TY - JOUR A1 - Rupp, Matthias A1 - Rieke, Christian A1 - Handschuh, Nils A1 - Kuperjans, Isabel T1 - Economic and ecological optimization of electric bus charging considering variable electricity prices and CO₂eq intensities JF - Transportation Research Part D: Transport and Environment N2 - In many cities, diesel buses are being replaced by electric buses with the aim of reducing local emissions and thus improving air quality. The protection of the environment and the health of the population is the highest priority of our society. For the transport companies that operate these buses, not only ecological issues but also economic issues are of great importance. Due to the high purchase costs of electric buses compared to conventional buses, operators are forced to use electric vehicles in a targeted manner in order to ensure amortization over the service life of the vehicles. A compromise between ecology and economy must be found in order to both protect the environment and ensure economical operation of the buses. In this study, we present a new methodology for optimizing the vehicles’ charging time as a function of the parameters CO₂eq emissions and electricity costs. Based on recorded driving profiles in daily bus operation, the energy demands of conventional and electric buses are calculated for the passenger transportation in the city of Aachen in 2017. Different charging scenarios are defined to analyze the influence of the temporal variability of CO₂eq intensity and electricity price on the environmental impact and economy of the bus. For every individual day of a year, charging periods with the lowest and highest costs and emissions are identified and recommendations for daily bus operation are made. To enable both the ecological and economical operation of the bus, the parameters of electricity price and CO₂ are weighted differently, and several charging periods are proposed, taking into account the priorities previously set. A sensitivity analysis is carried out to evaluate the influence of selected parameters and to derive recommendations for improving the ecological and economic balance of the battery-powered electric vehicle. In all scenarios, the optimization of the charging period results in energy cost savings of a maximum of 13.6% compared to charging at a fixed electricity price. The savings potential of CO₂eq emissions is similar, at 14.9%. From an economic point of view, charging between 2 a.m. and 4 a.m. results in the lowest energy costs on average. The CO₂eq intensity is also low in this period, but midday charging leads to the largest savings in CO₂eq emissions. From a life cycle perspective, the electric bus is not economically competitive with the conventional bus. However, from an ecological point of view, the electric bus saves on average 37.5% CO₂eq emissions over its service life compared to the diesel bus. The reduction potential is maximized if the electric vehicle exclusively consumes electricity from solar and wind power. Y1 - 2020 U6 - https://doi.org/10.1016/j.trd.2020.102293 SN - 1361-9209 VL - 81 IS - Article 102293 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Paulsen, Svea A1 - Hoffstadt, Kevin A1 - Krafft, Simone A1 - Leite, A. A1 - Zang, J. A1 - Fonseca-Zang, W. A1 - Kuperjans, Isabel T1 - Continuous biogas production from sugarcane as sole substrate T2 - Energy Reports N2 - A German–Brazilian research project investigates sugarcane as an energy plant in anaerobic digestion for biogas production. The aim of the project is a continuous, efficient, and stable biogas process with sugarcane as the substrate. Tests are carried out in a fermenter with a volume of 10 l. In order to optimize the space–time load to achieve a stable process, a continuous process in laboratory scale has been devised. The daily feed in quantity and the harvest time of the substrate sugarcane has been varied. Analyses of the digester content were conducted twice per week to monitor the process: The ratio of inorganic carbon content to volatile organic acid content (VFA/TAC), the concentration of short-chain fatty acids, the organic dry matter, the pH value, and