Contributions published at Informatics and Sustainability Research (Lorenz Hilty)
|Roland Hischier, Mohammad Ahmadi Achachlouei, Lorenz Hilty, Evaluating the sustainability of electronic media: Strategies for life cycle inventory data collection and their implications for LCA results, Environmental Modelling & Software, 2014. (Journal Article)
This paper compares two Life Cycle Assessment (LCA) studies independently carried out to assess the environmental impacts of electronic versus print media. Although the two studies lead to the same overall conclusion for the case of a news magazine – namely that the tablet version of the magazine has environmental advantages over the print version – there are significant differences in the details of the LCA results. We show how these differences can be explained by differences in the methodological approaches used for Life Cycle Inventory (LCI) modelling, in particular the use of rough average data versus the attempt to use the most specific and detailed data as possible. We conclude that there are several issues in LCA practice (at least when applied in the domain of media) that can significantly influence the results already at the LCI level: The data collection strategy used (e.g. relying on desk-based research or dismantling a device under study) and the decisions made at inventory level with regard to parameters with high geographic variability, such as the electricity mix or recycling quotas.
|Sai Anandita Kuchibhotla, Environmental impact of media use in teaching and learning at the Department of Informatics, University of Zurich, Faculty of Economics, 2014. (Bachelor Thesis)
This bachelor thesis studies the environmental impact caused by the use of lecture notes by Informatics students at the University of Zurich. For this, the life cycle assessment methodology was applied and the product systems were modeled and assessed with Umberto NXT LCA. Three electronic media (desktop computer, laptop computer, tablet computer) and two print media (self-printed lecture notes, printed books of lecture notes) were taken into consideration for the impact assessment. Alternative scenarios were also assessed to identify strategies aiming at an improvement of the environmental performance. On the basis of the results of this research, it can be concluded that the current use of multiple media to study lecture notes is not environmentally preferred. The results suggest that desktop computer and self-printed lecture notes are the least preferred media and the shift to a purely laptop or tablet computer-based strategy can improve the current environmental performance by up to 80%. Even a combination of printed books, provided by the University, and tablet computer optimizes the current scenario by 42%.
|Esther Müller, Lorenz Hilty, Rolf Widmer, Mathias Schluep, Martin Faulstich, Modeling metal stocks and flows - a review of dynamic material flow analysis methods, Environmental Science & Technology, 2014. (Journal Article)
Dynamic material flow analysis (MFA) is a frequently used method to assess past, present, and future stocks and flows of metals in the anthroposphere. Over the last fifteen years, dynamic MFA has contributed to increased knowledge about the quantities, qualities, and locations of metal-containing goods. This article presents a literature review of the methodologies applied in 50 dynamic MFAs of metals. The review is based on a standardized model description format, the ODD (Overview, Design concepts, Details) protocol. We focus on giving a comprehensive overview of modeling approaches and structure them according to essential aspects, such as their treatment of material dissipation, spatial dimension of flows, or data uncertainty. The reviewed literature features similar basic modeling principles, but very diverse extrapolation methods. Basic principles include the calculation of outflows of the in-use stock based on inflow or stock data and a lifetime distribution function. For extrapolating stocks and flows, authors apply constant, linear, exponential, and logistic models, or approaches based on socioeconomic variables, such as regression models or the intensity-of-use hypothesis. The consideration and treatment of further aspects, such as dissipation, spatial distribution, and data uncertainty, vary significantly and highly depends on the objectives of each study.
|Robert Dewor, Energy efficiency of web applications, University of Zurich, Faculty of Economics, 2014. (Master Thesis)
The increase of web applications and web services is a contributing factor to the yearly increase of emissions caused by the ICT Industry. The goal of this master thesis is to develop an evaluation method for the energy efficiency of web applications by identifying a collection of criteria for their energy efficiency. Those criteria then provide information on what areas the web application could be improved in order to be more energy efficient. Based on those criteria an evaluation model is created. This model will then be applied to an example web application. After that problems and challenges that arose during the development of this thesis are discussed.
