Stefanie Hellweg


Last Name

Hellweg

First Name

Stefanie

ORCID

0000-0001-6376-9878

Organisational unit

03732 - Hellweg, Stefanie / Hellweg, Stefanie

Search Results

Publications 1 - 10 of 150
  • Time- and site-dependent life cycle assessment of thermal waste treatment processes
    Item type: Other Journal Item
    Hellweg, Stefanie (2001)
    The International Journal of Life Cycle Assessment
  • A novel machine-learning approach for evaluating rebounds-associated environmental footprint of households and application to cooperative housing
    Item type: Journal Article
    Shinde, Rhythima; Froemelt, Andreas; Kim, Aleksandra; et al. (2022)
    Journal of Environmental Management
    Multiple environmental policies aim to increase resource efficiency and reduce consumption of goods and services with high environmental impact. This may lead to cost-savings and, consequently, additional consumption with environmental impacts (rebound effects). In this study, a supervised machine-learning model (i.e. an application of random forest regression) is developed to quantify consumption rebound effects. In contrast to previous approaches, it is a versatile method, which allows to estimate any income-related rebound at household level considering specific household properties and the entire profile of consumption. Socio-economic properties (e.g. income, age group) of the households are used as the independent properties for the regressor to detect the dependent consumption expenses of the households. Thus, this method can be used as a bottom-up study for understanding rebounds and developing targeted measures to prevent or reduce rebound effects. To illustrate the application of the method, it is applied to the case of cooperative housing in Switzerland. In addition to environmental goals, the cooperative aims to provide affordable housing, and the reduced rent increases the disposable income of tenants. The results show that households tend to spend the ‘extra’ income on housing (e.g. for larger apartments) and travel. For the former, the cooperative already has a policy in place regulating the apartment area permitted per person, which delimits induced environmental impacts. For the latter, households with lower income particularly spend their extra-money on purchase and operation of vehicles, while higher-income groups rather spend it on recreation and package holidays. Travel, housing, clothing and personal care products have highest emissions per Swiss Franc (∼0.3–0.6 kg CO2-eq/CHF). Thus, it is recommended to provide incentives for shifting these expenses to other consumption, to avoid jeopardizing environmental goals. The method was also used for a range of other applications e.g. rebounds due to energy-efficient devices to illustrate its versatility.
  • Spatial optimization of industrial symbiosis for heat supply of agricultural greenhouses
    Item type: Journal Article
    Rezaei, Farzaneh; Burg, Vanessa; Pfister, Stephan; et al. (2024)
    Journal of Industrial Ecology
    Despite the many benefits of greenhouses, it is challenging to meet their heating demand, as greenhouses belong to the most energy-intensive production systems in the agriculture sector. Industrial symbiosis can bring an effective solution by utilizing waste heat from other industries to meet the greenhouse heat demand. This study proposes an optimization framework by which optimum symbiotic relationships can be identified. For this aim, the spatial analysis is integrated into an optimization model, in which geographical, technical, and economic parameters are considered simultaneously to identify the optimal location for developing new agricultural greenhouses. The objective function is to minimize the heating costs, that is, the investment cost of piping and electricity cost for pumping heat-carrying fluid from supplier to demand. The model is applied to the case study of Switzerland, and currently existing municipal solid waste incinerators, cement production plants, and biogas plants are considered potential waste heat sources. Results show that the import of tomato, cucumber, and lettuce to Switzerland can theoretically be replaced by vegetable production in new waste-heat supplied greenhouses (zero import scenarios). Accounting for the economy of scale for pipeline investment costs leads to selecting large-scale greenhouses with a cost reduction of 37%. The optimization results suggest that 10% of the greenhouses needed to satisfy the total domestic demand for lettuce, tomato, and cucumber could be placed on a suitable land plot in the direct vicinity of a waste heat source, with low costs of waste heat supply.
