@inproceedings{RammEhrenwirthSchrag2019, author = {Ramm, Tobias and Ehrenwirth, Mathias and Schrag, Tobias}, title = {Modelling of the central heating station within a district heating system with variable temperatures}, booktitle = {Proceedings of the 13th International Modelica Conference}, editor = {Haumer, Anton}, publisher = {Modelica Association and Link{\"o}ping University Electronic Press}, address = {Link{\"o}ping}, isbn = {978-91-7685-122-7}, issn = {1650-3686}, doi = {http://dx.doi.org/10.3384/ecp19157567}, pages = {567 -- 576}, year = {2019}, language = {en} } @inproceedings{SchragEhrenwirthRammetal.2020, author = {Schrag, Tobias and Ehrenwirth, Mathias and Ramm, Tobias and Vannahme, Anna and Trinkl, Christoph}, title = {Solar energy use in district heating networks}, booktitle = {ICREEC 2019: Proceedings of the 1st International Conference on Renewable Energy and Energy Conversion}, editor = {Belasri, Ahmed and Beldjilali, Sid Ahmed}, publisher = {Springer}, address = {Singapur}, isbn = {978-981-15-5443-8}, issn = {2352-2534}, doi = {https://doi.org/10.1007/978-981-15-5444-5_1}, pages = {3 -- 10}, year = {2020}, language = {en} } @article{SlonskiSchrag2019, author = {Slonski, Matthias and Schrag, Tobias}, title = {Linear optimisation of a settlement towards the energy-plus house standard}, volume = {12}, pages = {210}, journal = {Energies}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en12020210}, year = {2019}, abstract = {Future buildings will use technologies that are either well-known, innovative, or a combination thereof in order to be environmentally friendly and feasible at the same time. To evaluate and compare such systems through simulation, adaptive tools need to be available. This paper describes a conceived method for planning quarters and settlements. The novelty of this work emerges from the combination of a building simulation with a linear economic optimisation of the energy system, to achieve the energy-plus house standard for a settlement. Furthermore, the tools applied are adaptive or open source. In this article, a hypothetical basic example is given for a predefined idealised settlement, which consists of 132 single-family houses of one building type. The hourly demand for electrical energy and heat is established for three energy-efficiency classes for the building type with a dynamic simulation in MATLAB/SIMULINK using the CARNOT toolbox. This toolbox is also used to calculate the specific electrical energy production by photovoltaics. The components for the energy system of the settlement are implemented in the open source linear optimisation tool URBS. An economic optimum for the energy system of the settlement is found for each of the energy efficiency classes for an accumulated energy demand of the buildings. In this way, a lossless energy hub between the buildings is assumed. The results of the conducted simulations indicate that the optimal ratio of air/water to ground/water heat pumps shifts towards air/water heat pumps with more energy efficient houses. This is due to the lower specific investment costs, which outweigh the operational costs when less energy is required. The lowest costs for the entire energy system are for the one with the most energy efficient settlement. This is the case, as the costs for the higher energy standard of the buildings are not considered in the calculations. The behaviour of the optimisation is tested and discussed through a sensitivity analysis for one efficiency class. By presenting this simple, comprehensible example, an impression of the possible applications for this methodology is conveyed.}, language = {en} } @inproceedings{VannahmeRammEhrenwirthetal.2019, author = {Vannahme, Anna and Ramm, Tobias and Ehrenwirth, Mathias and Schrag, Tobias}, title = {Comparison of a usual heat-transfer-station with a hydraulic modified version under the aspect of exergy saving}, booktitle = {Proceedings of the 13th International Modelica Conference}, editor = {Haumer, Anton}, publisher = {Link{\"o}ping University Electronic Press}, address = {Link{\"o}ping}, isbn = {978-91-7685-122-7}, issn = {1650-3686}, doi = {http://dx.doi.org/10.3384/ecp19157647}, pages = {647 -- 654}, year = {2019}, language = {en} } @article{MehtaMingalevaZoerneretal.2022, author = {Mehta, Kedar and Mingaleva, Ekaterina and Z{\"o}rner, Wilfried and Degembaeva, Nadira and Baibagyshov, Ermek}, title = {Comprehensive analysis of the energy legislative framework of Kyrgyzstan}, volume = {2022}, pages = {100013}, journal = {Cleaner Energy Systems}, subtitle = {Investigation to develop a roadmap of Kyrgyz renewable energy sector}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2772-7831}, doi = {https://doi.org/10.1016/j.cles.2022.100013}, year = {2022}, abstract = {Kyrgyzstan - a Central Asian country - faces a high degree of energy insecurity. Especially the Kyrgyz power sector suffers from outdated infrastructure and is not capable of fulfilling the growing and fluctuating inter-seasonal energy demand. On the contrary, the country is endowed with an abundant amount of renewable energies, which can significantly contribute to bringing stability to the energy sector. The current energy policy is considered as one of the key barriers to the developing the renewable energy sector in Kyrgyzstan. Hence, there is an immediate need to evaluate the formulated energy policy to investigate gaps and uncertainties. In response to that, the presented study is the first attempt that provides an in-depth assessment of Kyrgyzstan's current energy legislative framework. It determines the primary mechanisms for the operation and conduction of renewable energy sources in terms of legal and economic aspects. Furthermore, it provides detailed insight into the current Feed-in tariff calculation methodology and scrutinizes the special provisions for private investors. Based on the in-depth assessment, the article recapitulates the shortfall in the existing energy policies. The article found that there is huge potential available for the renewable energy market. To unlock that, the presented article emahsised on synergestic policy making approach to overcome barriers and expand the Kyrgyz renewable energy sector. The article further showcased how the improvements in the regulatory framework would raise the interest of the private investors / local energy players to promote the installation of renewable energy technologies over the county.}, language = {en} } @article{MehtaEhrenwirthTrinkletal.2022, author = {Mehta, Kedar and Ehrenwirth, Mathias and Trinkl, Christoph and Z{\"o}rner, Wilfried}, title = {Mapping Potential for Improving Rural Energy Services in Kyrgyzstan: Factors for Achieving Sustainable Development Goals in the Community Context}, volume = {3}, journal = {World}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2673-4060}, doi = {https://doi.org/10.3390/world3030032}, pages = {586 -- 606}, year = {2022}, abstract = {Energy is a pivotal element for overall development. Therefore, affordable and clean energy for all (Sustainable Development Goal 7) is one of the important elements. Despite a suitable approach, Kyrgyzstan lags behind to achieve its Sustainable Development Goals by 2030. Improving access to energy can significantly impact the progress of many other sustainable development targets. However, access to reliable, sustainable, and adequate energy is a crucial task in rural Kyrgyzstan. Taking into consideration the energy situation and the importance of the availability of energy services, the overarching aim of the presented article is to map the potential of improving rural energy services to foster overall sustainable development goals. The article presents the most relevant information about rural energy usage behaviour based on three primary pillars: energy demand, energy carrier, and energy sources. In addition, the presented research article synthesises the key driving factors which have a direct or indirect impact on the energy services in rural areas. The summarised data displays a deep insight into a variety of complex and dynamic household energy consumption patterns. The article provides a potential solution nexus to foster improved energy services in rural Kyrgyzstan and therefore to foster the overall sustainable development in Kyrgyzstan. The findings of the article help to formulate a strategy to design rural energy services for policy makers and stockholders.