This project is intended to help researchers design a new lab for digital fabrication at the Institute of Structural Concrete using a circular economy concept. By using existing resources responsibly and reducing CO2 emissions, the lab’s construction is to become a flagship project for RWTH and its future construction plans. The lab shall be used to research automated and serial construction using digital production methods (e.g., 3D concrete printing), making it predestined for exemplary implementation. It is well-known that concrete production is responsible for up to eight percent of anthropogenic CO2 emissions. In addition to this high carbon footprint, the consumption of aggregates (sand, gravel) in concrete production is also immense. Combining the latest research results with modern manufacturing methods will open up many opportunities to save resources in construction. As part of the project, a local source of recycled aggregate will be produced by demolishing existing storage buildings on the construction site following the urban mining concept. The new building will then be constructed using so-called R-concrete, which has a significantly higher proportion of recycled material than is currently typical. This will allow the institute to benefit from all the positive properties of solid construction in a sustainable manner, such as high storage mass and thus lower cooling needs, as well as resilience, convertibility, and load-bearing capacity.

Contact: Christian Dommes, M.Sc., Chair and Institute of Structural Concrete

In addition to technical and process-related efficiency and saving measures, people’s habits also have a major influence on resource consumption, for example, by how they ventilate rooms for fresh air or whether they conscientiously switch off electronic devices that are not in use. The main objective of this resource-monitoring project is to change consumers’ habits by offering them the technology to capture indoor climate and consumption data, allowing them to achieve energy savings first of all but to also possibly lead to a positive physiological and psychological effect, for example, through feedback and gamification (Méndez et al. ii, 2022; Valor et al. ii, 2019; Zangheri et al. ii, 2019). However, few systems on the market now allow flexible integration of individual consumer equipment (e.g., office devices) independent of manufacturer and device and permit flexible feedback messages or gamification enhancements. The “Ressourcen-Wächter Technische Hochschule” proposed here is based on the chair’s own sensor technology and measuring systems developments, allowing for flexible and modular system design. Building, person, and activity-related specifics can thus be better integrated and optimized in terms of consumption and emissions. Part of this project is to expand on an existing measurement and feedback system that is based on Qirui Huang’s master’s thesis and to subsequently field test it in an RWTH building with 20 to 25 participants. During the field test, the testers are asked to evaluate the system’s feedback and energy savings tips (ventilation behavior, thermostat settings, switching off electrical appliances). To validate these subjective assessments, researchers will also use consumption data for the relevant building (part of the building) for evaluation, if available. Instead of smartphones or similar devices, a desktop app will be integrated into the employees’ stationary work computers and interactive touch screens will be provided for devices.

Sources:
Méndez, J. I., Peffer, T., Ponce, P., Meier, A., & Molina, A. (2022). Empowering saving energy at home through serious games on thermostat interfaces. Energy and Buildings, 263, 112026.
Valor, C., Escudero, C., Labajo, V., & Cossent, R. (2019). Effective design of domestic energy efficiency displays: A proposed architecture based on empirical evidence. Renewable and Sustainable Energy Reviews, 114, 109301;
Zangheri, P., Serrenho, T., & Bertoldi, P. (2019). Energy savings from feedback systems: A meta-studies’ review. Energies, 12(19), 3788.

Contact: Dr. Marc Syndicus Institute of Energy Efficiency and Sustainable Building

Poorly maintained and historically grown compressed-air systems can leak and lead to considerable energy loss. Therefore, identifying and eliminating leaks is always the first step in optimizing compressed-air systems because it is easy to do and very effective. The significant rise in energy costs in the recent past has already increased industry’s awareness of this potential. However, interest in these savings has been relatively low compared to the measures already implemented at RWTH. The project aims to remedy this situation by raising awareness among users and operators, enabling them to identify leaks independently and providing them with the data they need to discuss investment decisions.
The Gas and Microsystems Junior Research Group at the Institute for Fluid Power Drives and Systems (IFAS) plans to carry out a study on an internal 14-bar compressed-air system at their institute. This will include the following agenda items:

• Quantify the amount of leakage in the compressed-air system using the tank discharge method
• Evaluate the compressed air generation (energy input per volume of compressed air)
• Assess leaks with respect to energy and economic concerns and detect leaks (via ultrasound, leak spray, optical marking)
• Successively eliminate leaks and measure system leakage
• Compare the costs and benefits of the individual measures implemented

Besides achieving immediate energy savings in this specific system, the group will also develop scalable guidelines to enable other system operators at RWTH to examine their own systems for leaks and optimize them. These guidelines will include the following:

