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  • English
    Authors: 
    Seus, Sarah; Bührer, Susanne;
    Country: Germany

    This article is based on the evaluation of the German research funding programme ""FONA - Forschung für Nachhaltigkeit"" (Research for Sustainability.) It reflects upon the methodological challenges confronting the evaluation. These challenges result from the specific objectives and design of the FONA programme (a strategic portfolio of heterogenious interventions). FONA's ambition is to fund activities under the emerging field of 'sustainability research'. The core characteristics of sustainability research are: interdisciplinary and trans-disciplinary research processes; orientation towards transferring the research results (into society) and the interdependency with a wider system and global perspective.

  • Publication . Article . Other literature type . 2015
    Open Access English
    Authors: 
    Köhring, Michael; Böttger, Stefan; Willer, Ulrike; Schade, Wolfgang;
    Country: Germany

    it was designed to work as standalone device and was tested in a biogas plant for several weeks. Gas concentration dependent measurements show a precision better than 1% in a range between 40% and 60% target gas concentration for both sensors. Concentration dependent measurements with different background gases show a considerable decrease in cross sensitivity against the major components of biogas in direct comparison to common absorption based sensors. A new sensor for methane and carbon dioxide concentration measurements in biogas plants is presented. LEDs in the mid infrared spectral region are implemented as low cost light source. The combination of quartz-enhanced photoacoustic spectroscopy with an absorption path leads to a sensor setup suitable for the harsh application environment. The sensor system contains an electronics unit and the two gas sensors

  • Open Access
    Authors: 
    Eduard Wagner; Stephan Benecke; Janis Winzer; Nils F. Nissen; Klaus-D. Lang;
    Publisher: Elsevier BV
    Country: Germany

    Abstract Engineers are confronted with difficulties when it comes to the inclusion of sustainability aspects into the design process of electronic devices. Due to the specific nature and complexity of material composition, process flows and data availability there is a need for electronics-specific methodologies for environmental assessment. These need to allow for easy adaptation in all stages of the design process thus leading to a rapid identification of critical hotspots in system design. To fulfil this demand, indicators available for product-level assessment are evaluated with regard to environmental impact category coverage, practicability and significance for selected application fields of electronics. Case studies on sensor nodes and lighting products are used to show the application of indicator sets in industrial settings. As an outcome, indicator sets are identified that support the designer in keeping track of the overall sustainability of electronic products.

  • Publication . Article . Other literature type . 1991
    Closed Access English
    Authors: 
    Christine Dehm; Josef Gyulai; Heiner Ryssel;
    Country: Germany

    Abstract In this study, TiSi 2 contacts were fabricated using self-aligned silicidation technology by ion-beam mixing with germanium. The implantation energy for the mixing process was optimized by comparing Monte-Carlo simulations with sputtering neutral mass spectroscopy (SNMS) results. Shallow p + n junctions of 150 nm depth could be formed by 13 keV boron implantation in silicided germanium amorphized silicon substrates. For germanium amorphization, three implantation energies were chosen to cause an overlap between interstitial-rich areas of low energy implantation with vacancy-rich regions of subsequent high energy implantations. Using this triple germanium amorphization, end-of-range defect concentrations could be appreciable reduced compared to convential substrate amorphization, leading also to improved electrical characteristics. By triple germanium amorphization and 13 keV boron implantation low leakage currents of 10 nA and an ideality factor of 1.08 could be achieved.

  • Open Access English
    Authors: 
    Arens, M.; Worrell, E.; Energy, Resources & Technological Change; Energy and Resources;
    Countries: Netherlands, Germany

    We try to understand the role of technological change and diffusion of energy efficient technologies in order to explain the trend of energy intensity developments in the German steel industry. We selected six key energy efficient technologies and collected data to derive their diffusion since their introduction in Germany. Since all technologies have been applied in Germany for more than 30 years we would expect complete diffusion. We found complete diffusion only for basic oxygen furnaces and continuous casting. Newer technologies (i.e. basic oxygen furnace gas recovery, top pressure recovery turbine, coke dry quenching and pulverized coal injection) diffused quicker in the initial phase but then diffusion slowed down. Key improvements in energy efficiency are due to electric arc furnaces (24%), basic oxygen furnaces (12%), and continuous casting (6%) between 1958 and 2012. The contribution of top pressure recovery turbines, pulverized coal injection and basic oxygen furnaces gas recovery accounts in total of about 3%. If the selected technologies were diffused completely, the future energy consumption could be reduced by 4.5% compared to 2012. Our findings suggest that our selection of six technologies is the key driver for energy intensity developments within the German steel industry between 1958 and 2012.