}, language = {en} } @article{MehtaZoernerGreenough2022, author = {Mehta, Kedar and Z{\"o}rner, Wilfried and Greenough, Richard}, title = {Residential Building Construction Techniques and the Potential for Energy Efficiency in Central Asia: Example from High-Altitude Rural Settlement in Kyrgyzstan}, volume = {15}, pages = {8869}, journal = {Energies}, number = {23}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en15238869}, year = {2022}, abstract = {Building construction in rural Kyrgyzstan is heavily dominated by earthen buildings. Old and inappropriate residential building structures contribute significantly to high domestic space heating energy consumption. Therefore, it is necessary to understand the relevant building construction techniques. However, the scant information on Kyrgyz building techniques, especially for high-altitude rural settlements, was the prime motivation to perform the presented study. The key objective of the study is to investigate residential building construction techniques in high-altitude rural Kyrgyzstan, and this was to be achieved by house visits during field trips, literature review, and pilot interviews with local people. The analysis enabled the detailed identification of individual building envelopes as well as predominant building materials to be recorded. Based on the assessment, a housing profile was created that represents the typical characteristics of traditional rural Kyrgyz houses. Furthermore, the study demonstrates the potential for energy savings in rural Kyrgyz houses of 50-70\%. However, local conditions prevent people from making improvements to all domestic energy efficiency parameters simultaneously. Therefore, the study developed a 'sequential roadmap' to reduce domestic space heating demand in different phases based on simulation studies. Existing low-income rural Kyrgyz habitations can use the presented roadmap to reduce domestic space heating demand sequentially to overcome financial barriers and, therefore, contribute to establishing sustainable buildings in Kyrgyzstan. These results may be partially replicated in other Central Asian rural communities depending on their location and building characteristics.}, language = {en} } @article{StarkTrinklZoerneretal.2018, author = {Stark, Matthias and Trinkl, Christoph and Z{\"o}rner, Wilfried and Greenough, Richard}, title = {Methodological Evaluation of Storage Systems for Flexible Power Generation from Solid Biomass}, volume = {41}, journal = {Chemical Engineering \& Technology}, number = {11}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-4125}, doi = {https://doi.org/10.1002/ceat.201800099}, pages = {2168 -- 2176}, year = {2018}, language = {en} } @article{SelleneitStoecklHolzhammer2020, author = {Selleneit, Volker and St{\"o}ckl, Martin and Holzhammer, Uwe}, title = {System efficiency: methodology for rating of industrial utilities in electricity grids with a high share of variable renewable energies}, volume = {2020}, pages = {109969}, journal = {Renewable and Sustainable Energy Reviews}, subtitle = {a first approach}, number = {130}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1364-0321}, doi = {https://doi.org/10.1016/j.rser.2020.109969}, year = {2020}, language = {en} } @article{SelleneitStoecklPhilippetal.2019, author = {Selleneit, Volker and St{\"o}ckl, Martin and Philipp, Matthias and Mast, Tanja and Holzhammer, Uwe and Schlosser, Florian}, title = {System efficiency rating of industrial utilities in electricity grids with a high share of variable renewable energies}, volume = {2019}, journal = {Chemical Engineering Transactions}, number = {76}, publisher = {AIDIC}, address = {Mailand}, issn = {2283-9216}, doi = {https://doi.org/10.3303/CET1976163}, pages = {973 -- 978}, year = {2019}, language = {en} } @article{StoecklSelleneitPhilippetal.2019, author = {St{\"o}ckl, Martin and Selleneit, Volker and Philipp, Matthias and Holzhammer, Uwe}, title = {An approach to calculate electricity costs for the german industry for a system efficient design by combining energy efficiency and demand response}, volume = {2019}, journal = {Chemical Engineering Transactions}, number = {76}, publisher = {AIDIC}, address = {Mailand}, issn = {2283-9216}, doi = {https://doi.org/10.3303/CET1976191}, pages = {1141 -- 1146}, year = {2019}, language = {en} } @inproceedings{HuemmerMastKolleretal.2020, author = {H{\"u}mmer, Benedikt and Mast, Tanja and Koller, Maria and Holzhammer, Uwe}, title = {Smart Markets in Southern Germany: Key factors for profits of biogas plants}, booktitle = {2020 17th International Conference on the European Energy Market (EEM)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-6919-4}, doi = {https://doi.org/10.1109/EEM49802.2020.9221988}, year = {2020}, language = {en} } @techreport{EltropNagelHolzhammeretal.2020, author = {Eltrop, Ludger and Nagel, Sylvio and Holzhammer, Uwe and Mast, Tanja and Wachinger, Gisela}, title = {Schlussbericht zu Nr. 3.2 Verbundvorhaben „OptiSys"}, doi = {https://doi.org/10.2314/KXP:1738015386}, pages = {126}, year = {2020}, language = {de} } @techreport{HuemmerMastHolzhammeretal.2023, author = {H{\"u}mmer, Benedikt and Mast, Tanja and Holzhammer, Uwe and Vogler, Gilbert}, title = {Biogasanlagen als Akteur am Smart Market - Zus{\"a}tzliches Erl{\"o}spotential heben}, subtitle = {Gemeinsamer Abschlussbericht}, doi = {https://doi.org/10.2314/KXP:1879470640}, pages = {45}, year = {2023}, language = {de} } @inproceedings{MastHuemmerHolzhammer2021, author = {Mast, Tanja and H{\"u}mmer, Benedikt and Holzhammer, Uwe}, title = {Erl{\"o}spotential f{\"u}r Biogasanlagen an Smart Markets}, booktitle = {Tagungsunterlagen Zuk{\"u}nftige Stromnetze}, publisher = {Conexio GmbH}, address = {Pforzheim}, isbn = {978-3-948176-12-9}, doi = {https://www.zukunftsnetz.net/konferenz/tagungsbaende}, pages = {224 -- 245}, year = {2021}, language = {de} } @inproceedings{HuemmerMastHolzhammer2021, author = {H{\"u}mmer, Benedikt and Mast, Tanja and Holzhammer, Uwe}, title = {Einflussfaktoren auf das Erl{\"o}spotential von Biogasanlagen in Smart Markets}, booktitle = {Tagungsband 15. Rostocker Bioenergieforum}, editor = {Nelles, Michael}, publisher = {Universit{\"a}t Rostock}, address = {Rostock}, isbn = {978-3-86009-524-9}, doi = {https://doi.org/10.18453/rosdok_id00003024}, pages = {109 -- 118}, year = {2021}, language = {de} } @article{PhilippSchummSchlosseretal.2017, author = {Philipp, Matthias and Schumm, Gregor and Schlosser, Florian and Peesel, Ron-Hendrick and