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The 1st TEC2ZERO Symposium informs about research activities and
serves as networking event for the new Activity Field “Technology Towards Zero Waste and Zero Carbon".
Members and partners of the University of Wuppertal whose research
is related to the new Activity Field "Technology Towards Zero Waste Zero
Carbon" are welcome. Please submit your abstract with a
maximum of 300 words (in English) using this homepage The
contributions to the symposium will be published in an open access
format. The Symposium is a BUW internal event, aiming at mutual information, initiating new cooperations and networking Participation is free of charge. Participants without own contribution are welcome to join.
9.10.2025, Vormittag
Probelms of Global Circular Economy linked to socio-ethical justice and challenges for science will be critically discussed from a global perspective.
Climate change presents unprecedented global challenges, urging a rethink of how resources, particularly energy, are harvested. Renewable energies like photovoltaics (PV) are probably the most sustainable energy sources, relying on the sun’s free energy. However, PV remains underutilized, especially in developing countries, where infrastructure costs and maintenance pose significant barriers. Additionally, fossil fuels remain often more affordable and flexible, exacerbated by the "green paradox" - as decarbonization progresses, the reduced demand for fossil fuels may cause their prices to fall.
To remain competitive, renewable energy technologies like solar cells must continue to become cheaper and more adaptable. Unfortunately, silicon solar cells have nearly reached their efficiency and production limits, which underscores the critical need for a next generation of solar cells.
At the Institute of Electronic Devices, we are devoted to developing advanced thin-film solar cell technologies using organic or perovskite materials, that we believe to provide an avenue of breaking the green paradox. Both technologies require minimal energy and can be processed using cost-effective printing techniques from abundant materials, whilst offering efficiencies competitive with silicon. As thin-film devices they can also readily be integrated into buildings, vehicles, and other applications like IoT and satellites, able to transform the landscape of solar energy.
For the vision of affordable solar power from perovskite or organic solar cells to become a reality, several roadblocks have to be overcome. Most prominently a solid understanding of the processing routes and an enhancement of the long-term device stability are challenges that we tackle in several projects spanning from fundamental to industry-oriented research. Here I will present recent breakthroughs in our chair with internal barriers and process design, that have led to significant improvements in both stability and efficiency, bringing us step by step closer to an actual industry viable perovskite-organic PV technology.
9.10.2025, Vormittag
The rare earth elements (REEs) are among the most crucial metals for high-tech and green energy applications and are considered critical raw materials. For example, neodymium (Nd) and dysprosium (Dy) are major constituents of wind turbines, with as much as several hundred kilograms in a single wind turbine magnet. The progress of high-tech applications and E-mobility will increase the global demand for REEs. However, the increasing usage will inevitably result in an elevated anthropogenic input of critical raw materials, such as REEs, into natural environments. Such emerging contaminants are already ubiquitous in river waters, seawater, and even tap water worldwide. Since many critical raw materials may harm living organisms when exposed to elevated concentration levels, monitoring these materials in Earth’s ecosystems will become a crucial task in the near future. This monitoring requires extensive data, some of which are already available through scientific publications and databases. Thus, there is a need for solutions that assist in the surveillance of large environmental datasets.
As part of the QuARUm project, we transferred the geochemical domain expertise on the natural behaviour of REEs into a data assessment method that automatically detects anthropogenic REE contaminations. In the future, we aim on continuing the work on developing low-code and easy-to-use data analytics that simplifies working with REE related samples. This line of work aims to improve the low-code language used in the data analytical process and increase the replicability of data processing by automating it.
Weißer Wasserstoff, also natürlich entstandener Wasserstoff, gewinnt zunehmend an Bedeutung als bislang unterschätzte und potenziell disruptive Energiequelle im globalen Energiemix. Er entsteht durch geochemische Prozesse wie Serpentinisierung tief in der Erdkruste und sammelt sich über geologische Zeiträume in unterirdischen Reservoiren an. Diese Form der natürlichen Wasserstofferzeugung kommt ohne CO₂-intensive Vorprozesse oder externen Energieeinsatz aus, was sie im Ver-gleich zu etablierten Verfahren besonders umweltfreundlich und kosteneffizient macht. Sie kommt einer standardisierten Gasförderung sehr nahe.
