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Department of Spatial Planning

Research projects

The POWER project explores the potential of water cycles for the joint and efficient use of energy and resources in high-density mixed-use building blocks. Together with the cooperation partners, framework conditions and technical concepts for the establishment and operation of local energy and resource exchange systems based on water cycles between residential and commercial areas in inner-city redensification projects are being investigated. Two best-practice examples serve to conceptualise the exchange of energy and resources via the medium of water between residential and commercial uses. In cooperative workshops with actors from the trades and construction, technical and actor-related aspects are considered together with the urban planning framework conditions of resource exchange at the building block level and, based on this, exemplary concepts are developed for two inner-city brownfield sites. In the commercial sector, the focus is on manufacturing crafts enterprises. The aim is to identify the mutual benefits of water coupling for increasing resource and energy efficiency on the basis of the two types of use and to specify the conditions of its feasibility in order to achieve positive effects on local climate adaptation, resilience increase, energy savings and operating cost reduction for high-density building blocks.

Client: BBSR - Bundesinstitut für Bau-, Stadt- und Raumforschung

Duration: 01.01.2023 - 31.06.2023

Project partner:

ILS Research gGmbH
Institut für Städtebau und Europäische Urbanistik, RWTH Aachen
Wuppertal Institut für Klima, Umwelt, Energie gGmbH

Over the past 150 years, the demand for metals has increased sharply for key sectors such as energy, transport, manufacturing and communications. In addition to mass metals such as iron, aluminium and copper, alloying elements such as magnesium, silicon and manganese are increasingly indispensable as they fulfil important material functions for subsequent applications. The trend towards diversification of alloys continues. Technical innovations in the areas of mobility, energy conversion and storage as well as in building constructions require new functional materials again and again. However, the issue of recyclability has hardly played a role so far. At the same time, less than half of Europe's metal demand is covered by its own reserves. Europe is therefore very dependent on the globally distributed deposits. Recycling is therefore currently the only way to counteract both the dependence and the scarcity of metallic resources. Nevertheless, the recycling of alloys has its limits because the additives (for example copper in steel to increase corrosion resistance) and impurities are usually present in such low concentrations and in such a complexly distributed form that it is extremely difficult to separate them in the metallurgical process. The recirculation process thus successively leads to an undesirable accumulation in the melt. This unwanted loss of quality, so-called downcycling, is currently countered by adding primary material. A circular economy should in future make it possible to significantly reduce the proportion of added primary raw materials and also to reuse the alloying elements through the use of metallurgical real-time simulation platforms in intelligent sorting. The project, which is funded by the Federal Environment Agency, is concerned with increasing resource efficiency in the metal industry with regard to the substitution of primary raw materials by reducing downcycling. The focus is on investigating the possibilities of alloy-specific recycling of steel, aluminium, copper and zinc scrap. The investigation of different scrap fractions before and after innovative sorting and separating processes will provide new insights. In addition, control variables for up- and downcycling as well as rules for low-sort design will be determined. Based on the results of the analysis, recommendations will be developed for better exploitation of previously unused, high-value metal potentials. The evaluation benchmarks include the potential savings in raw materials and greenhouse gas emissions as well as the cost structure for the production of alloys from recycled materials. Successful provision of secondary raw materials, which means "burdened" with minimal downcycling processes, requires a comprehensive knowledge base on existing recycling structures, technological potentials, metallurgical process simulations and assessment approaches, which are being developed within the scope of this project.

Client: Umweltbundesamt
Partner: Helmholtz-Institut Freiberg für Ressourcentechnologie, Universität Augsburg, Wuppertal Institut für Klima, Umwelt, Energie

Ressourcenoptimierte Transformation von Misch- und Trennentwässerung in Bestandsquartieren mit hohem Siedlungsdruck (2019-2022)
Duration: 04/2019 to 03/2022
Further information on the project: Link to the final report


The objectives of the project TransMiT are to demonstrate and evaluate how urban development and water management aspects can be synergistically linked in the long term in neighbourhood and infrastructure planning, taking into account an overall view of resources. For this purpose, different research approaches are examined in practice in three system-characteristic existing neighbourhoods. The focus is on transformation-relevant technical and organisational aspects of the resource-optimised transformation of combined and separate drainage.

Due to more frequent heavy rainfall events, the regulatory requirements for flood protection of buildings and properties have become increasingly stringent in recent years. The goal of the sub-project at the TU Dortmund University is to investigate the potential suitability of roof surfaces for drainage and flood protection-relevant precipitation retention. The investigations include measurement surveys of the runoff behaviour of the roof surfaces, their monitoring, evaluation of the results and transfer to the selected urban districts.

Further information on funding: Bundesministerium für Bildung und Forschung (BMBF)

Contact person: Prof. Dr.-Ing. Mathias Kaiser, Jana-Marie Storchmann

Further participants:

Institut für Siedlungswasserwirtschaft und Abfalltechnik (ISAH)
Institut für Siedlungswasserwirtschaft der TU Braunschweig (ISWW)
Institut für Infrastruktur und Ressourcenmanagement (IIRM)
Institut für Kartographie und Geoinformatik (ikg)
Stadtentwässerung Hannover, Eigenbetrieb der Landeshauptstadt Hannover (SEH)
Landeshauptstadt Hannover, Fachbereich Umwelt und Stadtgrün (LHH – FB 67.10)
Stadtentwässerung Hildesheim (SEHi)
Stadtentwässerung Braunschweig GmbH (SEBS)
Wohnungsgenossenschaft Gartenheim eG (GH)
Spar- und Bauverein eG (spar + bau)
bpi Hannover
aquaplaner Ingenieurgesellschaft für Wasserwirtschaft, Umwelt, Abwasser
plan zwei Stadtplanung und Architektur

Auftraggeber: Umweltbundesamt

Projektleitung: Ernst & Young Law GmbH

Projektpartner: Ernst & Young Law GmbH und Ernst & Young Wirtschaftsprüfungsgesellschaft GmbH

Projektlaufzeit: 05/2021 bis 08/2022

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