Holzhammer, Uwe}, title = {Grundsatzfragen der Abw{\"a}rmenutzung}, volume = {69}, journal = {BWK - Das Energie-Fachmagazin}, number = {4}, publisher = {VDI Fachmedien}, address = {D{\"u}sseldorf}, issn = {1618-193X}, url = {https://www.ingenieur.de/fachmedien/bwk/energieversorgung/grundsatzfragen-der-abwaermenutzung/}, pages = {36 -- 39}, year = {2017}, language = {de} } @article{BaderBrandmayrTrinkletal.2014, author = {Bader, Tobias and Brandmayr, Sebastian and Trinkl, Christoph and Z{\"o}rner, Wilfried and Hanby, Victor Ian}, title = {Climate Specific Design and Effectiveness of Solar DEC-systems}, volume = {2014}, journal = {Energy Procedia}, subtitle = {a Methodological Zoning Approach}, number = {48}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102}, doi = {https://doi.org/10.1016/j.egypro.2014.02.090}, pages = {778 -- 789}, year = {2014}, abstract = {The climate specific effectiveness of solar DEC-systems and relevant preferable adaptions of the system design have been so far predominantly analysed based on individual simulation for selected sites. In order to systematically deduce design-specific outline data for the application of the solar DEC-technology at climatically different sites a methodological zoning approach was further developed. A subsequent meteorological analysis for 17 sites mapping the world climate creates a transparent understanding on the activity of the specific system components. This results in a comprehension on the site-specific effectiveness of solar DEC-systems and provides insights on principally relevant and efficient system configurations.}, language = {en} } @article{ReiterBrandmayrTrinkletal.2014, author = {Reiter, Christoph and Brandmayr, Sebastian and Trinkl, Christoph and Z{\"o}rner, Wilfried and Hanby, Victor Ian}, title = {Performance Optimisation of Polymeric Collectors by Means of Dynamic Simulation and Sensitivity Analysis}, volume = {2014}, journal = {Energy Procedia}, number = {48}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102}, doi = {https://doi.org/10.1016/j.egypro.2014.02.023}, pages = {181 -- 191}, year = {2014}, abstract = {A dynamic flat-plate collector model for parametric sensitivity studies on polymer-based collector designs was developed. Validation using experimental results of conventional flat-plate collectors showed satisfying results especially regarding the calculation of individual part temperatures of a collector. The model was used to predict system efficiency as well as individual part temperatures in order to analyse a polymeric collector approach in comparison to a conventional collector. The simulation results showed that the fractional energy savings of systems with conventional flat-plate collectors cannot be reached with the analysed polymeric collector approach. Also the stagnation temperatures of more efficient approaches are too high for low-cost polymeric materials. The exemplary analysis of annual temperature loads of the backside insulation for different approaches proved the necessity of careful collector design aiming at temperature reduction for all individual collector parts.}, language = {en} } @inproceedings{RammHammelKlaerneretal.2017, author = {Ramm, Tobias and Hammel, Carolina and Kl{\"a}rner, Michael and Kruck, Alfons and Schrag, Tobias}, title = {Energy storage and integrated energy approach for district heating systems}, volume = {2017}, booktitle = {Energy Procedia}, number = {135}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102}, doi = {https://doi.org/10.1016/j.egypro.2017.09.515}, pages = {391 -- 397}, year = {2017}, abstract = {This paper deals with the potential of using the thermal storage capacities within local district heating systems to balance the low and medium voltage grids by the use of heat pumps (HP) and combined heat and power (CHP) plants. The state-of-the-ar of district heating systems as well as the coupling of the heat and power grid is discussed. The research work of the projec NATAR (local heating grids with lowered temperature as provider of balancing power) and the local heating grid of Dollnstein which serves as an use case, are further described. A first analysis of measured data of the district heating system indicates an optimisation potential regarding to the control strategy of the combined heat and power plant as well as the usage of the available thermal storage capacities.}, language = {en} } @article{TrinklZoernerHanby2009, author = {Trinkl, Christoph and Z{\"o}rner, Wilfried and Hanby, Victor Ian}, title = {Simulation study on a domestic solar/heat pump heating system incorporating latent and stratified thermal storage}, volume = {131}, pages = {041008}, journal = {Journal of Solar Energy Engineering}, number = {4}, publisher = {ASME}, address = {New York}, issn = {1528-8986}, doi = {https://doi.org/10.1115/1.3197845}, year = {2009}, language = {en} } @article{RiessBrandmayrZoerneretal.2014, author = {Riess, Hermann and Brandmayr, Sebastian and Z{\"o}rner, Wilfried and Greenough, Richard}, title = {Analysis of the mechanical behaviour of an all-round fully adhesive supported absorber}, volume = {2014}, journal = {Energy Procedia}, number = {48}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102}, doi = {https://doi.org/10.1016/j.egypro.2014.02.025}, pages = {201 -- 211}, year = {2014}, abstract = {This paper discusses the mechanical behaviour of an all-round fully adhesive supported absorber. Previous research is discussed and compared to the author's own results collected using both laboratory tests and simulation. The influence of the finite-element approach (i.e. geometrically linear or non-linear) was compared. The thermal deformation of a hyperstatic absorber was investigated. The relationship between thermal expansion and pressure change in a gas-filled collector is discussed.}, language = {en} } @article{MuellerBrandmayrZoerner2014, author = {M{\"u}ller, Holger and Brandmayr, Sebastian and Z{\"o}rner, Wilfried}, title = {Development of an evaluation methodology for the potential of solar-thermal energy use in the food industry}, volume = {214}, journal = {Energy Procedia}, number = {48}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102}, doi = {https://doi.org/10.1016/j.egypro.2014.02.135}, pages = {1194 -- 1201}, year = {2014}, abstract = {The research project 'Solar Heat in the Liquid Food Industry' (part of the FORETA Research Network) focused on the development and optimisation of low-temperature heating systems for the liquid food industry. Its main objectives are in energy efficiency, waste heat recovery and the feasibility of a solar-thermal process heating system. Based on the particular simulation results the overall solar-thermal potentials for German breweries and dairies were determined. In this connection a literature review indicated that most of the potential studies on solar-thermal energy use in the industry or related to specific industrial sectors are based on the total use of low-temperature heat. In opposition to these results, the available and mainly limited roof area was found to be a more important aspect for the solar-thermal potential. Hence, the development of a methodology for a site- specific analysis was necessary. The interconnection of only a few defined evaluation criteria resulted in a more realistic estimation of the potential for a solar-thermal heat supply.