of the Innosuisse Energy funding program, which ran from 2013 to 2020. Eight competence centers have been set up. EPFL played a leading role in the field of geoenergy. Laloui is the author of the chapter on this in the final report of Innosuisse.

    Lyesse Laloui sees great potential for the use of geothermal energy. The Swiss government has set the target for 2035 of generating 11 percent of the energy used for heating and cooling buildings from geothermal energy. Laloui assumes over 20 percent. “The project results show that this share could easily be doubled,” he is quoted in the communication. The possibilities of using geothermal energy to generate electricity were also examined. Laloui points out problems such as drilling deep without triggering seismic movements. “One day we will surely make it, but we are not there yet.”

    According to the Lalouis report, there are good opportunities for the underground storage of CO2 emissions in Switzerland, especially in the Central Plateau from Friborg to Zurich. Professor Laloui is quoted as saying that of the around 40 million tonnes of CO2 equivalent that are emitted in Switzerland every year, around 12 million could be stored underground.

  • Enerdrape wins with climate panels for buildings

    Enerdrape wins with climate panels for buildings

    Enerdrape has 150, 000 francs under the support of Venture Kick obtained as from a message stating. The spin-off from the Swiss Federal Institute of Technology in Lausanne ( EPFL ) is developing a sustainable solution for air conditioning in buildings. The start-up's system consists of modular panels that are installed indoors. These use the existing thermal energy and waste heat to heat and cool the building.

    According to Enerdrape, heating and cooling buildings alone are responsible for around 40 percent of CO2 emissions in Europe. According to the start-up, sustainable alternatives often require a complex installation process and are also expensive. In contrast, the solution from Enerdrape is cheap and easy to implement. The company's panels are particularly intended for installation in underground garages and commercial buildings. In Europe, Enerdrape sees a potential market of CHF 40 million here.

    The Venture Kick funding initiative supports young companies from the idea to the establishment of a company. The Venture Kick Foundation mandated the institute for young companies , which is represented in Schlieren ZH, St.Gallen and Lausanne, to carry out the initiative.

  • Artificial intelligence recognizes the type of land use

    Artificial intelligence recognizes the type of land use

    Thanks to a student at the Swiss Federal Institute of Technology in Lausanne ( EPFL ), the regularly necessary classification of land use is now much less time-consuming than before. According to a press release from the university, she has developed and trained her own machine learning algorithm that can not only distinguish forests from other types of land. Instead, Valérie Zermatten's algorithm also recognizes rivers, lakes, camping and sports fields, cemeteries, water treatment stations, public parks, airports and dams. This makes it clearly superior to the algorithm developed by the Federal Statistical Office (FSO) called Areal Statistics Deep Learning, or ADELE for short.

    The results produced by their program as part of a master’s thesis are similar to the official data published by the FSO. According to the announcement, this suggests that it could be used for land use classification in the future. The big advantage lies in the processing time for aerial photos, because their classification into around 40 different categories is still largely done by hand.

    All of Switzerland is photographed from the air every three years. Because manual categorization takes so long, the results are only published every six years. With this mapping, land consumption can be better tracked, soil permeability can be monitored and urban sprawl can be combated.

    “Our goal is not to replace humans with artificial intelligence,” says Devis Tuia, one of Zermatt's doctoral supervisors at EPFL. “Although Valérie's algorithm will reduce the amount of tedious work that has to be done manually.” But even then there is still enough for people to do – for example, to recognize whether it is a house or a school, a football field or a football field Wiese act.

  • Sika supports the introduction of Swiss eco-cement

    Sika supports the introduction of Swiss eco-cement

    LC3 stands for Limestone Calcined Clay Cement and was developed by the Swiss Federal Institute of Technology in Lausanne ( EPFL ). It is a sustainable cement product that has a clinker content that is up to 50 percent lower than that of traditional cement. Clinker makes a significant contribution to CO2 emissions during cement production. In LC3, a large proportion of clinker is replaced with a new additive, which means that overall less CO2 is emitted in cement production.

    The Zug-based construction chemicals group Sika wants to support the market launch of LC3, as he writes in a press release. He wants to develop and offer special cement additives and concrete admixtures that help customers adapt their materials to the properties of LC3. This should enable the water consumption, workability, hardening and durability of the LC3 concrete to remain the same compared to conventional products. According to its own statements, Sika is also ready for “comprehensive product tests with interested customers”.

    "With these new LC3 products, we are putting the goals of our sustainability strategy into practice," said Frank Höfflin, Sika's head of technology, in the press release. “Our aim is to act as an enabler for sustainability in the construction industry and to develop more environmentally friendly and more efficient products,” he emphasizes.