• A method for quantifying the amount of leakage in the compressed-air system
• A method for evaluating the efficiency of compressed-air generation
• A method for calculating unnecessary energy consumption and cost
• Methods for detecting leaks, including practical tips
• A cost-benefit analysis based on the study

Contact: Dr. Olivier Reinertz, Institute for Fluid Power Drives and Systems (ifas)

The Institute of Power Plant Technology, Steam and Gas Turbines (IKDG) operates a high-pressure compressor with a rated output of 6 megawatts to supply several large test rigs. Construction of a medium-pressure hall (MDH) with compressors of a lower performance class was also started a few years ago to cover the growing demand for air from additional research test rigs. In addition to a compressor with an output of 320 kilowatts that has already been installed, the installation of a second compressor (700 kilowatts) is currently being prepared. The broader range of services enables the systems to be used more in line with demand. It thus increases the supply infrastructure’s energy efficiency by saving a large amount of electricity.

During operation, the compressors must be cooled, for which, currently, fresh water is being used. Combined, the two MDH compressors require up to 50 cubic meters of fresh water per operating hour, which is taken from the water network. In comparison to the previously quite low operating hours (< 50 hours per year), a significant increase in capacity utilization (approx. 400 hours per year) is to be expected in the coming years. Given the increasing water scarcity, there is an excellent opportunity to save potable water effectively here. Members from the IKDG’s research group have developed a concept to convert the cooling water system of the MDH compressors into a closed system. The compressors are to be connected to an existing recooling system through a piping system and pump. The recooling system is to be located on the MDH’s roof. It will release the waste heat from the compressors into the exterior air and return the cooling water to the compressors in a circuit. The project aims to minimize the freshwater consumption of the MDH compressors and reduce the amount of wastewater produced by the institute and, therefore, the University. The project models how research facilities can supply their large test rigs in a sustainable and energy-efficient way.

Contact: Dr. Christian Rakut, Institute of Power Plant Technology, Steam and Gas Turbines

During one of their regular meetings, members of the Institute of Metal Forming’s workshop and management teams discussed possible energy-saving measures. The workshop staff pointed out that effective savings could be achieved quickly by eliminating leaks in the compressed-air pipes. Scientific publications typically estimate that about 15 to 50 percent of compressed air is lost through leakage (in hoses, clamps, couplings, etc.), resulting in high energy losses. As leaks are often inconspicuous and harmless, and users are not aware of the costs involved, this savings potential is often neglected. This means that eliminating leaks offers compressed air users significant potential for savings (energy/expenses). The measure aims to quickly reduce electricity consumption by helping users to identify and eliminate compressed air leaks. These savings can furthermore be retained through regular maintenance, although long-term maintenance measures are not included in this project for the time being. The project team also plans to inform all users about the leakage issue and raise their awareness of this energy loss and its environmental impact. As many labs and test facilities at RWTH institutes use compressed air, the measures can also quickly and effectively lead to energy savings at other institutes.

Contact: Dr. David Bailly, Chair of Forming Technologies and Institute of Metal Forming

As part of the discussions with Studierendenwerk on catering for the 6,000 guests at the annual RWTH Science Night on average, the question of how to make serving drinks as eco-friendly as possible arose, as did the issue of possibly offering fair-trade food. Glasses and glass bottles are not an option for safety reasons due to the great number of people. Disposable cups are highly questionable from an ecological point of view, and the rental of reusable cups would involve a considerable annual financial burden. Also, depending on where providers are based, this option could be ecologically questionable due to the potentially long distances involved. So, the attendees discussed purchasing reusable cups. 5,200 reusable cups bearing the RWTH logo could be stored in suitable boxes to save space and Studierendenwerk could clean them after use. However, the reusable cups shall not only be used for our University’s Science Nights or other Division 3.2 events. All the different university institutions will be able to rent them from Studierendenwerk for a small service fee that pays for cleaning.

