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[en] The author investigated the substitution of conventional fuels by biofuels in terms of airborne emission ratings. The method is similar to that of product ecobalancing, i.e. the full life cycle of energy sources is considered and several categories of effects are taken into account: Consumption of fossil resources, greenhouse effect, acidification, depletion of stratospheric ozone, human toxicity and ecotoxicity
[de]Die vorliegende Arbeit untersucht fuer verschiedene luftgetragene Emissionen die Veraenderungen, die sich in Deutschland bei der Substitution konventioneller Kraftstoffe durch Biokraftstoffe ergeben. Die Vorgehensweise lehnt sich an die Methodik zur Erstellung von Produkt-Oekobilanzen an; so werden beispielsweise die vollstaendigen Lebenswege der Energietraeger betrachtet. Zur Beurteilung werden verschiedene Wirkungskategorien herangezogen: der Verbrauch fossiler Energieressourcen, der Treibhauseffekt, die Versauerung, der Ozonabbau in der Stratosphaere sowie Human- und Oekotoxizitaet. (orig.)
[en] Against the background of an increasing importance of climate change mitigation and the liberalization of the European energy supply this study assesses the perspectives of power plants with Carbon dioxide Capture and Storage (CCS). CCS power plants represent one option to reduce CO_2 emissions of fossil energy based electricity production significantly. In this study the deployment of CCS power plants is investigated for the European electricity market until 2050 taking different energy and climate policy framework conditions into consideration. By applying an integrated model-based approach, structural changes of the whole energy system are incorporated, including their implications on costs and emissions. The study addresses uncertainties concerning future CCS power plant invest costs and efficiencies explicitly, and analyses the effects of changes of these parameters with respect to the perspectives of CCS power plants in Europe. Thereby, interdependencies on horizontal level related to competition of different technologies within the electricity sector are examined, but also vertical interdependencies resulting from effects between the upstream and energy demand sectors. In order to reflect the heterogeneity among the national energy systems in Europe, country specific particularities on technical aspects and energy policy are taken into account, such as potentials and costs of CO_2 storage, and national regulations on the use of nuclear power and renewable energy. The results of the analysis reveal a strong influence of the stringency of the EU greenhouse gas reduction target and the policy on the use of nuclear energy on the perspectives of CCS power plants in the European electricity market. Comparing the influence of different policy frameworks analysed in this study with the influences of the variation of the technical and economic CCS power plant parameters shows, that uncertainties concerning energy policy measures can have a stronger influence on the perspectives of CCS in Europe than uncertainties regarding invest costs and efficiencies. For certain market conditions this also means, that reduced market perspectives of CCS technologies, which might happen due to changes of the energy policy framework, cannot entirely be offset by increasing the efficiencies and reducing the invest costs of CCS power plants. Changes of CCS power plant parameters impact both an increase of the electricity demand and the substitution of alternative generation technologies. In the mid-term, mainly fossil-based electricity generation without CCS is substituted as result of reductions of invest costs and increases of efficiencies of CCS power plants, and in the long-run mainly the electricity generation from renewable energy.
[en] The transport sector is facing the challenges of satisfying the ever increasing transport demand on the one hand and achieving greenhouse gas (GHG) emission reduction targets without compromising economic development on the other hand. There are various alternative fuels and powertrains which might play a role in the future of the German transport sector. Amongst these options, biofuels are considered to help lower GHG emissions. However, they are severely criticized to create an additional strain for the energy system and particularly for the transport sector with land area requirement for energy crop production, which may imply a competition with food production. This study aims to assess the future role of alternative fuels and powertrains in the German transport sector in terms of their costs, efficiencies, GHG emissions and land area requirement for energy crops. To fulfill this aim, a techno-economic analysis of all relevant fuels and powertrain options was performed and a model based approach was employed. The utilized model belongs to the TIMES (The Integrated MARKAL EFOM System) family and is a bottom-up linear cost optimization energy system model. A scenario analysis was employed in order to assess the effect of different technological, economic, environmental and political conditions on the overall system. The results of the scenario analysis indicated that the transport system will still be dominated by conventional powertrains in 2030. Alternative powertrains are projected to play only a secondary role until 2030. It is not expected that fuel cell or battery electric passenger cars will be introduced into the market until 2030 in Germany. Nevertheless, hybrid electric powertrains have to be used in the German passenger car sector under ambitious GHG emission reduction targets and high oil prices. The introduction of alternative powertrains (such as hybrid electric and fuel cell powertrain) is much more likely in the bus sector (especially for public buses) than in passenger cars or in the road freight sector. Furthermore conventional fuels are expected to remain an important part of the German transport system until 2030. However, not only conventional fuels will be utilized in the future, but also biofuels and hydrogen are required. It is concluded that the transport sector should not be the first sector to reduce GHG emissions within an overall GHG emission mitigation strategy. However, with the ambitious GHG emission reduction targets (such as self-commitment of the German government) some contributions should also come from the transport sector.
