04 Fakultät Energie-, Verfahrens- und Biotechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/5
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Item Open Access Findings from measurements of the electric power demand of air compressors(2021) Hummel, Ulf; Radgen, Peter; Ülker, Sercan; Schelle, RalphThe compressed air electric ratio (CAER) describes the ratio of the real electric power demand to the nominal mechanical power of an air compressor. The CAER is an important indicator as the electric power demand of air compressors varies throughout its operation dependent on compressor technology, pressure ratio, and free air delivery. The nameplate power of the compressor drive motor is not sufficient for evaluating the electric power demand; therefore, the CAER plays an important role in assessing the electric operating power demand. In this paper, results from measurements of fixed speed and variable speed (VFD) compressors are presented with the analysis of key influencing factors of the CAER. The data show that the pressure ratio of operating pressure to the maximum design outlet pressure has the largest impact on the CAER. For VFD compressors, the CAER is represented as a linear function dependent on the respective load. Fixed and variable speed compressors’ CAERs are always dependent on the load condition. In idle condition, the CAER was measured to be 0.2. In full load condition with a pressure ratio of 0.6, the CAER averages at a value of 0.87, meaning a 90 kW compressor at 0.6 pressure ratio draws 78.3 kW electric power.Item Open Access Development of scenarios for a multi-model system analysis based on the example of a cellular energy system(2020) Kühnbach, Matthias; Guthoff, Felix; Bekk, Anke; Eltrop, LudgerScenario analysis combined with system and market modelling is a well-established method to evaluate technological and societal developments and their impacts on future energy pathways. This paper presents a process-oriented method for developing consistent energy scenarios using multiple energy system models. Its added value is that the developed energy scenarios are consistent in a multi-model environment and practicable for a broader target group from scientists to practitioners. The scenarios consist of comprehensive storylines and systematically defined quantitative parameters. Following a step-by-step process, a condensed set of overlapping descriptors is generated and used to define the scenarios in a consistent parameter matrix. The set of descriptors allow consistent and comparable outputs independent of model-specific characteristics. The corresponding quantitative parameters can be used by diverse energy system tools. Using multiple models, a team of researchers can explore questions from differing points of view. In an example study, we apply the method to develop scenarios in the context of a cellular energy system. This approach enables the development of scenarios that provide a consistent basis for both stakeholder discourse and multi-model system analysis.Item Open Access Optimized data center site selection : mesoclimatic effects on data center energy consumption and costs(2021) Turek, Dirk; Radgen, PeterThe effect of the location on the energy consumption of data centers has already been studied in detail on the macro-climatic level. To take advantage of these effects, however, it is usually necessary for the location of data centers to cross international borders. The influence of site changes within national borders and in a small radius of < 100 km has not yet been quantified. To investigate this, a dynamic mathematical model of the temperature-dependent components of a reference data center was created and the influence on the energy consumption in an area of 240 × 215 km in Germany was investigated. It could be shown that even small changes of the location within a 10 km radius of a location lead to annual energy savings in the recirculating chiller of 9.12% on average (maximum 56.58%). With a freedom of location of 100 km within national borders, savings of 37.35% on average (maximum 76.11%) are even possible. Location-dependent optimizations are therefore also relevant at local and national level with regard to their influence on energy consumption, and the consideration of mesoclimatic aspects should be an elementary part of the site selection process for data centers in the future.Item Open Access Implementing household heterogeneity in a multi-regional technology based energy-economic model : system analysis on distributional impacts of pan-European energy and environmental policies(Stuttgart : Universität Stuttgart, Institut für Energiewirtschaft und Rationelle Energieanwendung, 2024) Cunha Montenegro, Roland; Hufendiek, Kai (Prof. Dr.-Ing.)The European Union (EU) set ambitious targets for the reduction of greenhouse gases until 2030 in order to achieve the 1.5C objective of the Paris Agreement. Among the measures to reach this goal, carbon pricing is a promising one as it increases the costs of polluting activities and makes the use of clean technologies more attractive. While this mechanism is already used in energy-intensive sectors, such as energy conversion and chemicals, its application on the remaining sectors of the economy is treated with caution, since economical and social outputs are unclear and might jeopardize the long-term will to cut emissions. This work aims to add on understanding the socio-economic effects of a multi-regional carbon pricing scheme with focus on the household sector. It proposes that each EU Member State implements a national cap-and-trade system, where the carbon price is defined according to supply and demand of CO2 certificates. Furthermore, four revenue redistribution mechanisms are explored: reduced consumption taxes, reduced labor taxes, equal per capita redistribution and per capita redistribution according to income levels. For the