}, language = {en} } @article{HaslerHuberLeindeckeretal.2013, author = {Hasler, Ewald and Huber, Christian and Leindecker, Herbert C. and Schrag, Tobias and Stocker, Emanuel and Wartha, Christian}, title = {Bewertung unterschiedlicher Fassadenkonstruktionen unter Lebenszyklusaspekten mit einer Fallstudie B{\"u}rogeb{\"a}ude}, volume = {35}, journal = {Bauphysik}, number = {4}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {1437-0980}, doi = {https://doi.org/10.1002/bapi.201310072}, pages = {250 -- 256}, year = {2013}, language = {de} } @inproceedings{SaidiContiKarletal.2019, author = {Saidi, Abdessamad and Conti, Fosca and Karl, J{\"u}rgen and Goldbrunner, Markus}, title = {Biogastankstelle f{\"u}r die Landwirtschaft - Gegen{\"u}berstellende {\"o}konomische Bewertung unterschiedlicher Verfahren f{\"u}r die dezentrale partielle Biogasaufbereitung}, booktitle = {8. Statuskonferenz Bioenergie Reader}, editor = {Thr{\"a}n, Daniela and Pfeiffer, Diana}, publisher = {DBFZ Deutsches Biomasseforschungszentrum gemeinn{\"u}tzige GmbH}, address = {Leipzig}, isbn = {978-3-946629-27-6}, issn = {2698-6809}, url = {https://www.energetische-biomassenutzung.de/veranstaltungen/statuskonferenzen/8-statuskonferenz/programm}, pages = {78 -- 79}, year = {2019}, language = {de} } @inproceedings{ContiSaidiGoldbrunner2019, author = {Conti, Fosca and Saidi, Abdessamad and Goldbrunner, Markus}, title = {Verbesserung der Durchmischung in Biogasfermentern}, booktitle = {8. Statuskonferenz Bioenergie Reader}, editor = {Thr{\"a}n, Daniela and Pfeiffer, Diana}, publisher = {DBFZ Deutsches Biomasseforschungszentrum gemeinn{\"u}tzige GmbH}, address = {Leipzig}, isbn = {978-3-946629-27-6}, issn = {2698-6809}, url = {https://www.energetische-biomassenutzung.de/veranstaltungen/statuskonferenzen/8-statuskonferenz/programm}, pages = {105}, year = {2019}, language = {de} } @article{WiedemannContiSaidietal.2018, author = {Wiedemann, Leonhard and Conti, Fosca and Saidi, Abdessamad and Sonnleitner, Matthias and Goldbrunner, Markus}, title = {Modeling Mixing in Anaerobic Digesters with Computational Fluid Dynamics Validated by Experiments}, volume = {41}, journal = {Chemical Engineering \& Technology}, number = {11}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-4125}, doi = {https://doi.org/10.1002/ceat.201800083}, pages = {2101 -- 2110}, year = {2018}, language = {en} } @inproceedings{ContiWiedemannSaidietal.2018, author = {Conti, Fosca and Wiedemann, Leonhard and Saidi, Abdessamad and Sonnleitner, Matthias and Goldbrunner, Markus}, title = {Mixing of a Model Substrate in a Scale-down Laboratory Digester and Processing with a Computational Fluid Dynamics Model}, booktitle = {EUBCE 2018 Online Conference Proceedings}, publisher = {ETA s.r.l.}, address = {Florenz}, isbn = {978-88-89407-18-9}, issn = {2282-5819}, doi = {https://doi.org/10.5071/26thEUBCE2018-2CV.5.34}, pages = {811 -- 815}, year = {2018}, language = {en} } @article{ContiWiedemannSonnleitneretal.2018, author = {Conti, Fosca and Wiedemann, Leonhard and Sonnleitner, Matthias and Saidi, Abdessamad and Goldbrunner, Markus}, title = {Monitoring the mixing of an artificial model substrate in a scale-down laboratory digester}, volume = {2019}, journal = {Renewable Energy}, number = {132}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0960-1481}, doi = {https://doi.org/10.1016/j.renene.2018.08.013}, pages = {351 -- 362}, year = {2018}, language = {en} } @article{SaidiTrinklContietal.2018, author = {Saidi, Abdessamad and Trinkl, Christoph and Conti, Fosca and Goldbrunner, Markus and Karl, J{\"u}rgen}, title = {Partially Upgraded Biogas: Potential forDecentralized Utilization in AgriculturalMachinery}, volume = {41}, journal = {Chemical Engineering \& Technology}, number = {11}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-4125}, doi = {https://doi.org/10.1002/ceat.201800100}, pages = {2111 -- 2119}, year = {2018}, language = {en} } @article{MehtaEhrenwirthTrinkletal.2022, author = {Mehta, Kedar and Ehrenwirth, Mathias and Trinkl, Christoph and Z{\"o}rner, Wilfried}, title = {Towards Sustainable Community Development through Renewable Energies in Kyrgyzstan: A Detailed Assessment and Outlook}, volume = {3}, journal = {World}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2673-4060}, doi = {https://doi.org/10.3390/world3020018}, pages = {327 -- 343}, year = {2022}, abstract = {In rural Kyrgyzstan, the energy need is usually derived from multiple natural energy resources such as firewood, charcoal, agricultural residues, animal dung, and wood branches, which are considered common and predominant practices. Because of the non-sustainable resources and heavy reliance on the environment, Kyrgyzstan is one of the most vulnerable countries to climate change in Central Asia. On the contrary, the great renewable energy potential in Kyrgyzstan is untapped, which could be the most promising solution to ensuring sustainable energy supply in the country. However, because of the lack of scientific knowledge, current energy policies, and the lack of infrastructure, renewable resources are mainly untapped. To exploit the country's renewable energy potential, there is a need for a systematic diagnosis to develop a strategy to explore renewables in Kyrgyzstan, which is currently missing in the existing literature. In that regard, the presented study aims to assess the current status of renewable energy sources by considering the local energy context from a potential point of view. Further to this, it provides a comparative overview through a matrix of strengths, weaknesses, opportunities, and threats. Such novel analysis would be the fundamental base for formulating policy advice and a national plan to enhance the utilization of renewable energy in Kyrgyzstan. The presented analysis was carried out based on the extensive literature review, the country's national plan, and the existing energy policies of Kyrgyzstan. The article found out that there is huge potential available for the renewable energy market. As compared to other renewable energy sources, solar energy has great potential and can be considered one of the pioneer sustainable sources for integration into the country's power generation framework.}, language = {en} } @article{WernerMuschikEhrenwirthetal.2022, author = {Werner, Melanie and Muschik, Sebastian and Ehrenwirth, Mathias and Trinkl, Christoph and Schrag, Tobias}, title = {Sector Coupling Potential of a District Heating Network by Consideration of Residual Load and CO2 Emissions}, volume = {15}, pages = {6281}, journal = {Energies}, number = {17}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en15176281}, year = {2022}, abstract = {The growing share of fluctuating renewable electricity production within the German energy system causes the increasing necessity for flexible consumers, producers, and storage technologies to balance supply and demand. District heating networks with combined heat and power units, Power-to-Heat applications, and thermal energy storage capacities can serve as one of these flexible options. In this context, a simulation model of the district heating network of the rural community Dollnstein, Germany, was built. With the residual load of different regional areas (Germany, Bavaria, Eichst{\"a}tt, Dollnstein) it is investigated, how the heat generators can operate in an electricity market beneficial way. Two different control algorithms were evaluated: Due to a correlation between the residual loads and the CO2 emissions of the electricity mix, the CO2 savings achieved by this control algorithm are determined. Another way to operate electricity market beneficial is to consider the current CO2 emissions of each region. The main outcomes of this paper are, that there is a high potential for sector coupling by shifting the operation times of a CHP and a heat pump according to the residual load. The electricity demand of the heat pump can be met in terms of low CO2 emissions of the electricity mix, while the CHP can replace electricity with high CO2 emissions. These results can be improved, by considering not the residual load but the current CO2 emissions in the control algorithm.