|Adrian Benz, Entscheidungsverhalten in agentenbasierten Modellen: Literaturrecherche und Entwicklung einer Agenten-Testumgebung, University of Zurich, Faculty of Economics, 2014. (Master Thesis)
In a project realized at the Swiss Federal Institute for Forest, Snow and Landscape (WSL), the Swiss wood market has been modelled on the basis of an agent-based model. This master thesis builds on that project and provides some supporting work. A literature research has been initially conducted. The objective of that research was to find different modelling approaches of agent decision-making behaviour. In the context of this literature study, the focus has been set on energy markets. In this thesis, the discovered models are described and additionally summarized in a table. To evaluate different decision-making behaviours, an Agent-Testbed has been developed in a second step. This test-framework has been programmed as a basic Java application. Various decision-making behaviours, which were developed in the context of this work, have been integrated into this test-framework. By this way, the evaluation of these behaviours has been enabled. The performance as well as the possibility to reconstruct the behaviour of one approach by a different approach has been analysed.
|Niels Kübler, Portierung und Weiterentwicklung von TBDis
auf Symfony mit dem Schwerpunkt
Sicherheit, University of Zurich, Faculty of Economics, 2014. (Bachelor Thesis)
Discussions are often implying difficulties for their participants. In order to face up to these problems, the CANDis project has been launched in 2010. The goal of this bachelor thesis is improving and extending the existing prototype of a debate support system (TBDis - to be discussed). In the process of improvement, the existing application has been ported to the PHP framework Symfony. The focus of this thesis is on security: Cross-Site-Request-Forgery, Cross-Site-Scripting and SQL-Injection and their countermeasures are explained in detail. Based on these findings, the security concept of TBDis has been improved, which facilitates a beta phase.
|David Aggeler, Potentiale des Smart Meters für den Schweizer Strommarkt und Zielkonflikte hinsichtlich des Datenschutzes, University of Zurich, Faculty of Economics, 2014. (Bachelor Thesis)
Due to its hierarchical structure and the unidirectional flow of current, the traditional power grid is going to its limits. Furthermore the liberalization of Switzerland's electricity market comes along. Other political developments aim at a reduction of fossile energy sources, at an increase in renewable energy sources for electricity production, a step-by-step phase-out of nuclear energy and a reduction in energy consumption. As a result the swiss power grid has to face a series of challenges. The swiss power grid needs to be enhanced - for example to a smart grid - to be able to achieve the technical and political goals. Moreover the application of smart meters can help to achieve these goals. This bachelor thesis aims at showing the potential of smart meters for Switzerland's electricity market and at discussing the conflict of goals regarding data privacy when applying smart meters. On one hand the application of smart meters enables remote meter reading, giving households a detailed feedback about its electricity consumption, or the introduction of different tariffs. On the other hand there are several risks to consider when using smart meters. These risks concern mostly data privacy and data integrity. There exist various approaches to ensure data privacy and data integrity as good as possible. One approach, which is based on the insights gained in this bachelor thesis, is grounded on the concept of paying electricity before using it.
|Vlad C. Coroama, Lorenz Hilty, Assessing Internet energy intensity: A review of methods and results , Environmental Impact Assessment Review , Vol. 45, 2014. (Journal Article)
Assessing the average energy intensity of Internet transmissions is a complex task that has been a controversial subject of discussion. Estimates published over the last decade diverge by up to four orders of magnitude — from 0.0064 kilowatt-hours per gigabyte (kWh/GB) to 136 kWh/GB. This article presents a review of the methodological approaches used so far in such assessments: i) top–down analyses based on estimates of the overall Internet energy consumption and the overall Internet traffic, whereby average energy intensity is calculated by dividing energy by traffic for a given period of time, ii) model-based approaches that model all components needed to sustain an amount of Internet traffic, and iii) bottom–up approaches based on case studies and generalization of the results. Our analysis of the existing studies shows that the large spread of results is mainly caused by two factors: a) the year of reference of the analysis, which has significant influence due to efficiency gains in electronic equipment, and b) whether end devices such as personal computers or servers are included within the system boundary or not. For an overall assessment of the energy needed to perform a specific task involving the Internet, it is necessary to account for the types of end devices needed for the task, while the energy needed for data transmission can be added based on a generic estimate of Internet energy intensity for a given year. Separating the Internet as a data transmission system from the end devices leads to more accurate models and to results that are more informative for decision makers, because end devices and the networking equipment of the Internet usually belong to different spheres of control.
