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Electric mobility is beginning to enter East African cities. This paper aims to investigate what policy-level solutions and stakeholder constellations are established in the context of electric mobility (e-mobility) in Dar es Salaam, Kigali, Kisumu and Nairobi and in which ways they attempt to tackle the implementation of electric mobility solutions. The study employs two key methods including content analysis of policy and programmatic documents and interviews based on a purposive sampling approach with stakeholders involved in mobility transitions. The study findings point out that in spite of the growing number of policies (specifically in Rwanda and Kenya) and on-the-ground developments, a set of financial and technical barriers persists. These include high upfront investment costs in vehicles and infrastructure, as well as perceived lack of competitiveness with fossil fuel vehicles that constrain the uptake of e-mobility initiatives. The study further indicates that transport operators and their representative associations are less recognized as major players in the transition, far behind new e-mobility players (start-ups) and public authorities. This study concludes by identifying current gaps that need to be tackled by policymakers and stakeholders in order to implement inclusive electric mobility in East African cities, considering modalities that include transport providers and address their financial constraints.

Electromobility is a new approach to the reduction of CO2 emissions and the deceleration of global warming. Its environmental impacts are often compared to traditional mobility solutions based on gasoline or diesel engines. The comparison pertains mostly to the single life cycle of a battery. The impact of multiple life cycles remains an important, and yet unanswered, question. The aim of this paper is to demonstrate advances of 2nd life applications for lithium ion batteries from electric vehicles based on their energy demand. Therefore, it highlights the limitations of a conventional life cycle analysis (LCA) and presents a supplementary method of analysis by providing the design and results of a meta study on the environmental impact of lithium ion batteries. The study focuses on energy demand, and investigates its total impact for different cases considering 2nd life applications such as (C1) material recycling, (C2) repurposing and (C3) reuse. Required reprocessing methods such as remanufacturing of batteries lie at the basis of these 2nd life applications. Batteries are used in their 2nd lives for stationary energy storage (C2, repurpose) and electric vehicles (C3, reuse). The study results confirm that both of these 2nd life applications require less energy than the recycling of batteries at the end of their first life and the production of new batteries. The paper concludes by identifying future research areas in order to generate precise forecasts for 2nd life applications and their industrial dissemination.

Die weltweite Nutzung von Energie aus erneuerbaren Quellen wie Wind, Sonne, Biomasse, Wasser oder Erdwärme steigt kontinuierlich. Eine Vielzahl von Ländern hat im Rahmen ihrer Aktivitäten zum Klimaschutz Ziele für den zukünftigen Ausbau von erneuerbarer Energien verabschiedet. Trotz dieser vielfach ambitionierten Vorgaben und ansteigender installierter Kapazität von erneuerbaren Energien, treten Hindernisse bei der Umsetzung der politischen Ziele zu Tage und deren Erreichen wird gefährdet. Vielfältige Gründe für diese Schwierigkeiten konnten bisher identifiziert werden. Um erfolgreich die Diffusion von erneuerbaren Energietechnologien voranzutreiben und die politischen Zielvorgaben zu erfüllen, müssen die bekannten Hindernisse adressiert und Lösungen gefunden werden. Planungs- und Genehmigungsprozesse als Teil der Entscheidung über die Zulassung erneuerbarer Energieprojekte sind ein Faktor für die erfolgreiche Diffusion dieser neuen Technologien. Ein Element von Planung und Genehmigung sind oftmals Umweltprüfungen. Diese erfordern die Ermittlung und Berücksichtigung der Auswirkungen von erneuerbaren Energieprojekten auf die Umwelt. Das Ziel diese Dissertation ist die Ableitung von Hypothesen zur Rolle von Umweltprüfungen bei der Diffusion von erneuerbaren Energien und zur Notwendigkeit von Innovation bzw. Adaption dieses Instruments. Dieses Ziel wird erreicht durch die Analyse von gesetzlichen Vorgaben sowie der Praxis von Umweltprüfungen im Bereich von erneuerbaren Energien. Dazu werden zwei Fallbeispiele, die Vereinigten Staaten von Amerika sowie Deutschland, untersucht und verglichen. Grundsätzlich kann die Schlussfolgerung gezogen werden, dass Umweltprüfungen in bestimmten Aspekten verändert werden müssen, um den besonderen Herausforderungen bei der Diffusion von erneuerbaren Energien gerecht zu werden. Einige Bereiche der gesetzlichen Vorgaben sowie der Praxis von Umweltprüfungen stellen derzeit Hindernisse dar. Als ein Feld für zukünftige Forschung wird die Charakterisierung sowie empirischer Validierung der Rolle von Umweltprüfungen bei der Diffusion von erneuerbaren Energietechnologien gesehen. Weiterhin ist es nötig, die Prozesse, durch die eine Veränderung von rechtlichen Grundlagen sowie der Praxis von Umweltprüfung erreicht werden können, besser zu verstehen. Dabei ist es von besonderem Interesse zu analysieren, welche Rolle länderübergreifendes Lernen und der Transfer von Erfahrungen haben. The worldwide generation of energy from renewable resources such as wind, sun, biomass, water or ground heat, is constantly growing. Numerous countries have adopted renewable energy goals, often as part of their policies on fighting climate change. However, despite ambitious policy goals and increasing numbers in installed capacity, difficulties in the diffusion of renewable energy technologies occur and are jeopardizing the achievement of the targets. Several aspects have been identified to account for these difficulties in renewable energy diffusion. In order to successfully realize the diffusion of renewable energy technologies and to reach the goals for their future contribution to energy generation, the existing hindrances need to be addressed and solved. Planning and permitting, as the relevant decision-making processes, are one element of successful siting and deployment of renewable energy. Part of these planning and permitting processes often are environmental assessments (EA) requiring the consideration of the effects and impacts of the proposed renewable energy projects on the environment. The goal of this PhD thesis is the generation of hypotheses on the role of EA in the diffusion of renewable energy technologies, and on the need for innovation/adaptation of EA to fit the innovation system of renewable energy technology diffusion. This goal will be pursuit by the analysis of EA systems and EA practice related to renewable energy diffusion. Two cases will be analyzed and compared, namely the United States of America and Germany. In general, the conclusion can be drawn that EA for renewable energy diffusion needs to be improved in certain aspects in order to be able to meet the special requirements of this energy system. Some elements in EA legislation and practice pose certain problems in renewable energy diffusion. One field for further research would be the characterization of the role of environmental EA in renewable energy technology diffusion and its validation by qualitative means. Furthermore, in order to achieve the necessary changes of EA, it is important to enhance the understanding of the processes of change of this instrument. In particular, how cross-national policy learning and transfer of experiences impact the occurrence of such changes needs to be further studied.