Contact: Thomas von Salzen, Division 3.2 – Events and RWTHextern Citizens’ Forum

The Center for Mobile Propulsion (CMP) is a state-of-the-art research center at RWTH committed to analyzing and optimizing current and emerging propulsion technologies. Under the direction of Professor Stefan Pischinger from the Chair of Thermodynamics of Mobile Energy Conversion Systems (TME), 16 chairs and institutes are working together to develop technologies for the mobility of the future using a multi-disciplinary approach. Hydrogen is recognized as having to play a critical role as an energy carrier for stationary and mobile applications in the future. RWTH has declared hydrogen a strategic topic and, by establishing the Center for Sustainable Hydrogen Systems (CSHS) – which successfully participated in the Cluster4Future competition – it has set the course for successful research on all hydrogen-related topics. At the Hydrogen Clusters4Future, the researchers address all aspects of a hydrogen economy, from production, transportation, and storage to uses in mobility, supplying buildings with energy, and industrial applications. However, green hydrogen must first be available to research facilities to allow them to work on these research questions comprehensively. The project team aims to design a sustainable system to supply the Melaten campus with green hydrogen based on a holistic analysis of the energy and hydrogen requirements of the CMP, which already requires a significant amount of hydrogen to operate eleven system test rigs. Six work packages with a timeline of 12 months are planned. In the first work packages, the energy and hydrogen requirements are determined (demand-side management). In the following steps, the teams will assess how the CMP’s and TME’s roof space could best be utilized for integrating renewable energy sources. Finally, an energy management system is to be designed to reduce the research infrastructure’s carbon footprint and energy requirements.

Contact: Dr. Johannes Claßen, Chair of Thermodynamics of Mobile Energy Conversion Systems and Institute of Thermodynamics

Renewable energies are increasingly coming into focus in the wake of climate change. The prevention of increasing environmental catastrophes, such as last year's floods, and the dependence on fossil fuels, the negative effects of which have become strongly visible in recent weeks due to the war in Ukraine, demand an inevitable massive expansion of renewable energies in all areas. With the change of government at the federal level, this now seems to be understood and supported politically to the highest degree. In order to implement the energy turnaround on a broad scale, all other available sustainable energy sources must be developed in addition to the rapid expansion of onshore and offshore wind farms and an expansion of photovoltaic systems on the roofs of houses. One energy source that has been virtually untapped to date is wind energy in built-up areas. The expansion of small wind turbines on unused higher roofs is an ecologically and economically sensible way to sustainably develop this energy source. At the SLA, a prototype of such a small wind turbine was developed, built and tested by the applicants out of personal motivation. In order to be able to evaluate the performance of such a system in the medium term, pilot sites are being sought. The elevated flat roofs on almost all RWTH buildings offer an ideal starting situation for sustainable power generation. By using the existing building surfaces, the technology could be tested and evaluated on site. If the benefits are demonstrated to be positive, systems could be installed on all possible RWTH roof locations in a further step. In this way, RWTH can sustainably cover part of its own electricity needs by using its own wind resources. An information offer about the generated electricity can be made visible for all via an "electricity clock" at a central point.

Contact: Institute for Structural Mechanics and Lightweight Design, Professor Kai-Uwe Schröder

Group members of the student council's internal sustainability working group have recognized the problem of increased waste of resources in architectural studies. The current situation requires students to spend sums on A0 prints for presentations that are corrected by the instructor for only 15 minutes and are then disposed of. With weekly corrections, there are further additional expenses for about 30-minute corrections with the respective supervisor. The Corona pandemic has proven that such expenses and especially waste of resources are not mandatory and notes can also be taken on digital media. In order to test this and to enable more sustainable architectural teaching in the long term, we would like to purchase a Promethean Board with the help of the Sustainability Fund. We want to test the technology ourselves as well as lend it to chairs to raise awareness about alternative ways of tutoring. In this way, we also counteract the production of paper waste. Since students find themselves in such situations on a daily basis and this is a major problem, we feel that promoting resource-saving measures with the help of digital methods is a relevant part for our field.

Contact: Architecture Student Council

With the foundation of the Center for Sustainable Hydrogen Systems (CSHS) and the Center for Circular Economy (CCE), a research center of RWTH Aachen University is to be established. The aim of the building is to bundle expertise from all departments on the topics of hydrogen and the circular economy at one location. The newly created focal point for inter- and transdisciplinary research on sustainability topics will serve not only RWTH, but also the networking of stakeholders from industry, local authorities and federal states. Consequently, the research building is intended to make a significant contribution to the scientific discourse on the hydrogen and circular economy and therefore it acts as a lighthouse project. In order for the building project to fulfill this claim and thus also serve as a best-practice example beyond the region, the building itself should be designed in a circular and energy-efficient manner in addition to the implementation of the topics in terms of content. In this respect, the operating energy should be possible from future-oriented, CO2-neutral energy sources. The expertise available in the CSHS and CCE is to be used here in the form of a potential study in order to work out implementation possibilities for a holistically CO2-neutral building. The potential study includes a determination of energy requirements which, among other things, develops potentials for the integration of renewable energies. The use of an energy management system can enable continuous improvement of energy efficiency. By considering the material cycles, the input and potential output of the building fabric can be evaluated to identify future reuse potential of the materials used. At the end of the project, a guideline for cycle-appropriate and energy-optimized research buildings will be developed. The idea for the project resulted from an exchange between the CSHS and the CCE. The CSHS was initiated by a total of over 50 professors from RWTH Aachen University and Forschungszentrum Jülich. The CCE was founded in 2021 by 17 professors of RWTH Aachen University.