Aktuelle Pilotprojekte, etwa in Mali, Frankreich oder Albanien, belegen sowohl die technische Machbarkeit als auch die Reinheit und Nutzbarkeit der geförderten Ressourcen. Erste techno-ökonomische Analysen schätzen die Förderkosten auf nur etwa 0,5 bis 1 $ pro Kilogramm. Ein Wert, der deutlich unter dem von grünem Wasserstoff liegt. Letzterer wird derzeit, abhängig von Standort und Energiepreisen, mit etwa 2 bis 7 € pro Kilogramm veranschlagt. Auch der ökologische Fußabdruck ist gering. Mit rund 0,4 CO₂/kg zählt weißer Wasserstoff zu den emissionsärmeren Formen verfügbarer Wasserstoffenergie. Dies ist hinsichtlich des weltweit weiter an-steigenden Energiebedarfes von äußerster Bedeutung.
Die globale Ressourcenschätzung liegt im zweistelligen Teratonnenbereich. Studien eines amerikanischen Forscherteams, aus dem Jahr 2024, haben errechnet, dass sich potenziell bis zu 6,2 Billionen Tonnen weißen Wasserstoffs in der Erde befinden können. Selbst eine teilweise Nutzung würde ausreichen, um den weltweiten Energiebedarf über viele Jahrzehnte zu decken. Somit könnte er eine tragende Rolle bei der Dekarbonisierung von Industrie, Mobilität und Stromerzeugung einnehmen. Trotz dieser Potenziale bestehen noch Herausforderungen bei der Erkundung, Erschließung, rechtlichen Regulierung, Sicherheit usw.. Gleichzeitig wächst das internationale Interesse rapide mit Beteiligung großer Energieunternehmen und staatlicher Explorationsprogramme. Langfristig könnte sich natürlicher Wasserstoff zu einer Schlüsselressource der globalen Energiewende entwickeln; ökologisch,
gesellschaftlich, wirtschaftlich und geopolitisch.
Polymers are important for humanity from daily life usage to advanced science and technology. Considering the degradation rate of polymers in nature and associated difficulties in recycling monomers by depolymerization, the widespread polymer usage poses a significant environmental hazard generating waste in a linear economy. Thereupon, the widespread use of self-immolative polymers, macromolecules can undergo simultaneous depolymerization with trigger activation, for such applications could be a potential solution to these drawbacks. In this study, our plan is to design mechanochemically active self-immolative polymers for functional materials production. Methodologically, carbamoyloxime scaffolds, have been developed by our research group, applied as mechanophore to trigger two different self-immolation approaches. The first approach is directly triggering the self-immolation of 4-aminobenzylalcohol-based poly-carbamates by the activation of aniline units. On the other hand, the second approach uses an indirect trigger, including base-promoted depolymerization of poly(butyl cyanoacrylate) via mechanochemical activation of organic superbases. By combining the mechanochemical approach with self-immolative polymers, it is aimed to achieve more selective self-immolation and complete depolymerization of polymers following mechanochemical activation. This selective self-immolation potentially render polymers a more sustainable alternative for several fields from material science to biotechnology.
eingeständiges Mittagessen, z.B. Mensa
9.10.2025, Nachmittag
The urgent need to replace fossil-based resources with sustainable alternatives calls for innovative strategies in biomass valorization. Among these, the efficient use of lignocellulosic biomass has proven particularly promising. Although a complete substitution of fossil fuels is unlikely, biomass can serve as a viable and renewable feedstock for a significant fraction of chemical production. To avoid conflicts with food supply, research efforts must focus on second-generation (2G) biomass sources—such as agricultural residues, food processing by-products, and invasive plant species.