}, language = {en} } @article{ContiWiedemannSonnleitneretal.2017, author = {Conti, Fosca and Wiedemann, Leonhard and Sonnleitner, Matthias and Goldbrunner, Markus}, title = {Thermal behaviour of viscosity of aqueous cellulose solutions to emulate biomass in anaerobic digesters}, volume = {42}, journal = {New Journal of Chemistry}, number = {2}, publisher = {RSC}, address = {London}, issn = {1369-9261}, doi = {https://doi.org/10.1039/C7NJ03199H}, pages = {1099 -- 1104}, year = {2017}, language = {en} } @article{SaidiContiSonnleitneretal.2018, author = {Saidi, Abdessamad and Conti, Fosca and Sonnleitner, Matthias and Goldbrunner, Markus}, title = {Membrane separation process for small scaled partial biogas upgrading}, volume = {2018}, pages = {012012}, journal = {IOP Conference Series: Materials Science and Engineering}, number = {446}, publisher = {IOP Publishing}, address = {London}, issn = {1757-899X}, doi = {https://doi.org/10.1088/1757-899X/446/1/012012}, year = {2018}, abstract = {Biogas upgrading is actually limited to the production of biomethane as natural gas substitute. To realize the according gas quality a cost intensive methane enrichment is required, wherefore biogas upgrading is actually merely cost-efficient in case of high production rates. Since the energy and cost effort disproportionately increases with the required product gas purity partial biogas upgrading for decentralized utilization represents a promising utilization approach for farm based applications. Among the available technologies for CO2-separation the gas permeable membrane has high potential for small scaled biogas upgrading. Within the present study a model based analysis to determine the savings potential of a membrane based upgrading system is performed.}, language = {en} } @article{ContiWiedemannSaidietal.2018, author = {Conti, Fosca and Wiedemann, Leonhard and Saidi, Abdessamad and Goldbrunner, Markus}, title = {Effect of mixing of waste biomass in anaerobic digesters for production of biogas}, volume = {2018}, pages = {012011}, journal = {IOP Conference Series: Materials Science and Engineering}, number = {446}, publisher = {IOP Publishing}, address = {London}, issn = {1757-899X}, doi = {https://doi.org/10.1088/1757-899X/446/1/012011}, year = {2018}, abstract = {Biogas technology is an important renewable bioenergy producer. The biogas generating process needs to be optimized to minimise the energy consumption due to the stirring of biomass slurry. Numerical simulations and laboratory experiments are economically and practically preferred over investigations of industrial scale biogas plants. Additionally, a strategic approach to model the reality in scientific laboratories is to use a rheological valid artificial chemical substrate to replace real biomass. The proposes of this study were (i) to investigate the mixing process in a 1:12 scaled-down home-made laboratory digester filled with a 0.3 wt\% water-cellulose solution, (ii) to simulate the mixing process in the laboratory-scale digester using a computational fluid dynamics model, (iii) to validate the model by comparison of the simulation with laboratory experiments results obtained on the laboratory digester. Optical and acoustic measurements on the flow velocity inside the digester during the mixing process of the water-cellulose solutions indicate that the model based on computational fluid dynamics is valid. The data are presented and discussed in the paper.}, language = {en} } @article{MastHuemmerHolzhammeretal.2022, author = {Mast, Tanja and H{\"u}mmer, Benedikt and Holzhammer, Uwe and Grimm, Veronika and Hilpert, Johannes and Egerer, Jonas and Lang, Lukas Maximilian and Nysten, Jana and Pfefferer, Ulrike}, title = {Das Smart Market-Konzept als marktbasiertes Element im deutschen Engpassmanagement}, volume = {72}, journal = {et - Energiewirtschaftliche Tagesfragen}, number = {4}, publisher = {VDE Verlag}, address = {Berlin}, issn = {0013-743X}, pages = {53 -- 56}, year = {2022}, language = {de} } @article{FlachContiBayraktaretal.2022, author = {Flach, Charley and Conti, Fosca and Bayraktar, Ahmet and Goldbrunner, Markus}, title = {Direct Methanation and Storage Concepts for the Flexibilization of Biogas Plants}, volume = {46}, journal = {Chemical Engineering \& Technology}, number = {3}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-4125}, doi = {https://doi.org/10.1002/ceat.202200239}, pages = {579 -- 586}, year = {2022}, abstract = {Enrichment of the methane fraction in a biogas mixture is an innovative possibility to make existing biogas plants more flexible by using excess power. In the described concept, the CO2 in the biogas is directly catalytically converted into CH4 with H2. The CH4-enriched biogas is again fed into the digester to save energy for later use in the combined heat-and-power unit. Additionally, the fed heat gas can mix and heat the substrate. A heat pipe injector system was therefore developed for cooling the hot biogas stream after methanation and to prevent damage to the microbial consortia during the biomass mixing. The concept was proven at a laboratory-scale biogas plant.}, language = {en} } @article{BottEhrenwirthTrinkletal.2022, author = {Bott, Christoph and Ehrenwirth, Mathias and Trinkl, Christoph and Bayer, Peter}, title = {Component-based modeling of ground-coupled seasonal thermal energy storages}, volume = {2022}, pages = {118810}, journal = {Applied Thermal Engineering}, number = {214}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-5606}, doi = {https://doi.org/10.1016/j.applthermaleng.2022.118810}, year = {2022}, abstract = {Seasonal thermal energy storages are considered a central element of modern, innovative energy systems and help to harmonize fluctuating energy sources. Furthermore, they allow for an improved coupling between the electricity and heating sectors. Despite recent improvements of planning processes and enhanced models, significant discrepancies between projected and measured heat losses were revealed. Additional shortcomings of available tools relate to limitations in specifying geometry, internal design, or physical processes. Addressing these drawbacks, this study employs a revised, alternative approach by using a flexible, component-based, model ("STORE"). It allows variable flexible parameterizations to study diverse design scenarios. After introducing relevant seasonal thermal energy storage components, processes and mechanisms, datasets, and evaluation techniques, a plausibility test is presented that applies a common thermal energy storage model for benchmarking. In a test study, the re-use of a circa 1,000 m3 large swimming pool is simulated. STORE is used to investigate performance trends caused by different designs (e.g., insulation thicknesses, materials at individual interfaces). For the plausibility test, the results show a high degree of coverage and good applicability. Further, the results of the test study show a storage efficiency of 12.4\% for an uninsulated base case, which can be improved to 69.5\% in case of the most complex, highly insulated configuration. Critical trends are revealed, covering reduced peak capacity levels (26.5 to 23.5 MWh) and raised average filling temperatures (39.1 to 45.2 °C). Improved long-term behavior involves reduced environmental impacts due to reduced heating of the ambient soil (+7.9 K compared to +14.1 K after 2 years). General conclusions reveal that an optimal design should initially focus on an external cover of soil and top insulation. However, evaluations should base on multiple parameters depending on the target criteria. This is where the present model is highly useful. The capability of STORE to rapidly analyze a plethora of scenarios proves its high applicability for optimizing the planning processes of seasonal thermal energy storage projects.