  • Publication . Other literature type . Article . 2011
    Closed Access English
    Authors: 
    Lothar Kroll; P. Blau; Markus Wabner; U. Frieß; J. Eulitz; M. Klärner;
    Country: Germany

    Abstract The increasing demand for machine tools and production systems to be more energy-efficient poses new challenges for machine developers. The paper discusses the general influence of lightweight design approaches on energy efficiency in machine tools and restrictions on the maximum mass reduction for structural components. As a central aspect different quantitative consequences of energy consumption aspects regarding lightweight design are discussed in detail, considering direct and indirect effects of mass reduction on the energy efficiency. Conclusive investigations of the theoretical aspects are realized by an example component for different lightweight design approaches.

  • Publication . Article . Other literature type . 2007
    Closed Access
    Authors: 
    Ernst, B.; Oakleaf, B.; Ahlstrom, M.L.; Lange, M.; Moehrlen, C.; Lange, B.; Focken, U.; Rohrig, K.;
    Publisher: Institute of Electrical and Electronics Engineers (IEEE)
    Country: Germany

    Due to increasing wind power penetration, the need for and usage of wind power prediction systems have increased. At the same time, much research has been done in this field, which has led to a significant increase in the prediction accuracy recently. With many ongoing research programs in the field of numerical weather prediction (NWP), as well as in the power output prediction models (transforming wind speed into electrical power output), one can expect further improvements in the future. For the time being, three measures are taken as best practices to reduce prediction errors: Combinations of different models can be done with power output forecast models as well as with NWP models (multimodel and multischeme approaches). Reductions in RMSE of up to 20% were shown with intelligent combinations. As expected, a shorter forecast horizon leads to lower prediction errors. However, the organization of the electricity market as well as the conventional generation pool has a large influence on the needed forecast horizon. The forecast error depends on the number of wind turbines and wind farms and their geographical spread. In Germany, typical forecast errors for representative wind farm forecasts are 10-15% RMSE of installed power, while the error for the control areas calculated from these representative wind farms is typically 6-7% and that for the whole of Germany only 5-6%. Whenever possible, aggregating wind power over a large area should be performed as it leads to significant reduction of forecast errors as well as short-term fluctuations. a large area should be performed as it leads to significant reduction of forecast errors as well as short-term fluctuations.

  • Publication . Article . Other literature type . 2013
    Closed Access English
    Authors: 
    Friedemann D. Heinz; Paul Gundel; Wilhelm Warta; Martin C. Schubert;
    Country: Germany

    A quantitative doping density mapping technique for silicon samples with micrometer spatial resolution is presented. Being based on confocal microphotoluminescence spectroscopy, the technique allows for detailed quantitative analyses on the doping concentration of microscopic technological structures in silicon solar cells. The confocal microscope setup enables laser illumination with micrometer-sized focus and fast low-noise detection of the emitted luminescent radiation which depends on doping and free excess carrier density. The doping density is determined by calibrating the depth-dependent luminescent radiation with results from 2-D simulations of the carrier density. The high-resolution method is demonstrated on a state-of-the-art doping structure for back contact solar cells, where small deviations in the doping homogeneity can be detected. This proves the potential of the proposed technique to enhance the processing of doping microstructures and to strengthen the understanding of their physical properties.

  • Publication . Article . Other literature type . 2020
    Open Access
    Authors: 
    Dazhi Yang; Stefano Alessandrini; J. Antonanzas; F. Antonanzas-Torres; Viorel Badescu; Hans Georg Beyer; Robert Blaga; John Boland; Jamie M. Bright; Carlos F.M. Coimbra; +23 more
    Publisher: eScholarship, University of California
    Countries: United States, France, Germany, Germany, Australia