Electrochemical lignin depolymerization has emerged as a powerful approach for the production of valuable chemical intermediates. Historically, bulk electrodes composed of carbon, nickel, lead, platinum, or copper have been used, but their limited structural tunability restricts both reactivity and selectivity. Overcoming these limitations requires a transition to nanostructured systems. Nanoparticle-based electrodes have already shown improved catalytic performance, while further advances can be achieved using single-atom (SACs) or dual-atom catalysts (DACs), in which nearly every metal atom contributes as an active site, enabling close to 100% atomic efficiency.
These catalysts rely on stable support materials, with carbon-based matrices being widely applied. To enhance the overall sustainability of the system, carbon supports derived from waste biomass—such as spent coffee grounds, brewers' spent grains, or invasive plants like Japanese knotweed—have been successfully implemented. Iron, nickel, and copper nanoparticles or atoms dispersed on such supports have proven effective in reductive electrochemical lignin depolymerization. Catalyst structures and dynamics have been characterized using XRD, XPS, SEM-EDX, LEIS, TEM, and in-operando XAS. The time resolution of modern synchrotron-based spectroscopy enables the investigation of structural and electronic transformations on millisecond to hour timescales, providing insight into the behavior of catalysts under reaction conditions.
The resulting depolymerization products offer synthetic potential and support the development of a more sustainable, circular chemical economy.
This study explores the upcycling of grinding swarf, a by-product of subtractive machining, into semi-finished cast products by recovering silicon carbide (SiC) and aluminum oxide (Al₂O₃) abrasives and using them as alloying additions. Two cold-work tool steels, X153CrMoV12 (1.2379) and 80CrV2 (1.2235), were modified, with emphasis on X153CrMoV12 due to its higher content of critical alloying elements. The recycling route comprised the thermal removal of coolant residues, particle separation by sieving and magnetic purification, and direct alloying of the residual abrasives during casting. Al₂O₃ floated into the slag while SiC fully dissolved, raising the melt’s carbon content from 1.53 mass% to 1.78–2.51 mass% and its silicon content from 0.35 mass% to 0.94–1.73 mass%. Using up to 31.0 mass% recyclates met the X153CrMoV12-1 standard; relaxing the silicon target to ~1.0, mass% allowed the incorporation of up to 68.0 mass% recyclates. Thermodynamic simulations predicted a similar solidification sequence and microstructure in recycled and reference alloys. Microstructural investigations of the cast samples by SEM and the methods adapted to it (EBSD) revealed an austenitic as-cast matrix with blocky M₇C₃, MC, and M₂₃C₆ carbides. After quenching, comparable hardness levels were achieved between the three steel grades (800 HV1 vs. 806 HV1 vs. 800 HV10). Upon tempering at 500 °C, hardness differences became apparent (618 HV1 vs. 664 HV1 vs. 726 HV10). Microscopically, all materials exhibited a microstructure consisting of a metal matrix of tempered martensite with a high-volume fraction of carbides.
Hypervalent iodine reagents offer powerful oxidative capabilities and have emerged as attractive, metal-free alternatives to traditional oxidation methods that often rely on toxic metals. However, their high-energy character can raise significant safety concerns, especially in traditional batch processes. In response to these challenges, we have developed a series of continuous flow methodologies that enable safer, cleaner, and more efficient oxidative transformations.
By leveraging solid-supported iodine(V) reagents, green solvents, and benign co-oxidants, our work demonstrates how flow chemistry can unlock the full potential of hypervalent iodine reagents while minimizing environmental impact and operational risk. Our continuous flow system demonstrates excellent robustness, maintaining full efficiency over at least 15 consecutive runs without significant catalyst leaching or degradation.
These systems consistently deliver high selectivity, improved reaction control, and scalability—without compromising safety or sustainability.