|Fethullah Goekkus, Energy efficient programming: an overview of problems, solutions and methodologies, University of Zurich, Faculty of Economics, 2013. (Bachelor Thesis)
There has been a lot of research activity in the field of energy efficiency of ICT systems, which mainly focus on the hardware side, where the software aspects remained relatively unexplored. However software can influence the energy efficiency of hardware significantly, since all hardware is controlled by software. This bachelor thesis provides an overview of the most important problems and proposed solutions regarding the energy efficiency of software and to elucidate the software methodologies and designs that can be used to reduce energy demand of ICT systems, as well as describe diverse tools that assist in development of energy-efficient software.
|Samuele Zoppi, Simulating an adaptive heating and cooling system, University of Zurich, Faculty of Economics, 2013. (Master Thesis)
In this thesis the model of a combined heating and cooling system is developed in order to assess potential energy and costs savings. The system has been modeled using the discrete event simulation paradigm, while the model has been implemented with the help of the Desmo-J (Discrete Event Simulation Modeling in Java) framework. The model flexibility allows to simulate very different scenarios, since a different parametrization can be applied to the heating and cooling system configuration, the control strategy used, the pricing model chosen as well as to the energy demands. Different experiments investigating the potential savings of using different price models and energy capacities of the system storages have been executed. The results show that the largest savings are reached by increasing the energy capacity of the waste heat storage and by the use of a spot market based pricing model.
|Lorenz Hilty, Smart solutions, energy efficiency, and sustainability – updating the research agenda for environmental informatics, In: EnviroInfo 2013 – 27th International Conference on Informatics for Environmental Protection, Shaker Verlag, Aachen, 2013-09-02. (Conference or Workshop Paper published in Proceedings)
"Smart" solutions have considerable transformational power. From the perspective of Environmental Informatics, it is an open question whether a specific smart solution (e.g., a smart home application) is more energy efficient than a conventional solution and under which conditions even a more energy efficient solution is more sustainable. This pa-per provides ideas and arguments why we should take a broader perspective in research and development, taking into account the life cycle of ICT products, the dynamics of economic systems, and emerging risks for basic rights, and how these challenges can be integrated into the research agenda of Environmental Informatics.
|Nikolaus A Bornhöft, Bernd Nowack, Lorenz Hilty, Material flow modelling for environmental exposure assessment – a critical review of four approaches using the comparative implementation of an idealized example, In: EnviroInfo 2013 – 27th International Conference on Informatics for Environmental Protection, Shaker Verlag, Aachen, 2013-09-02. (Conference or Workshop Paper published in Proceedings)
Newly developed materials such as engineered nanomaterials are produced in increasing amounts and applied in a growing number of products. Once released to the environment, they can pose a hazard to ecosystems and human health. To assess potential risks, the exposure of the material to humans and the environment has to be determined. For many materials such as engineered nanomaterials, a quantitative measurement of environmental concentrations is not feasible. Material flow models can be used to determine these concentrations indirectly by predicting material flows in the environment. Several modelling approaches can be applied to represent existing knowledge about the flows of materials into and between environmental media or compartments and to consider the uncertainty and variability of the input parameters. In this study we evaluate four existing approaches with regard to their capabilities for indirect exposure assessment, focusing on their ability to treat uncertainty. We first explain how we preselected the four most promising modelling approaches: material flow analysis, system dynamics, material flow networks, and probabilistic material flow modelling. We then define a set of evaluation criteria based on the requirements of environmental exposure assessment and develop a simplified example system that is designed to test these criteria. Based on the comparative modelling and implementation of the example system, we discuss the capabilities and limitations of the approaches and indicate what is missing for a reliable environmental exposure prediction using material flow modelling.
|Lorenz Hilty, Nikolaus A Bornhöft, Smart grid integration of an existing office building: modelling and simulation of adaptation strategies, In: EnviroInfo 2013 – 27th International Conference on Informatics for Environmental Protection, Shaker Verlag, Aachen, 2013-09-02. (Conference or Workshop Paper published in Proceedings)
The development of smart grids makes possible the introduction of dynamic electricity rates, with prices changing each hour. Dynamic rates can reflect the temporal dependency of supply and demand for electrical power and network capacity, thus avoiding load peaks and promoting the use of fluctuating renewable energy sources. We present a simulation model that studies the electricity demand for heating and cooling modern office buildings in the context of dynamic electricity prices. The model permits the simulation of scenarios in which existing thermal energy reservoirs (warm and cold water tanks) are used for the smart grid integration by means of adapted control strategies. The adaptation to dynamic electricity rates – and thus indirectly to the fluctuating supply of wind and solar power – is achieved solely by changing the control of the existing infrastructure without changing the infrastructure itself.