    The field of energy forecasting has attracted many researchers from different fields (e.g., meteorology, data sciences, mechanical or electrical engineering) over the last decade. Solar forecasting is a fast-growing subdomain of energy forecasting. Despite several previous attempts, the methods and measures used for verification of deterministic (also known as single-valued or point) solar forecasts are still far from being standardized, making forecast analysis and comparison difficult. To analyze and compare solar forecasts, the well-established Murphy–Winkler framework for distribution-oriented forecast verification is recommended as a standard practice. This framework examines aspects of forecast quality, such as reliability, resolution, association, or discrimination, and analyzes the joint distribution of forecasts and observations, which contains all time-independent information relevant to verification. To verify forecasts, one can use any graphical display or mathematical/statistical measure to provide insights and summarize the aspects of forecast quality. The majority of graphical methods and accuracy measures known to solar forecasters are specific methods under this general framework. Additionally, measuring the overall skillfulness of forecasters is also of general interest. The use of the root mean square error (RMSE) skill score based on the optimal convex combination of climatology and persistence methods is highly recommended. By standardizing the accuracy measure and reference forecasting method, the RMSE skill score allows—with appropriate caveats—comparison of forecasts made using different models, across different locations and time periods. Refereed/Peer-reviewed

  • Closed Access English
    Authors: 
    Christian Lutz; Bernd Meyer; Carsten Nathani; Joachim Schleich;
    Country: Germany

    Abstract The paper starts from the observation that innovation and technical progress are only portrayed superficially in the predominant environmental economic top-down models, and that the assumption of perfect factor substitution does not correctly mirror actual production conditions in many energy-intensive production sectors. Bottom-up models, on the other hand, neglect macroeconomic interdependencies between the modelled sector and the general economy. This paper presents a new modelling approach: in an integrated bottom-up/top-down approach based on the example of crude steel production in Germany, it is demonstrated how technological progress can be portrayed as process-related and policy-induced and how the technology choice between limitational processes can be explicitly modelled and implemented in the econometric input–output model PANTA RHEI. The new modelling approach presented permits a process-specific analysis of the impacts of changed frame conditions, the effects of which on the choice of technology, on the one hand, and the technological progress on the other, can be described endogenous to the model. These features are demonstrated in a CO2 tax simulation. Results show that policy-induced technological change is—besides a switch in production processes—the major source of CO2 reduction for the steel sector.

Advanced search in Research products
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
The following results are related to Energy Research. Are you interested to view more results? Visit OpenAIRE - Explore.
4,968 Research products, page 1 of 497
  • English
    Authors: 
    Seus, Sarah; Bührer, Susanne;
    Country: Germany

    This article is based on the evaluation of the German research funding programme ""FONA - Forschung für Nachhaltigkeit"" (Research for Sustainability.) It reflects upon the methodological challenges confronting the evaluation. These challenges result from the specific objectives and design of the FONA programme (a strategic portfolio of heterogenious interventions). FONA's ambition is to fund activities under the emerging field of 'sustainability research'. The core characteristics of sustainability research are: interdisciplinary and trans-disciplinary research processes; orientation towards transferring the research results (into society) and the interdependency with a wider system and global perspective.

  • Publication . Article . Other literature type . 2015
    Open Access English
    Authors: 
    Köhring, Michael; Böttger, Stefan; Willer, Ulrike; Schade, Wolfgang;
    Country: Germany

    it was designed to work as standalone device and was tested in a biogas plant for several weeks. Gas concentration dependent measurements show a precision better than 1% in a range between 40% and 60% target gas concentration for both sensors. Concentration dependent measurements with different background gases show a considerable decrease in cross sensitivity against the major components of biogas in direct comparison to common absorption based sensors. A new sensor for methane and carbon dioxide concentration measurements in biogas plants is presented. LEDs in the mid infrared spectral region are implemented as low cost light source. The combination of quartz-enhanced photoacoustic spectroscopy with an absorption path leads to a sensor setup suitable for the harsh application environment. The sensor system contains an electronics unit and the two gas sensors

  • Open Access
    Authors: 
    Eduard Wagner; Stephan Benecke; Janis Winzer; Nils F. Nissen; Klaus-D. Lang;
    Publisher: Elsevier BV
    Country: Germany

    Abstract Engineers are confronted with difficulties when it comes to the inclusion of sustainability aspects into the design process of electronic devices. Due to the specific nature and complexity of material composition, process flows and data availability there is a need for electronics-specific methodologies for environmental assessment. These need to allow for easy adaptation in all stages of the design process thus leading to a rapid identification of critical hotspots in system design. To fulfil this demand, indicators available for product-level assessment are evaluated with regard to environmental impact category coverage, practicability and significance for selected application fields of electronics. Case studies on sensor nodes and lighting products are used to show the application of indicator sets in industrial settings. As an outcome, indicator sets are identified that support the designer in keeping track of the overall sustainability of electronic products.