Multi-criteria decision-making for product selection in construction is becoming increasingly important, as purely technical and economic evaluations can no longer capture the complex demands of sustainability. In particular, ecological and socio-cultural criteria exert a decisive influence on the life-cycle assessment (LCA) of building materials and are embedded in certification systems such as DGNB and LEED, as well as in the EU Taxonomy and various ecolabels. Against this backdrop, an ontology-based decision-support system leveraging GraphRAG is under development. It systematically extracts relevant information from unstructured sources—technical data sheets, safety data sheets, and Environmental Product Declarations (EPDs)—represents this information within a knowledge graph, and makes it interactively queryable in combination with large language models (LLMs).
By integrating semantic ontology with AI-driven language processing, GraphRAG enables automated responses to complex, multi-hop queries: planners, contractors, and sustainability auditors receive context-aware recommendations that interlink technical performance, cost efficiency, and both ecological and socio-cultural dimensions. For example, the system can identify low-emission insulation materials that not only satisfy energy-performance requirements but are also manufactured under socially responsible production conditions. To validate the system, structured expert interviews were conducted with stakeholders from architecture, site management, and certification bodies. These interviews captured typical information needs and decision workflows, from which a set of “must-have” queries was derived—queries that GraphRAG must answer reliably and transparently. Particular emphasis was placed on performance under multi-query scenarios, such as the concurrent evaluation of life-cycle costs, carbon dioxide (CO₂) equivalents, and health-relevant emissions.
Evaluation results demonstrate that GraphRAG provides significant time savings and enhanced transparency in the decision-making process compared with conventional research methods. In the long term, this approach promises to systematically promote more sustainable construction products and to streamline the practices of product selection and certification.
10.10.2025, Vormittag
When communicating on climate goals, the underlying models of change are rather complex and not always intuitive. My poster addresses this problem in the transdisciplinary frame of narratology and history of ideas, by highlighting Twentieth-Century traditions of storytelling and alternative conceptualisations of epochal change. Typical zero narratives of the past are event-centred. This holds true for the military and political “zero hour” as well as for fictional variations such as in Agatha Christie’s Towards Zero (1944), where the story converges towards the vanishing point of the crime. The post WW2-years used a zero narrative to describe a total reset and loss of cultural baselines, either in fiction films such as Rossellini’s Germania anno zero, or anthropological essays such as Morin’s L’an zero de l’Allemagne. I argue that such event-centred narratives are hardly adequate to describe climate change and politics; this inadequacy shows in the difficulty of pinpointing the “Anthropocene” to a specific date and the subsequent divergences on this issue. However, Twentieth Century history of ideas also offers an alternative mindset, which is that of the threshold narrative. The philosopher Hans Blumenberg criticizes the tendency to identify “zero points” in history. Against the zero narratives, he defends the idea of an asymptotic limit, an invisible threshold between epochs. In Aspekte der Epochenschwelle (1976), he suggests that changes in history do not occur on specific dates or turning points. One can only notice that a threshold has been crossed, not where this threshold lies precisely. No single events are sufficient to indicate profound changes such that between one epoch and another. Blumenberg’s concept can not only lead to a new understanding of story analysis in narratology, but also provides a more adequate model for communicating climate goals such as that of a development “towards zero carbon and zero waste”.
The current challenges of societal transformation into socially fair and ecologically sustainable economies require a deeper understanding of how people can be motivated, supported and empowered to change their habits and engage in sustainable behavior over longer time periods. In the present paper, we elaborate on the Personality-System-Interaction Theory as an integrative theoretical framework in psychological research, which differentially explains how, when, and why people are able and willing to support sustainable transformation and engage in environmentally compatible behavior. On the basis of this framework, we provide insights into three current projects, which aim at facilitating ecologically sustainable processes by creating best-possible psychological preconditions. First, the project “bergisch.kompetenz” seeks to develop and transfer in-depth expertise of solutions of circular economy into companies via human-resource processes (e.g., personnel and organizational development). In this project, we conceptualize different methods and instruments (based on the Personality-System-Interaction Theory), which enable and empower employees and experts to create and monitor sustainable material circles across different companies. Second, we also demonstrate another transdisciplinary project “Fit4Klima”, which aims at developing and distributing a web- and APP-based software that fosters a sustainable and healthy behavioral lifestyle in different private domains (e.g., nutrition, sport activities, vacation, mobility etc.). Third, we will show and discuss findings from a longitudinal study on the relationships between individual attitudes, motivational tendencies, perceived political initiatives of sustainable transformation and sustainable behavior (foot-print). In doing so, we provide insights into promising precursors of sustainable behavior under different psychologically and politically relevant boundary conditions.