}, language = {en} } @article{ZoernerMahomedZuluetal.2020, author = {Z{\"o}rner, Wilfried and Mahomed, Nawaz and Zulu, Ackim and Bader, Tobias and Tenthani, Chifundo and Cuamba, Boaventura and Chingosho, Hilton}, title = {Meta-profile and competencies for harmonisation of higher education in sector-specific technology areas: A case study of Renewable Energy in Southern Africa}, volume = {8}, journal = {Tuning Journal for Higher Education}, number = {1}, publisher = {University of Deusto}, address = {Bilbao}, issn = {2386-3137}, doi = {https://doi.org/10.18543/tjhe-8(1)-2020pp75-97}, pages = {75 -- 97}, year = {2020}, language = {en} } @article{AhmedContiBayeretal.2022, author = {Ahmed, Arslan and Conti, Fosca and Bayer, Peter and Goldbrunner, Markus}, title = {Hydronic Road-Heating Systems}, volume = {26}, journal = {Environmental and Climate Technologies}, subtitle = {Environmental Performance and the Case of Ingolstadt Ramps}, number = {1}, publisher = {De Gruyter Poland}, address = {Warsaw}, issn = {2255-8837}, doi = {https://doi.org/10.2478/rtuect-2022-0078}, pages = {1044 -- 1054}, year = {2022}, abstract = {Snowfall and ice formation on road surface significantly impact the safety of driving conditions. To resolve this, every year salt and de-icing chemicals are sprinkled on roads. However, use of salts and snow ploughing have environmental as well as economical disadvantages. To resolve these problems, hydronic road heating systems are valid alternatives. Heat transfer fluid, i.e. mixture of ethanol and water, is pumped into a tubular circulation system under the asphalt. By this technology, the road and pavements shall stay ice-free even in times of snowfall and temperatures below the freezing point. The system can also be used to cool the asphalt in case of extreme heat, which - besides the heating effect - could also prevent road from damages in extreme summers. This study aims to compare the environmental impact of use of salts and road-heating system in terms of GHG emissions. To assess the environmental impact, an operational road heating system for a ramp in Ingolstadt, Germany, is considered. A cradle-to-grave analysis technique is used to determine the environmental effects based on a life-cycle assessment (LCA) framework. The analysis includes nine components solemnly responsible for hydronic heating of asphalt surface such as local heating pipe, insulation, pumps, and heat meters. Comparison is performed in terms of relative and total impact over 50-year lifetime of three heated ramps having 1989 m2 surface area in total. The results show that the asphalt and heating-circuit causes the major fraction (65 \%) of overall GHG emissions, with total life-time emissions of 28.10 kg CO2 eq./m2 of heated surface. During an operational life of 50 years, road heating systems emit 18 \% less CO2 eq./m2 as compared to the use of salts.}, language = {en} } @article{TissenBenzMenbergetal.2019, author = {Tissen, Carolin and Benz, Susanne and Menberg, Kathrin and Bayer, Peter and Blum, Philipp}, title = {Groundwater temperature anomalies in central Europe}, volume = {14}, pages = {104012}, journal = {Environmental Research Letters}, number = {10}, publisher = {IOP Publishing}, address = {Bristol}, issn = {1748-9326}, doi = {https://doi.org/10.1088/1748-9326/ab4240}, year = {2019}, abstract = {As groundwater is competitively used for drinking, irrigation, industrial and geothermal applications, the focus on elevated groundwater temperature (GWT) affecting the sustainable use of this resource increases. Hence, in this study GWT anomalies and their heat sources are identified. The anthropogenic heat intensity (AHI), defined as the difference between GWT at the well location and the median of surrounding rural background GWTs, is evaluated in over 10 000 wells in ten European countries. Wells within the upper three percentiles of the AHI are investigated for each of the three major land cover classes (natural, agricultural and artificial). Extreme GWTs ranging between 25 °C and 47 °C are attributed to natural hot springs. In contrast, AHIs from 3 to 10 K for both natural and agricultural surfaces are due to anthropogenic sources such as landfills, wastewater treatment plants or mining. Two-thirds of all anomalies beneath artificial surfaces have an AHI > 6 K and are related to underground car parks, heated basements and district heating systems. In some wells, the GWT exceeds current threshold values for open geothermal systems. Consequently, a holistic management of groundwater, addressing a multitude of different heat sources, is required to balance the conflict between groundwater quality for drinking and groundwater as an energy source or storage media for geothermal systems.}, language = {en} } @article{VannahmeBuschEhrenwirthetal.2023, author = {Vannahme, Anna and Busch, Jonas and Ehrenwirth, Mathias and Schrag, Tobias}, title = {Experimental Study of District Heating Substations in a Hardware-in-the-Loop Test Rig}, volume = {12}, pages = {43}, journal = {Resources}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2079-9276}, doi = {https://doi.org/10.3390/resources12040043}, year = {2023}, abstract = {This study compares two district heating substation systems for implementation in rural district heating networks with non-retrofitted single- and two-family houses. The aim is to determine which system has the potential to provide lower return temperatures and/or lower power peak demand. A hardware-in-the-loop-test rig was utilized to measure the two district heating substations under real operation conditions. This experimental study demonstrates that load balancing of the district heating network is attainable with the district heating substation with storage. This is especially advantageous when there is a high demand for domestic hot water. Overall, both systems yield comparable return temperatures.