analysis, a global Computable General Equilibrium model is expanded to represent distinct income groups. This feature allows for the model to assess not only economic effects, as GDP development, but also social implications, such as income distribution and tax burden across different households. Finally, it is possible to assess whether the analyzed policies lead to a double dividend, in which emissions are reduced and GDP increases, and even a social dividend, characterized by decreased income inequality. The results indicate that no revenue redistribution scheme lead to significant improvement in GDP, but each one helps decreasing certain negative aspects of pricing carbon. Reducing consumption and labor taxes lead to the highest employment levels among the analyzed policies, while per capita redistribution helps decreasing income inequality. Additionally, consumption of electricity and fossil-fuels varies according to redistribution mechanism, which is an important input for multi-model analysis.Item Open Access Analysis and prediction of electromobility and energy supply by the example of Stuttgart(2021) Wörner, Ralf; Morozova, Inna; Cao, Danting; Schneider, Daniela; Neuburger, Martin; Mayer, Daniel; Körner, Christian; Kagerbauer, Martin; Kostorz, Nadine; Blesl, Markus; Jochem, Patrick; Märtz, AlexandraThis paper seeks to identify bottlenecks in the energy grid supply regarding different market penetration of battery electric vehicles in Stuttgart, Germany. First, medium-term forecasts of electric and hybrid vehicles and the corresponding charging infrastructure are issued from 2017 to 2030, resulting in a share of 27% electric vehicles by 2030 in the Stuttgart region. Next, interactions between electric vehicles and the local energy system in Stuttgart were examined, comparing different development scenarios in the mobility sector. Further, a travel demand model was used to generate charging profiles of electric vehicles under consideration of mobility patterns. The charging demand was combined with standard household load profiles and a load flow analysis of the peak hour was carried out for a quarter comprising 349 households. The simulation shows that a higher charging capacity can lead to a lower transformer utilization, as charging and household peak load may fall temporally apart. Finally, it was examined whether the existing infrastructure is suitable to meet future demand focusing on the transformer reserve capacity. Overall, the need for action is limited; only 10% of the approximately 560 sub-grids were identified as potential weak points.Item Open Access On the way to a sustainable European energy system : setting up an integrated assessment toolbox with TIMES PanEU as the key component(2020) Korkmaz, Pinar; Cunha Montenegro, Roland; Schmid, Dorothea; Blesl, Markus; Fahl, UlrichThe required decarbonization of the energy system is a complex task, with ambitious targets under the Paris Agreement, and related policy analysis should consider possible impacts on the economy and society. By coupling the energy system model TIMES PanEU with the impact assessment model EcoSense and the computable general equilibrium model NEWAGE, we present an integrated assessment toolbox for the European energy system capable of internalizing health damage costs of air pollution while simultaneously accounting for demand changes in energy services caused by economic feedback loops. The effects of each coupling step are investigated in a scenario analysis. Additionally, CO2 decomposition analysis is applied to identify the main drivers to decarbonize the energy system. Our results show that integrating externalities forces the system to take early action, which provides benefits on the societal level. Including macro-economic variables has a negative effect on energy service demands and generally reduces the need for structural change, which are still the main drivers of decarbonization. The tighter the models are coupled, the fewer the iterations needed and the lower the CO2 prices resulting from the carbon cap and trade system. In this aspect, an integrated view can provide valuable insights to determine efficient and effective decarbonization paths.Item Open Access Long-term distributional impacts of European cap-and-trade climate policies : a CGE multi-regional analysis(2019) Cunha Montenegro, Roland; Lekavičius, Vidas; Brajković, Jurica; Fahl, Ulrich; Hufendiek, KaiCarbon pricing is a policy with the potential to reduce CO2 emissions in the household sector and support the European Union in achieving its environmental targets by 2050. However, the policy faces acceptance problems from the majority of the public. In the framework of the project Role of technologies in an energy efficient economy-model-based analysis of policy measures and transformation pathways to a sustainable energy system (REEEM), financed by the European Commission under the Horizon 2020 program, we investigate the effects of such a policy in order to understand its challenges and opportunities. To that end, we use a recursive-dynamic multi-regional Computable General Equilibrium model to represent carbon pricing as a cap-and-trade system and calculate its impacts on consumption of energy goods, incidence of carbon prices, and gross income growth for different income groups. We compare one reference scenario and four scenario variations with distinct CO2 reduction targets inside and outside of the EU. The results demonstrate that higher emission reductions, compared to the reference scenario, lead to slower Gross Domestic Product growth, but also produce a more equitable increase of gross income and can help reduce income inequalities. In this case, considering that the revenues of carbon pricing are paid back to the households, the gross income of the poorest quintile grows as much as, or even more in some cases, than the gross income of the richest quintile.