Contact: Junior professor for recycling in building: Junior Professor Linda Hildebrand

RWTH's building stock contributes significantly to the feeling of isolation in the various campus areas and the city of Aachen. Buildings and surrounding open spaces provide little habitat for animals and plants and often offer an unappealing image and little opportunity for students and employees to identify with their places of work. Building greenery can change this and have a positive effect on all the areas mentioned. However, large-scale building greening is associated with considerable investment and maintenance costs. The applicants from Faculties 2 and 4 and the central university administration therefore want to develop a self-construction kit for building greening together with students. This kit can be made available to students and employees by the university in order to plant smaller roof or facade sections on their own initiative. Due to its small size (self-construction approach), the "BauGrünKit" primarily supports urban biodiversity as a co-productive conservation measure. It provides habitat and food for different animal and plant species and can be adapted to specific species and locations through plant selection. The self-construction idea can be understood as a participatory approach (team-building measure), in that employees jointly install the "BauGrünKit" and jointly maintain the greenery. Through the selection of plants, the approach also holds the potential for appropriation and further development, for example in the direction of "urban gardening." In addition to easy-to-understand (graphically and textually) assembly instructions (multilingual) and intuitive usability, the BauGrünKit should also provide information about the importance of biodiversity, offer tips on how to strengthen biodiversity, and ideally inspire further greening projects. The BauGrünKit - applied in numerous ways - increases the RWTH's low biodiversity, especially in the inner city area. RWTH would thus have an easily applicable building block with which to make its contribution to preserving and strengthening biodiversity visible.

Contact: Institute and Chair of Landscape Architecture, Dr. Alex Timpe

Among the scientific staff of the institute, the question arose some time ago as to what extent a project-specific balancing of the electrical power recorded by the large number of test benches available at the institute would be possible. The background to this is that ifas has various test benches with large electrical connected loads, which are operated continuously at high loads (several hundred kW) for days or weeks during larger map measurements or durability tests. At the same time, the institute is working on the determination of the CO2 footprint in the production and operation of fluid power components as part of publicly funded projects, so that awareness of this issue is constantly growing. The project therefore aims to enable test bench and project-specific power balancing by integrating WLAN-capable power meters at neuralgic points of the institute's internal power grid. This with the aim of, on the one hand, increasing internal awareness of the effects of operation and making operation more efficient and, on the other hand, raising public awareness of this issue by indicating the amounts of energy used to generate data in publications.

Contact: Institute for Fluid Power Drives and Systems, University Professor Katharina Schmitz

The above applicants have track records in interdisciplinary H2020 and SPP projects for CO2 fixation, degradation of plastics, and electrobiotechnology, as well as experience in plant physiology, biochemistry, and modeling. Due to the effects of global warming, the need for heat-absorbing insulation in buildings is expected to increase in the future. Technological advances make it possible to incorporate additional functionalities into a facade by using "smart materials" such as microalgae or cyanobacteria. The aim of this project is to design and use a facade made of microalgae or cyanobacteria that serves three different purposes at once: First, improving the thermal insulation of a building. The living façade will consist of several modules that serve as bioreactors for the growth of microalgae or cyanobacteria. It will be attached to an existing façade, shielding the building from solar radiation and improving the building's thermal insulation and appearance. Second, the microbes bind the greenhouse gas CO2 in urban areas. Unfiltered urban air is introduced to the underside of a façade panel in combination with incoming sunlight for photosynthesis by the algae, which produce biomass and oxygen that is released at the top. Therefore, the façade has the same positive effects on air quality as a tree. Third, the cyanobacteria can fix nitrogen to form fertilizer, which is increasingly important in the current energy and Russia/Ukraine crises. Accompanying the algae reactor project, concepts for plastic avoidance and energy conservation are being implemented at the Applied Microbiology/Plant Physiology Institutes. The approaches involve students in research projects evaluating photofermentations in relation to energy balance and technical performance. This application serves as a pilot project at RWTH and can be extended to the whole facade of the Sammelbau Biologie or other building areas if the evaluation is positive.

Contact: Institute of Applied Microbiology, University Professor Lars Lauterbach