|Malte Spielberger, Design Science Research - Methode und Anwendung im Rahmen einer Fallstudie: die Anwendung von Design Science am Beispiel der Entwicklung einer Marktplatzlösung für die Studierendenplattform uniboard.ch, University of Zurich, Faculty of Economics, 2013. (Bachelor Thesis)
The present thesis takes on the task of planning, designing and developing a marketplace system for the online platform uniboard.ch using the methodology Design Science Research and the Design Science Research Cycles Hevner et al. (2004) introduced. Initial situation was the existence of rudimentary solution for the users of the student community, which were able to sell there not anymore used goods, notably their compulsory literature of passed university courses. This solution was no suitable, long lasting solution because it lacked good usability and was based on the forum functionality. Using Hevners et al. (2004) provided method of the Design Science Research and the validation of the solution against the guidelines and checklist that were provided, the marketplace was developed successfully.
|Frida Juldaschewa, Motivation im Crowdsourcing: ein Überblick, University of Zurich, Faculty of Economics, 2013. (Bachelor Thesis)
Due to the functionalities of the Internet and particularly of the Web 2.0 it is possible for people to work collaboratively in virtual space. Companies and individuals use this opportunity and post tasks on the Internet, that can then be solved by Internet users. This phenomenon, called Crowdsourcing, is increasingly used as a business model. This bachelor thesis addresses the motivation of people to work on Crowdsourcing tasks. The results show that different motivators exist for different types of Crowdsourcing. Depending on the type of the task, the ideology of the platform, the identification with the community, the remuneration and the type of collaboration, the motivation of the workers differs in its origin. On collaborative platforms like Wikipedia or Open Source Software it is mainly the common ideology and the strong identification with the community, that motivates the workers to contribute to a greater cause. On competitive platforms like InnoCentive, in contrast, the cash prizes, the career opportunities and the social recognition play the major roles. Tasks on Mechanical Turk are mostly solved for the remuneration. Crowdsourcing platforms with creative tasks motivate users to a great extent by giving them the chance to apply their creativity and expand their skills as well as establish their reputation and improve their career opportunities. Crowdsourcing applications in the form of online games are popular because the participants have fun playing the game and want to develop their player status.
|Alexander Mülli, Optimierung einer bestehenden Applikation zur Findung optimaler "Schnittmuster" für Bäume und Waldbestände, University of Zurich, Faculty of Economics, 2013. (Bachelor Thesis)
The goal of this thesis is to analyse a log bucking simulation software and how its algorithm for finding optimal cut sequences could be improved. Problem solving methods as Greedy Algorithm and Dynamic Programming are discussed and then applied to the software. An evaluation of the new implementation with field data was able to show improvements in yield value and runtime performance.
|Nikolaus A Bornhöft, Lorenz Hilty, Sutharshini Rasathurai, Simulation der Smart-Grid-Integration eines modernen Bürogebäudes am Beispiel von IBM-Schweiz, In: BUIS-Tage: IT-gestütztes Ressourcen- und Energiemanagement, Springer, Berlin Heidelberg, 2013-04-24. (Conference or Workshop Paper published in Proceedings)
Die Entwicklung von Smart Grids ermöglicht die Einführung dynamischer Stromtarife, etwa mit sich stündlich ändernden Preisen. Diese können der zeitlichen Abhängigkeit von Angebot und Nachfrage nach elektrischer Energie und Netzkapazität Rechnung tragen, dadurch Lastspitzen vermeiden und die Nutzung fluktuierender erneuerbarer Energiequellen begünstigen. Wir stellen ein Simulationsmodell vor, das den hohen Strombedarf für die Beheizung und Kühlung moderner Bürogebäude im Kontext dynamischer Strompreise untersucht. Das Modell erlaubt die Simulation von Szenarien, in denen vorhandene thermische Energiespeicher (Warm- und Kaltwassertanks) durch eine angepasste Steuerung und Regelung gezielt für die Smart-Grid-Integration genutzt werden. Das Modell wurde im Rahmen einer Diplomarbeit an der Universität Zürich in Zusammenarbeit mit IBM-Research entwickelt und am Beispiel des Gebäudes von IBM-Schweiz erprobt. Insbesondere wurden die Einsparpotentiale abgeschätzt, die eine Anpassung der Steuerung der bestehenden Anlage unter der Annahme dynamischer Strompreise bietet. Im Modell konnte unter diesen Annahmen für den untersuchten Sommermonat Juni eine Einsparung von 31 % der Energiekosten erreicht werden.