}, language = {en} } @article{IgiligiVielhauerEhrenwirthetal.2023, author = {Igiligi, Anthony and Vielhauer, Armin and Ehrenwirth, Mathias and Hurm, Christian and Summ, Thorsten and Trinkl, Christoph and Navarro Gevers, Daniel}, title = {Assessment of Conservation Voltage Reduction in Distribution Networks with Voltage Regulating Distribution Transformers}, volume = {16}, pages = {3155}, journal = {Energies}, number = {7}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en16073155}, year = {2023}, abstract = {The application of voltage reduction in medium and low voltage grids to reduce peak power demand or energy consumption has been implemented since the 1980s using several approaches. Conservation Voltage Reduction (CVR), as one such approach, uses a voltage control device to reduce or increase the voltage setpoint on a busbar, thereby reducing or increasing the amount of active and reactive power supply in the network. Voltage regulation for CVR is always implemented according to established network planning standards in each country. Research in this field has proven that a CVR factor (CVRf) of 0.7-1.5 for peak demand reduction can be achieved. This is an evaluation metric of CVR. The aim of this research is to determine and validate CVRf for peak demand reduction by comparing actual results obtained during regular tap changes with other randomly distributed periods outside tap change operations, using a set of measurement data. It is important to understand CVR deployment capability by evaluating CVR potentials from historical random tap operations before a robust network-wide deployment is introduced. This research provides such guidance. It also provides a novel approach to determining tap changes from voltage measurements using a time-based algorithm. A CVRf ranging from 0.95 to 1.61 was estimated using a measurement dataset from a test field. The result of the entire evaluation shows that the CVRf are smaller during peak PV production and greater during peak demand periods. Further evaluation using statistical hypotheses testing and a control chart was used to validate the evaluation.}, language = {en} } @article{HemmerleHaleDresseletal.2019, author = {Hemmerle, Hannes and Hale, Sina and Dressel, Ingo and Benz, Susanne and Attard, Guillaume and Blum, Philipp and Bayer, Peter}, title = {Estimation of Groundwater Temperatures in Paris, France}, volume = {2019}, pages = {5246307}, journal = {Geofluids}, publisher = {Hindawi}, address = {London}, issn = {1468-8123}, doi = {https://doi.org/10.1155/2019/5246307}, year = {2019}, abstract = {Subsurface temperature data is usually only accessible as point information with a very limited number of observations. To spatialize these isolated insights underground, we usually rely on interpolation methods. Unfortunately, these conventional tools are in many cases not suitable to be applied to areas with high local variability, like densely populated areas, and in addition are very vulnerable to uneven distributions of wells. Since thermal conditions of the surface and shallow subsurface are coupled, we can utilize this relationship to estimate shallow groundwater temperatures from satellite-derived land surface temperatures. Here, we propose an estimation approach that provides spatial groundwater temperature data and can be applied to natural, urban, and mixed environments. To achieve this, we combine land surface temperatures with anthropogenic and natural processes, such as downward heat transfer from buildings, insulation through snow coverage, and latent heat flux in the form of evapotranspiration. This is demonstrated for the city of Paris, where measurements from as early as 1977 reveal the existence of a substantial subsurface urban heat island (SUHI) with a maximum groundwater temperature anomaly of around 7 K. It is demonstrated that groundwater temperatures in Paris can be well predicted with a root mean squared error of below 1 K by means of satellite-derived land surface images. This combined approach is shown to improve existing estimation procedures that are focused either on rural or on urban conditions. While they do not detect local hotspots caused by small-scaled heat sources located underground (e.g., sewage systems and tunnels), the findings for the city of Paris for the estimation of large-scale thermal anomalies in the subsurface are promising. Thus, the new estimation procedure may also be suitable for other cities to obtain a more reliable insight into the spatial distribution of urban ground and groundwater temperatures.}, language = {en} } @article{TissenMenbergBayeretal.2019, author = {Tissen, Carolin and Menberg, Kathrin and Bayer, Peter and Blum, Philipp}, title = {Meeting the demand}, volume = {7}, pages = {9}, journal = {Geothermal Energy - Science, Society and Technology}, subtitle = {geothermal heat supply rates for an urban quarter in Germany}, publisher = {BioMed Central}, address = {London}, issn = {2195-9706}, doi = {https://doi.org/10.1186/s40517-019-0125-8}, year = {2019}, abstract = {Thermal energy for space heating and for domestic hot water use represents about a third of the overall energy demand in Germany. An alternative to non-renewable energy-based heat supply is the implementation of closed and open shallow geothermal systems, such as horizontal ground source heat pump systems, vertical ground source heat pump (vGSHP) systems and groundwater heat pump systems. Based on existing regulations and local hydrogeological conditions, the optimal site-specific system for heat supply has to be identified. In the presented technical feasibility study, various analytical solutions are tested for an urban quarter before and after building refurbishment. Geothermal heat supply rates are evaluated by providing information on the optimal system and the specific shortcomings. Our results show that standard vGSHP systems are even applicable in older and non-refurbished residential areas with a high heat demand using a borehole heat exchanger with a length of 100 m or in conjunction with multiple boreholes. After refurbishment, all studied shallow geothermal systems are able to cover the lowered heat demand. The presented analysis also demonstrates that ideally, various technological variants of geothermal systems should be evaluated for finding the optimal solution for existing, refurbished and newly developed residential areas.}, language = {en} } @article{RingelSomogyvariJalalietal.2019, author = {Ringel, Lisa Maria and Somogyv{\´a}ri, M{\´a}rk and Jalali, Mohammadreza and Bayer, Peter}, title = {Comparison of Hydraulic and Tracer Tomography for Discrete Fracture Network Inversion}, volume = {9}, pages = {274}, journal = {Geosciences}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {2076-3263}, doi = {https://doi.org/10.3390/geosciences9060274}, year = {2019}, abstract = {Fractures serve as highly conductive preferential flow paths for fluids in rocks, which are difficult to exactly reconstruct in numerical models. Especially, in low-conductive rocks, fractures are often the only pathways for advection of solutes and heat. The presented study compares the results from hydraulic and tracer tomography applied to invert a theoretical discrete fracture network (DFN) that is based on data from synthetic cross-well testing. For hydraulic tomography, pressure pulses in various injection intervals are induced and the pressure responses in the monitoring intervals of a nearby observation well are recorded. For tracer tomography, a conservative tracer is injected in different well levels and the depth-dependent breakthrough of the tracer is monitored. A recently introduced transdimensional Bayesian inversion procedure is applied for both tomographical methods, which adjusts the fracture positions, orientations, and numbers based on given geometrical fracture statistics. The used Metropolis-Hastings-Green algorithm is refined by the simultaneous estimation of the measurement error's variance, that is, the measurement noise. Based on the presented application to invert the two-dimensional cross-section between source and the receiver well, the hydraulic tomography reveals itself to be more suitable for reconstructing the original DFN. This is based on a probabilistic representation of the inverted results by means of fracture probabilities.