  • Publication . Article . Other literature type . 1991
    Closed Access English
    Authors: 
    Christine Dehm; Josef Gyulai; Heiner Ryssel;
    Country: Germany

    Abstract In this study, TiSi 2 contacts were fabricated using self-aligned silicidation technology by ion-beam mixing with germanium. The implantation energy for the mixing process was optimized by comparing Monte-Carlo simulations with sputtering neutral mass spectroscopy (SNMS) results. Shallow p + n junctions of 150 nm depth could be formed by 13 keV boron implantation in silicided germanium amorphized silicon substrates. For germanium amorphization, three implantation energies were chosen to cause an overlap between interstitial-rich areas of low energy implantation with vacancy-rich regions of subsequent high energy implantations. Using this triple germanium amorphization, end-of-range defect concentrations could be appreciable reduced compared to convential substrate amorphization, leading also to improved electrical characteristics. By triple germanium amorphization and 13 keV boron implantation low leakage currents of 10 nA and an ideality factor of 1.08 could be achieved.

  • Open Access English
    Authors: 
    Arens, M.; Worrell, E.; Energy, Resources & Technological Change; Energy and Resources;
    Countries: Netherlands, Germany

    We try to understand the role of technological change and diffusion of energy efficient technologies in order to explain the trend of energy intensity developments in the German steel industry. We selected six key energy efficient technologies and collected data to derive their diffusion since their introduction in Germany. Since all technologies have been applied in Germany for more than 30 years we would expect complete diffusion. We found complete diffusion only for basic oxygen furnaces and continuous casting. Newer technologies (i.e. basic oxygen furnace gas recovery, top pressure recovery turbine, coke dry quenching and pulverized coal injection) diffused quicker in the initial phase but then diffusion slowed down. Key improvements in energy efficiency are due to electric arc furnaces (24%), basic oxygen furnaces (12%), and continuous casting (6%) between 1958 and 2012. The contribution of top pressure recovery turbines, pulverized coal injection and basic oxygen furnaces gas recovery accounts in total of about 3%. If the selected technologies were diffused completely, the future energy consumption could be reduced by 4.5% compared to 2012. Our findings suggest that our selection of six technologies is the key driver for energy intensity developments within the German steel industry between 1958 and 2012.

  • Publication . Other literature type . Article . 2011
    Closed Access English
    Authors: 
    Lothar Kroll; P. Blau; Markus Wabner; U. Frieß; J. Eulitz; M. Klärner;
    Country: Germany

    Abstract The increasing demand for machine tools and production systems to be more energy-efficient poses new challenges for machine developers. The paper discusses the general influence of lightweight design approaches on energy efficiency in machine tools and restrictions on the maximum mass reduction for structural components. As a central aspect different quantitative consequences of energy consumption aspects regarding lightweight design are discussed in detail, considering direct and indirect effects of mass reduction on the energy efficiency. Conclusive investigations of the theoretical aspects are realized by an example component for different lightweight design approaches.

  • Publication . Article . Other literature type . 2007
    Closed Access
    Authors: 
    Ernst, B.; Oakleaf, B.; Ahlstrom, M.L.; Lange, M.; Moehrlen, C.; Lange, B.; Focken, U.; Rohrig, K.;
    Publisher: Institute of Electrical and Electronics Engineers (IEEE)
    Country: Germany

    Due to increasing wind power penetration, the need for and usage of wind power prediction systems have increased. At the same time, much research has been done in this field, which has led to a significant increase in the prediction accuracy recently. With many ongoing research programs in the field of numerical weather prediction (NWP), as well as in the power output prediction models (transforming wind speed into electrical power output), one can expect further improvements in the future. For the time being, three measures are taken as best practices to reduce prediction errors: Combinations of different models can be done with power output forecast models as well as with NWP models (multimodel and multischeme approaches). Reductions in RMSE of up to 20% were shown with intelligent combinations. As expected, a shorter forecast horizon leads to lower prediction errors. However, the organization of the electricity market as well as the conventional generation pool has a large influence on the needed forecast horizon. The forecast error depends on the number of wind turbines and wind farms and their geographical spread. In Germany, typical forecast errors for representative wind farm forecasts are 10-15% RMSE of installed power, while the error for the control areas calculated from these representative wind farms is typically 6-7% and that for the whole of Germany only 5-6%. Whenever possible, aggregating wind power over a large area should be performed as it leads to significant reduction of forecast errors as well as short-term fluctuations. a large area should be performed as it leads to significant reduction of forecast errors as well as short-term fluctuations.