|David Oertle, Plattform für den Handel von Ressourcen innerhalb eines Unternehmens am Beispiel von CO2-Zertifikaten für Dienstreisen, University of Zurich, Faculty of Economics, 2013. (Master Thesis)
The master thesis at hand investigates how a company, supported by a Cap & Trade System, can regulate limited resources by restricting the tradable permissions for the emission of the respective resource. The focus this master thesis lays in the development of a software application in which the consumption or emission of a resource can be calculated and traded with the therefore necessary permissions. Moreover, this thesis examines how the incentives and business processes should be structured within a company so that the minimization of a resource can be successfully implemented with the support of the application. The reduction of CO2 emissions caused by business related travel serves as a concrete example of the application.
|Stefan Badertscher, Generalisierung des intra-organisationalen Cap and Trade, University of Zurich, Faculty of Economics, 2013. (Master Thesis)
Adequate handling of environmental resources is a theme which is becoming more and more important in the near future. In particular, bigger companies have a major impact on the environment due to emissions which are released. When in the future the cost for using environmental resources is getting higher, there will be a direct impact on economic performance as using resources will cost more. The following Master’s thesis deals with exactly this problem. The aim is to fulfil the same missions but with fewer resources, such as an 80% usage of environmental resources. This reduction should not have any impact; it should just be achieved in implementing an efficient market for the internal use of a company’s resources. Hence, one main part of the Master’s thesis was the identification of areas in a company which can be used for economization of resources. The other main part of the Master’s thesis was a proof of concept. For that, a plugin for calculating the CO2-usage was implemented using real life data. The accuracy of the data was achieved by using an external API. At the end an evaluation with stakeholders has been performed. In the final step the evaluation has been interpreted and presented in a graphical way in order to provide links for future continuation.
|Lorenz Hilty, Britta Oertel, Michaela Wölk, Identifying, Tracking and Tracing: From Geographic Space to Cyberspace and Back, In: PACITA 2013, The European Technology Assessment Conference: Technology Assessment and Policy Areas of Great Transitions. 2013. (Conference Presentation)
An increasing amount of technologies are being used that involve information on the location of objects or persons. In addition to the widely known geolocation by satellite via GPS, today at least 12 more technologies are being used that make it possible to determine the location of devices, and indirectly that of their users, such as GSM/UMTS, WLAN, RFID, optical or even acoustical technologies (for details see Hilty et al., 2012). This may happen in real time (tracking) or after a delay depending on the technology (tracing); it may happen with a degree of precision ranging from a few kilometers to a few centimeters, and either with or without the knowledge of the persons affected. The mix of technologies in use today bears greater privacy risks than the relatively manageable RFID technology, which created a public debate some years ago (Oertel et al., 2005). Because tracking and tracing can be technically implemented with increasing convenience and decreasing cost, more and more location data are being generated and stored. When the results of many positioning processes are combined, movement profiles, or even relationship profiles, can be done on persons. In addition to navigation, there are numerous other application areas of localization technologies: location-based services, micromarketing, calculation of fees and insurance premiums, surveillance of individuals (for health reasons or in law enforcement), emergency missions, documentation, and forensic evidence. Localization technologies offer many societal opportunities, e.g. for promoting public transportation (easier to find connections and to pay for them), for emergency and rescue operations, for personal security and orientation at unfamiliar locations, for meeting friends and perhaps even for making friends among strangers. They may even provide a technological basis for the vision of a sustainable information society that has been around for a decade (Dompke et al., 2004; Som et al., 2009). However, as localization technologies become more readily accepted, society is becoming more dependent on them. They are becoming new critical infrastructures the malfunctioning or collapse of which can have far-reaching consequences comparable with a breakdown of the telephone network. Manipulated localization information may have even more serious consequences than a lack of information, because it can misguide vehicles, persons and freight.