The transition to low-carbon energy systems has fostered the development of market-based instruments, such as CO₂ emission allowances (EAs) and renewable energy certificates (RECs), to reduce greenhouse gas emissions and incentivize renewable energy production. This project explores the mathematical modeling, analysis, and numerical solution of these instruments, contributing both theoretical and computational advances.
EAs are central to cap-and-trade systems, where firms trade allowances under a regulatory cap on emissions. Their price dynamics depend on multiple uncertain factors-in particular, electricity demand and cumulative emissions-and are modeled using forward-backward stochastic differential equations (FBSDEs) and related nonlinear partial differential equations (PDEs). We aim to extend existing models by incorporating feedback mechanisms and jump processes, leading to more complex semilinear partial integro-differential equations (PIDEs). Rigorous mathematical analysis ensures the well-posedness of these models, while novel numerical schemes improve computational efficiency.
A less mature but growing area of study is RECs, which are issued to renewable energy producers. Here, the certificate price depends on stochastic renewable generation and certificate accumulation. The project investigates FBSDE formulations where the existence of solutions remains an open question due to full coupling. We extend the modeling of REC dynamics and analyze the pricing of both standard (European) and advanced (American, exotic) derivatives using PDEs, complementarity problems, and expectation-based formulations. Efficient solution techniques, including finite difference, semi-Lagrangian, and Monte Carlo methods, are developed and tested.
This interdisciplinary work bridges applied mathematics, finance, and energy economics, providing valuable insights into sustainable energy market design and risk management. The models and methods developed have broad applicability in quantitative finance, policy modeling, and computational science.
In this paper we paper suggest a systemic approach to strengthen sustainable literacy through strategic design on a societal level. The UN Resource Council (2020) underscores that extending product life cycles and increasing the intensity of use is crucial for meeting climate and resource goals. Design can help to bind carbon dioxide in products and infrastructures in the long term and on a large scale—make it available for further use (Carbon Cycle). Extending product life cycles requires not only a cultural shift in production but also in consumption habits, supported by repair-friendly products and accessible services.
Against this background, we present the project Sustainable Design Literacy, launched within the Master's Program in Strategic Innovation in Products and Services. Placing repair at the heart of the circular economy, the project aims to build competencies across the entire life cycle—from design and production to use, maintenance, repair, and responsible disposal. A multi-stage roadmap to 2030 outlines three core goals: raising awareness, strengthening knowledge and skills, and creating repair opportunities.
The project specifically targets the needs of 18- to 34-year-olds because they have a significantly lower awareness of repair compared to older groups (Micklitz et al., 2022). Key elements of the concept are: legal and education-oriented measures (e.g., repair escape rooms); concepts for manufacturing companies (e.g., forms of interaction such as digital twins and repair apps); strategies for service providers (e.g., platforms and repair services); and product design (e.g., “readable” and modular products, modular designs). The concept highlights that transformation towards more sustainable forms of production and consumption need new and diverse educational formats, intelligent products and innovative business models, but also supportive policy frameworks.
To conclude, we will use the visual outputs from the project to discuss the role of design in enhancing communication among diverse stakeholders to reach sustainable literacy together.
10.10.2025, Nachmittag
The increasing complexity of energy system models necessitates the use of surrogate models for efficient computation of optimal operations. In recent years, physics-based surrogate modeling has gained significant attention for its ability to enhance the accuracy of these surrogate models. However, applying surrogate modeling to complex networks introduces the challenge of system decomposition.