  • Publication . Article . Other literature type . 2013
    Closed Access English
    Authors: 
    Friedemann D. Heinz; Paul Gundel; Wilhelm Warta; Martin C. Schubert;
    Country: Germany

    A quantitative doping density mapping technique for silicon samples with micrometer spatial resolution is presented. Being based on confocal microphotoluminescence spectroscopy, the technique allows for detailed quantitative analyses on the doping concentration of microscopic technological structures in silicon solar cells. The confocal microscope setup enables laser illumination with micrometer-sized focus and fast low-noise detection of the emitted luminescent radiation which depends on doping and free excess carrier density. The doping density is determined by calibrating the depth-dependent luminescent radiation with results from 2-D simulations of the carrier density. The high-resolution method is demonstrated on a state-of-the-art doping structure for back contact solar cells, where small deviations in the doping homogeneity can be detected. This proves the potential of the proposed technique to enhance the processing of doping microstructures and to strengthen the understanding of their physical properties.

  • Publication . Article . Other literature type . 2020
    Open Access
    Authors: 
    Dazhi Yang; Stefano Alessandrini; J. Antonanzas; F. Antonanzas-Torres; Viorel Badescu; Hans Georg Beyer; Robert Blaga; John Boland; Jamie M. Bright; Carlos F.M. Coimbra; +23 more
    Publisher: eScholarship, University of California
    Countries: United States, France, Germany, Germany, Australia

    The field of energy forecasting has attracted many researchers from different fields (e.g., meteorology, data sciences, mechanical or electrical engineering) over the last decade. Solar forecasting is a fast-growing subdomain of energy forecasting. Despite several previous attempts, the methods and measures used for verification of deterministic (also known as single-valued or point) solar forecasts are still far from being standardized, making forecast analysis and comparison difficult. To analyze and compare solar forecasts, the well-established Murphy–Winkler framework for distribution-oriented forecast verification is recommended as a standard practice. This framework examines aspects of forecast quality, such as reliability, resolution, association, or discrimination, and analyzes the joint distribution of forecasts and observations, which contains all time-independent information relevant to verification. To verify forecasts, one can use any graphical display or mathematical/statistical measure to provide insights and summarize the aspects of forecast quality. The majority of graphical methods and accuracy measures known to solar forecasters are specific methods under this general framework. Additionally, measuring the overall skillfulness of forecasters is also of general interest. The use of the root mean square error (RMSE) skill score based on the optimal convex combination of climatology and persistence methods is highly recommended. By standardizing the accuracy measure and reference forecasting method, the RMSE skill score allows—with appropriate caveats—comparison of forecasts made using different models, across different locations and time periods. Refereed/Peer-reviewed

  • Closed Access English
    Authors: 
    Christian Lutz; Bernd Meyer; Carsten Nathani; Joachim Schleich;
    Country: Germany

    Abstract The paper starts from the observation that innovation and technical progress are only portrayed superficially in the predominant environmental economic top-down models, and that the assumption of perfect factor substitution does not correctly mirror actual production conditions in many energy-intensive production sectors. Bottom-up models, on the other hand, neglect macroeconomic interdependencies between the modelled sector and the general economy. This paper presents a new modelling approach: in an integrated bottom-up/top-down approach based on the example of crude steel production in Germany, it is demonstrated how technological progress can be portrayed as process-related and policy-induced and how the technology choice between limitational processes can be explicitly modelled and implemented in the econometric input–output model PANTA RHEI. The new modelling approach presented permits a process-specific analysis of the impacts of changed frame conditions, the effects of which on the choice of technology, on the one hand, and the technological progress on the other, can be described endogenous to the model. These features are demonstrated in a CO2 tax simulation. Results show that policy-induced technological change is—besides a switch in production processes—the major source of CO2 reduction for the steel sector.