  • Linking energy scenarios and waste storylines for prospective environmental assessment of waste management systems
    Item type: Journal Article
    Meylan, Grégoire; Haupt, Mélanie; Duygan, Mert; et al. (2018)
    Waste Management
  • Uncertainty Analysis in Life Cycle Assessment (LCA): Case Study on Plant - Protection Products and Implications for Decision Making
    Item type: Other Journal Item
    Geisler, Georg; Hellweg, Stefanie; Hungerbühler, Konrad (2005)
    The International Journal of Life Cycle Assessment
  • Correction to GIS-Based Regionalized Life Cycle Assessment: How Big Is Small Enough? Methodology and Case Study of Electricity Generation (vol 46, pg 1096, 2012)
    Item type: Other Journal Item
    Mutel, Christopher L.; Pfister, Stephan; Hellweg, Stefanie (2012)
    Environmental Science & Technology
  • Anticipating Urban Land Use Change in Polycentric Regions
    Item type: Other Conference Item
    Räth, Yves M.; Miotti, Marco; van Strien, Maarten J.; et al. (2025)
  • About Shoes, Cucumbers, Beer and Cars: A Bottom-Up Household Consumption LCA-Model
    Item type: Other Conference Item
    Froemelt, Andreas; Walker, Christie; Dürrenmatt, David; et al. (2017)
    Conference Programme of the ISIE-ISSST 2017: Science in Support of Sustainable and Resilient Communities
  • Cumulative exergy extraction from the natural environment (CEENE): a comprehensive life cycle impact assessment method for resource accounting
    Item type: Journal Article
    Dewulf, Jo; Boesch, Michael E.; de Meester, Bram; et al. (2007)
    Environmental Science & Technology
    The objective of the paper is to establish a comprehensive resource-based life cycle impact assessment (LCIA) method which is scientifically sound and that enables to assess all kinds of resources that are deprived from the natural ecosystem, all quantified on one single scale, free of weighting factors. The method is based on the exergy concept. Consistent exergy data on fossils, nuclear and metal ores, minerals, air, water, land occupation, and renewable energy sources were elaborated, with well defined system boundaries. Based on these data, the method quantifies the exergy “taken away” from natural ecosystems, and is thus called the cumulative exergy extraction from the natural environment (CEENE). The acquired data set was coupled with a state-of-the art life cycle inventory database, ecoinvent. In this way, the method is able to quantitatively distinguish eight categories of resources withdrawn from the natural environment: renewable resources, fossil fuels, nuclear energy, metal ores, minerals, water resources, land resources, and atmospheric resources. Third, the CEENE method is illustrated for a number of products that are available in ecoinvent, and results are compared with common resource oriented LCIA methods. The application to the materials in the ecoinvent database showed that fossil resources and land use are of particular importance with regard to the total CEENE score, although the other resource categories may also be significant.
  • Circularity metrics and indicators for construction: gaps in current assessment methodologies and recommendations towards a standardized approach
    Item type: Conference Paper
    Lozach, Loïs; Hellweg, Stefanie (2025)
    Journal of Physics: Conference Series
    Circular economy is an attractive concept for the building sector, which aims to operationalize sustainability by reducing its embodied emissions and resource consumption. Many circularity metrics have been developed to monitor these strategies, but they rely on heterogeneous methodologies that reflect a lack of consensus on the definition of circular economy. To help building stakeholders decide which metrics to use, we conducted a literature review of circularity metric research published between 2010 and 2025. We then developed a circularity assessment workflow and a taxonomy of circularity metrics across life cycle stages and circularity strategies. Results show that the construction and use phases are not well covered by existing circularity metrics, which mostly focus on closing material loops within design and end-of-life stages. We recommend using the established methods of material flow analysis and life cycle assessment as an inspiration to support the development of appropriate circularity metrics by (1) preserving functional properties of materials, products and buildings, (2) conducting multi-indicator assessments, and (3) returning to a traditional workflow that defines circularity goals and scope before developing tailored metrics (instead of vice versa, as often performed in the literature).
Publications 1 - 10 of 150