When reassembling the system after surrogate models have been identified, the resulting interconnected model may lose critical system-theoretic properties such as stability or passivity.
We utilize the port-Hamiltonian (pH) framework, which facilitates physics-based modeling and maintains structural interconnections. The pH approach is demonstrated in the context of sector-coupled energy systems, where the pH modeling approach is demonstrated for electricity, heat, and gas grids. We show how submodels of the components such as transmission pipes, storages or heat pumps can be identified from high-fidelity simulation data. These identified pH models are then integrated into a comprehensive pH system model, facilitating optimization of the overall operation of the system. Finally, we present a comparative analysis of the optimization outcomes for both the surrogate model and the high-fidelity model, evaluating their performance in terms of accuracy and computational efficiency.
Ongoing climate change is accompanied by an increase in the frequency and severity of extreme weather events, including heavy rainfall, extreme heatwaves and cold spells [1, 2]. These events represent climatic hazards that can significantly affect electrical distribution systems, potentially leading to power outages [3]. To achieve maximum energy efficiency in the electrical distribution system, a resilient power supply system is essential. This requires the identification of vulnerable equipment and the evaluation of appropriate countermeasures.
Beyond analyzing the general climatological frequency of such events, this contribution focuses on region-specific conditions that influence their local impact. For this purpose, publicly available datasets - including digital elevation models, building structures, and road networks - are used to examine prevailing environmental parameters. These parameters inform a vulnerability assessment by linking hazard exposure with site-specific factors affecting the resilience of the electrical distribution system.
Extreme heatwaves and high temperatures can cause individual equipment to fail or degrade, particularly in secondary systems such as control and protection devices. These hazards are exacerbated by the urban heat island phenomenon, where densely built and sealed city centres exhibit significantly higher temperatures than surrounding rural areas [4]. Accordingly, influencing factors such as building density, surface sealing, and vegetation type are central to evaluating heat-related impacts.
In contrast, the same factors can mitigate rapid temperature drops during cold spells by retaining heat. However, additional hazards such as snow and ice must also be considered. In this context, other influencing factors - including slope inclination, slope orientation, and regional altitude - become increasingly relevant.
The presented analysis enables the identification of vulnerable equipment and supports the evaluation of locally adapted mitigation strategies to improve the resilience and hence the efficiency of electrical distribution systems. The methodology is applied to the supply area of a German distribution network operator.
While building performance simulation (BPS) is becoming increasingly vital for sustainable building design, in alignment with the net zero carbon by 2050 target, under growing climate and regulatory pressures, its pedagogical integration faces challenges such as students’ limited knowledge in building physic and overreliance on simulation outputs, therefore difficulty in understanding abstract simulation models.
This study focuses on the integrated adoption of building performance assessment methods, such as BPS, monitoring, testing, and measurements in order to create teaching materials to promote building performance learning in architectural and engineering education. The research is structured on the thesis that providing real performance data obtained from existing buildings as a reference point in simulation studies can reduce the level of abstractness of BPS and thus increase the effectiveness of the building performance learning experience.
The Living Lab NRW, hosted by the University of Wuppertal, serves as a research, education, and public knowledge center for a sustainable built environment. It consists of eight solar-powered experimental houses designed and constructed during the Solar Decathlon Europe 21/22. Utilizing these houses as case studies, the development of teaching materials is structured in five phases:
(I) Planning and setting up monitoring systems, measurements, and tests,
(II) Collection of real performance data,
(III) Creation and calibration of BPS models using the data,
(IV) Processing data into educational materials, and
(V) Use of it in building performance teaching.
This paper presents results from the first three phases, focusing on energy and daylighting models of selected Living Lab houses. Two main assessments are highlighted: thermal and daylight performance comparisons via measurements, tests, calculations, and simulations.
This study not only contributes to the development of educational materials on building performance but also shares experiences from the data collection and processing phases, offering key insights and practical recommendations for educators in building science.