the total nitrogen, phosphate, and ammonium concentrations were monitored. In addition, the gas quality (the percentages of CO₂, CH₄, and H₂) and the quantity of the produced gas were analyzed. The investigations have exhibited feasible and economical production of biogas in a continuous process with energy cane as substrate. With a daily feeding rate of 1.68gᵥₛ/l*d the average specific gas formation rate was 0.5 m3/kgᵥₛ. The long-term study demonstrates a surprisingly fast metabolism of short-chain fatty acids. This indicates a stable and less susceptible process compared to other substrates. Y1 - 2020 U6 - https://doi.org/10.1016/j.egyr.2019.08.035 N1 - 6th International Conference on Energy and Environment Research, ICEER 2019, 22–25 July, University of Aveiro, Portugal VL - 6 IS - Supplement 1 SP - 153 EP - 158 PB - Elsevier ER - TY - JOUR A1 - Kuperjans, Isabel T1 - Exergetische und exergoökonomische Analyse thermischer Prozesse JF - Arbeitsbericht / Institut für Wirtschaftswissenschaften, Rheinisch-Westfälische Technische Hochschule Aachen Y1 - 1996 IS - 06 ER - TY - CHAP A1 - Kaspar, K. A1 - Groebel, Simone A1 - Kuperjans, Isabel A1 - Dielmann, Klaus-Peter A1 - Selmer, Thorsten T1 - Charakterisierung der Biozönose von Biogasfermentern in Abhängigkeit verschiedener Substrate T2 - Biogas 2013 : 6. Innovationskongress, 23. - 24.05.2013, Osnabrück, Tagungsband Y1 - 2013 SN - 978-3-9813776-3-7 SP - 69 EP - 74 PB - Profair Consult+Project CY - Hildesheim ER - TY - CHAP A1 - Augenstein, Eckardt A1 - Herbergs, S. A1 - Kuperjans, Isabel A1 - Lucas, K. ED - Kjelstrup, Signe T1 - Simulation of industrial energy supply systems with integrated cost optimization T2 - Proceedings of ECOS 2005, the 18th International Conference on Efficiency, Cost, Optimization, Simulation, and Environmental Impact of Energy Systems : Trondheim, Norway, June 20 - 22, 2005. - Vol. 2 Y1 - 2005 SN - 82-519-2041-8 N1 - CD-ROM-Ausg. u.d.T.: Shaping our future energy systems SP - 627 EP - 634 PB - Tapir Academic Press CY - Trondheim ER - TY - CHAP A1 - Küppers, Christine A1 - Groebel, Simone A1 - Kuperjans, Isabel A1 - Dielmann, Klaus-Peter T1 - Molekulargenetische Analysen zur Optimierung der Biogasgewinnung T2 - Biogas 2011 : 4. Innovationskongress ; Effizienzsteigerung von Biogasanlagen ; Vorstellung der 17 besten Biogas-Innovationen der letzten 12 Monate ; 12. - 13. Mai 2011, im ZUK der Deutschen Bundesstiftung Umwelt ; Tagungsband Y1 - 2011 SN - 978-3-9813776-1-3 SP - 45 EP - 48 PB - Profair Consult+Project CY - Hildesheim ER - TY - CHAP A1 - Augenstein, Eckardt A1 - Herbergs, S. A1 - Kuperjans, Isabel T1 - Planung und Bewertung der Gebäudeenergieversorgung mit TOP-Energy T2 - Heizungs- und Raumlufttechnik : 1. Fachtagung Leonberg, 31. Januar bis 1. Februar 2006. - (VDI-Berichte ; Nr. 1921) Y1 - 2006 SN - 3-18-091921-3 N1 - Posterbeitrag SP - 57 EP - 60 PB - VDI-Verl. CY - Düsseldorf ER - TY - CHAP A1 - Kuperjans, Isabel A1 - Schreiber, M. A1 - Determann, L. A1 - Schreiber, R. T1 - Entscheidungsunterstützung bei der Gestaltung der betrieblichen Energieversorgung und -nutzung T2 - Innovationen bei der rationellen Energieanwendung : neue Chancen für die Wirtschaft ; Tagung Dortmund, 3. und 4. März 1998. - (VDI-Berichte ; 1385) Y1 - 1998 SN - 3-18-091385-1 SP - 79 EP - 94 PB - VDI-Verl. CY - Düsseldorf ER - TY - CHAP A1 - Augenstein, Eckardt A1 - Gürzenich, D. A1 - Kuperjans, Isabel A1 - Wrobel, G. T1 - TOP-Energy : softwaregestützte Analyse und Optimierung industrieller Energieversorgungssysteme T2 - Entwicklungslinien der Energietechnik 2004 Y1 - 2004 N1 - Themengebiet Energiesysteme PB - VDI CY - Düsseldorf ET - CD-ROM-Ausg. ER - TY - CHAP A1 - Augenstein, Eckardt A1 - Kuperjans, Isabel A1 - Lucas, K. ED - Tsatsaronis,, Georgios T1 - EUSEBIA - Decision-Support-System for Technical, Economical and Ecological Design and Evaluation of Industrial Energy Systems T2 - ECOS 2002 : proceedings of the 15th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems, Berlin, Germany July 3 - 5, 2002. - Vol. 1 Y1 - 2002 SN - 3-00-009533-0 SP - 446 EP - 453 PB - Techn. Univ., Inst. for Energy Engineering CY - Berlin ER -