Global Warming Potential of a Smartphone : Using Life Cycle Assessment Methodology

Detta är en Master-uppsats från KTH/Industriell ekologi

Författare: Elif Mine Ercan; [2013]

Nyckelord: ;


The global development and usage of smartphones are rapidly increasing. Further, the high capacity and functionality of these devices indicate high technological manufacturing processes and complex supply chains. Thus it is of interest to investigate the potential environmental impacts of a smartphone, from a life cycle perspective.

This study uses a Life Cycle Assessment (LCA) methodology in order to evaluate the potential environmental impacts of a smartphone, in particularly the smartphone Sony XperiaTM T. Environmental in- and outflows, including resources, emissions to air, water and soil as well as waste treatment and electric energy consumption are quantified for the entire life cycle of the smartphone. The system boundary for the LCA includes raw material acquisition, production, in- and outbound transportation, utilization and end-of-life treatment for a smartphone with an estimated lifetime of 3 years. All phone components and processes as well as the charger, USB-Cable, headset, delivery box, instruction manuals and the use of network infrastructure have been included within this boundary. The data collection process involved dismantling and analyzing a Sony XperiaTM T smartphone to gain knowledge on the hardware and collecting information from Sony Mobile and Ericsson Research and partially from external sources for major smartphone processes. GaBi 6.0 Software was used for the modeling and analysis. Sensitivity analysis was performed on different parameters of the model to evaluate the effects of the assumptions and methodological choices adopted for the study. The chosen characterization model for this study is established by the Institute of Environmental Sciences (CML). The analysis of the LCA results focus on the CML global warming potential (GWP) impact category and present figures representing the carbon dioxide equivalents (kg CO2e) for each life cycle stage of the smartphone.

According to this LCA study, the Sony XperiaTM T smartphone, excluding accessories and network usage, produces a total of 45 kg CO2e to the atmosphere during its entire lifetime, when considering medium usage and a Swedish electricity mix for the use stage. This corresponds to the amount released when driving an average European car for approximately 300 km. The life cycle stage that is calculated to have the most significant environmental impact on the results is the production stage, accounting for just above 30 kg CO2e. Activities with main contributions to the total GWP impact include integrated circuit (IC) production, phone shell raw material acquisition and production followed by smartphone assembly and distribution. If accessories and mobile network are included, the total life cycle impact is 68 kg CO2e for the assessed scenario. As no results are available for other impact categories, no conclusions can be made related to impacts such as eutrophication and acidification.

If a global electricity mix is applied, the total results for the smartphone including accessories and network usage increase to 117 kg CO2e for the moderate user scenario for the 3 year life cycle period. This corresponds to approximately 40 kg CO2e per year which is equivalent to the amount released when driving an average European car for 270 km. Excluding accessories and network usage, the life cycle impact for the smartphone for this alternative is 51 kg CO2e.

A parameter model in Microsoft Excel, based on multiple parameters, has also been constructed as an integrated part of this study. This parameter model is aimed to provide results for smartphone models that differ in look and performance and also aimed to be applied for tablets.

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