Environmental Benefits of Repurposing Smartphones in Building Automation

Ana Bendiek-Laranjo; Didier Beloin-Saint-Pierre; Marvin Schwander; Catherine De Wolf; Hanmin Cai

doi:10.55845/jos-2025-1230

Authors

Ana Bendiek-Laranjo Urban Energy Systems Laboratory, Empa; Department of Civil, Environmental and Geomatic Engineering, ETH Zurich https://orcid.org/0009-0006-1720-6031
Didier Beloin-Saint-Pierre Technology and Society Laboratory, Empa https://orcid.org/0000-0003-1214-8195
Marvin Schwander Department of Information Technology and Electrical Engineering, ETH Zurich
Catherine De Wolf Department of Civil, Environmental and Geomatic Engineering, ETH Zurich https://orcid.org/0000-0003-2130-0590
Hanmin Cai Urban Energy Systems Laboratory, Empa https://orcid.org/0000-0001-7435-0239

DOI:

https://doi.org/10.55845/jos-2025-1230

Keywords:

Building Automation, Circular Economy, Waste from Electrical and Electronic Equipment (WEEE), Life Cycle Assessment, Reuse, Repurpose

Abstract

While intelligent energy systems can enhance the energy efficiency of buildings, the production and transportation of related digital equipment, such as sensors and control units, can offset the efficiency benefits by increasing resource consumption and environmental impacts from the installation. This study investigates the potential environmental benefits of using discarded smartphones instead of traditional programmable logic controllers (PLCs) to evaluate if equipment for building automation can become more sustainable. A life cycle assessment of both technologies is conducted using the ecoinvent v3.10 cut-off database, the OpenLCA software, and the ReCiPe 2016 midpoint (H) method. Results show that repurposed smartphones significantly reduce the environmental impacts of control units compared to PLCs, with notable reductions in toxicological stress on human health and freshwater eutrophication. Findings about the electricity consumption of manufacturing steps, i.e. the primary contributor to environmental impacts, make this study of the environmental benefits from cross-sector reuse strategies relevant beyond their uses in buildings.

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References

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