Energy optimization is an increasingly important aspect of today’s high-performance computing applications. In particular, dynamic voltage and frequency scaling (DVFS) has become a widely adopted solution to balance performance and energy consumption, and hardware vendors provide management libraries that allow the programmer to change both memory and core frequencies manually to minimize energy consumption while maximizing performance. This article focuses on modeling the energy consumption and speedup of GPU applications while using different frequency configurations. The task is not straightforward, because of the large set of possible and uniformly distributed configurations and because of the multi-objective nature of the problem, which minimizes energy consumption and maximizes performance. This article proposes a machine learning-based method to predict the best core and memory frequency configurations on GPUs for an input OpenCL kernel. The method is based on two models for speedup and normalized energy predictions over the default frequency configuration. Those are later combined into a multi-objective approach that predicts a Pareto-set of frequency configurations. Results show that our approach is very accurate at predicting extema and the Pareto set, and finds frequency configurations that dominate the default configuration in either energy or performance.

We present a highly efficient monolithic perovskite/silicon tandem solar cell and analyze the tandem performance as a function of photocurrent mismatch with important implications for future device and energy yield optimizations.

The successful transition to a low-carbon economy hinges on innovative solutions and collaborative action on a global scale. Sustainable entrepreneurship is thereby recognized as a key driver in the creation and transformation of ecologically and socially sustainable economic systems. The purpose of this article is to contribute to this topic by understanding commercialization barriers for strong sustainability-oriented new technology ventures and to derive recommendations to overcome them. A qualitative multilevel approach is applied to identify barriers and drivers within the internal dynamic capabilities of the organization and within the organization’s external stakeholders. A model of barriers has been developed based on semi-structured interviews with new carbon dioxide utilization ventures and associated industry players in Canada, the USA, and the European Economic Area. Resulting recommendations to facilitate the (re-)design of a dedicated support system are proposed on four levels: (a) actors, (b) resources, (c) institutional settings, and (d) the coordination of the support system. Eine Korrektur zu diesem Artikel wurde publiziert in Front. Energy Res., 24 April 2018 | https://doi.org/10.3389/fenrg.2018.00031 A correction to this article has been published in Front. Energy Res., 24 April 2018 | https://doi.org/10.3389/fenrg.2018.00031

Demand response is a viable concept to deal with and benefit from fluctuating electricity prices and is of growing interest to the electrochemical industry. To assess the flexibility potential of such processes, a generic, interdisciplinary methodology is required. We propose such a methodology, in which the electrochemical fundamentals and the theoretical potential are determined first by analyzing strengths, weaknesses, opportunities, and threats. Afterward, experiments are conducted to determine selectivity and yield under varying loads and to assess the additional long-term costs associated with flexible operation. An industrial-scale electrochemical process is assessed regarding its technical, economic, and practical potential. The required steps include a flow sheet analysis, the formulation and solution of a simplified model for operation scheduling under various business options, and a dynamic optimization based on rigorous, dynamic process models. We apply the methodology to three electrochemical processes of different technology readiness levels—the syntheses of hydrogen peroxide, adiponitrile, and 1,2-dichloroethane via chloralkali electrolysis—to illustrate the individual steps of the proposed methodology.