}, language = {en} } @article{SchweizerTutunaruHolzhammer2022, author = {Schweizer, Manuel and Tutunaru, Robin and Holzhammer, Uwe}, title = {Energie- und Leistungsbedarf des elektrischen Individualverkehrs}, volume = {74}, journal = {BWK ENERGIE.}, number = {7-8}, publisher = {VDI fachmedien}, address = {D{\"u}sseldorf}, issn = {1618-193X}, doi = {doi.org/10.37544/1618-193X-2022-7-8}, pages = {44 -- 48}, year = {2022}, language = {de} } @article{SchweizerStoecklTutunaruetal.2023, author = {Schweizer, Manuel and St{\"o}ckl, Martin and Tutunaru, Robin and Holzhammer, Uwe}, title = {Influence of heating, air conditioning and vehicle automation on the energy and power demand of electromobility}, volume = {2023}, pages = {100443}, journal = {Energy Conversion and Management: X}, number = {20}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2590-1745}, doi = {https://doi.org/10.1016/j.ecmx.2023.100443}, year = {2023}, abstract = {With the increasing number of electric vehicles in the transport sector, the relevance of accurate energy and power demand predictions of electromobility is growing. Thereby, different vehicle functions, especially heating and air conditioning and vehicle automation, have a significant influence. In accordance with the upcoming Euro-7 emissions standard, the energy consumption for heating even has to be contained in the manufacturer's consumption data in the future. To increase the accuracy of energy and power demand predictions of electromobility, the energy consumption of vehicle functions such as heating and air conditioning as well as the energy savings through vehicle automation must be considered. This paper presents approaches for modeling and simulation the energy consumption of heating, air conditioning and vehicle automation which can be used as an extension of electric vehicles WLTP (Worldwide Harmonized Light-Duty Vehicles Test Procedure) consumption simulation on the level of vehicle classes. The Germany-wide results of the electric vehicles energy demand for heating and air conditioning on the level of NUTS3-areas (Nomenclature of territorial units for statistics) and vehicle classes show regionally different results and confirm the relevance of the research approach. Vehicle automation results are described on the level of the five SAE automation levels (Society of Automotive Engineers automation levels) and the vehicle classes. The approaches and results can be used for single vehicles or assumed vehicle fleets.}, language = {en} } @article{SummEhrenwirthTrinkletal.2023, author = {Summ, Thorsten and Ehrenwirth, Mathias and Trinkl, Christoph and Z{\"o}rner, Wilfried and Pischow, Kaj and Greenough, Richard and Oyinlola, Muyiwa}, title = {Effect of argon concentration on thermal efficiency of gas-filled insulating glass flat-plate collectors}, volume = {2023}, pages = {120657}, journal = {Applied Thermal Engineering}, number = {230, Part A}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-5606}, doi = {https://doi.org/10.1016/j.applthermaleng.2023.120657}, year = {2023}, abstract = {Insulating glass flat-plate collectors can save cost by being produced quickly and automatically in insulated glass production facilities, and they can be filled with argon to reduce heat loss. During its lifetime, the collector is likely to lose argon because of gradual material degradation of the sealing. However, information on the influence of the argon concentration on the collector efficiency is limited. Therefore, the objective of this research work was to analyse this effect. A theoretical material property calculation of argon-air mixtures was carried out to determine the convective losses with variable argon concentrations. Thermal collector performance was measured experimentally using an outdoor solar tracker test rig. The results strongly suggest, that the influence of argon concentration on both the convective losses and the thermal efficiency is non-linear. The measurements revealed that an argon concentration of 90 \% can increase average thermal performance by 6.7 ± 4.8 percentage points. An increase in argon concentration from 0 \% to 50 \% has almost twice the effect on average thermal efficiency as an increase from 50 \% to 90 \%. Concluding from these results, an argon leakage threshold of 2.5 percentage points per year is proposed to avoid disproportionate loss of efficiency over time.}, language = {en} } @article{BesnerMehtaZoerner2023, author = {Besner, Rebekka and Mehta, Kedar and Z{\"o}rner, Wilfried}, title = {How to Enhance Energy Services in Informal Settlements?}, volume = {16}, pages = {4687}, journal = {Energies}, subtitle = {Qualitative Comparison of Renewable Energy Solutions}, number = {12}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en16124687}, year = {2023}, abstract = {More than half of the urban population of Sub-Saharan Africa lives in informal housing conditions. While urban areas are, in general, characterized by a high electrification rate, residents of informal settlements are still affected by energy poverty, the use of traditional energy sources and unreliable electricity supply. The aim of the study is to give an overview of different renewable-energybased solutions which are able to improve local energy provision. These are Solar Home Systems, Mini-Grids, and Energy-Hubs. The technologies are compared to another option for improving energy supply, namely Grid Expansion. The analysis is based on 24 Key Performance Indicators, which can be classified into technical, economic, environmental, social, and political dimensions. The selection of indicators is based on the challenges prevalent in informal settlements that impede a comprehensive, sustainable energy supply. The literature-based indices are used to determine which of the four technologies is a suitable solution for minimizing the challenges prevailing in informal settlements. The resulting matrix provides a holistic comparison and serves as a decision aid in selecting the appropriate technology for future projects in informal settlements, depending on local conditions and the needs of the population. The results show that the Energy-Hub is a valid alternative for energy supply improvement in Informal Settlements.}, language = {en} } @article{PophillatAttardBayeretal.2018, author = {Pophillat, William and Attard, Guillaume and Bayer, Peter and Hecht-M{\´e}ndez, Jozsef and Blum, Philipp}, title = {Analytical solutions for predicting thermal plumes of groundwater heat pump systems}, volume = {2020}, journal = {Renewable Energy}, number = {147, Part 2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-0682}, doi = {https://doi.org/10.1016/j.renene.2018.07.148}, pages = {2696 -- 2707}, year = {2018}, language = {en} } @article{AttardBayerRossieretal.2019, author = {Attard, Guillaume and Bayer, Peter and Rossier, Yvan and Blum, Philipp and Eisenlohr, Laurent}, title = {A novel concept for managing thermal interference between geothermal systems in cities}, volume = {2020}, journal = {Renewable Energy}, number = {145}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-0682}, doi = {https://doi.org/10.1016/j.renene.2019.06.095}, pages = {914 -- 924}, year = {2019}, language = {en} }