[en] Energy efficiency is a highly important topic and currently omnipresent in the energy political discussion. Despite this high importance there's no common understanding even concerning the definition of the term energy efficiency. In addition, there are plenty so called energy efficiency targets and several indicators. Therefore this study should provide a deepened understanding of the efficient use of energy. The inconsistent definition of energy efficiency is related to the use of this term for a specific as well as an absolute reduction of energy consumption. Furthermore both static views on efficiency as a status and also dynamic views on efficiency as an improvement of a value compared to a reference number are used. Additional differences occur in the evaluation of the energy use and in the selection of a reference value in a key figure to assess energy efficiency. Moreover the focus of the current general understanding is mainly only on the consumption of energy. All other resources next to the energy input which are needed to provide energy services are not considered even though there are strong interactions and substitution possibilities among these resources. Hence the understanding of energy efficiency is extended in this study by these additional resources which were not considered yet. Based on this extension the efficient use of the resource energy is a result of an optimisation of the relation of these total costs of all resources to the related benefit. To determine the efficient use of energy in the industrial sector, a deeper understanding of the sector and its characteristics is necessary. The industrial sector is the largest consumer of electricity within the EU. Also a quarter of the final energy consumption and about 20 % of the CO2 emissions are related to this sector. Typical for this sector are the heterogeneous and high temperature level of the heat demand and the process emissions which accrue in transformation processes. The subsectors of the industry could be split up into energy intensive subsectors where single production processes dominate the energy consumption, and non-energy intensive subsectors. Ways to reduce the energy consumption in the industrial sector are the use of alternative or improved production or cross cutting technologies and the use of energy saving measures to reduce the demand for useable energy. Based on the analysis within this study, 21 % of the current energy consumption of the industrial sector of the EU and 17 % in Germany could be reduced. Based on the extended understanding of energy efficiency, the model based scenario analysis of the European energy system with the further developed energy system model TIMES PanEU shows that the efficient use of energy at an emission reduction level of 75 % is a slightly increasing primary energy consumption. The primary energy consumption is characterised by a diversified energy carrier and technology mix. Renewable energy sources, nuclear energy and CCS play a key role in the long term. In addition the electricity demand in combination with a strong decarbonisation of the electricity generation is increasing constantly. In the industrial sector the emission reduction is driven by the extended use of electricity, CCS and renewables as well as by the use of improved or alternative process and supply technologies with lower specific energy consumption. Thereby the final energy consumption stays almost on a constant level with increasing importance of electricity and biomass. Both regulatory interventions in the electricity sector and energy saving targets on the primary energy demand lead to higher energy system costs and therewith to a decrease of efficiency based on the extended understanding. The energy demand is reduced stronger than it is efficient and the saving targets lead to the extended use of other resources resulting in totally higher costs. The integrated system analysis in this study points out the interactions between emission reduction and energy saving targets. Some emission reduction pathways like the extended use of nuclear, CCS or biomass and also the extended use of electricity in general are blocked by an energy saving target for the primary energy consumption. There are conflicting interests between the two targets. Especially at higher emission reduction targets energy savings are hard to reach and lead to clearly higher energy system costs. In total it could be shown that an integrated energy system analysis is needed to analysis the whole energy system and the indirect effects of energy use in the industrial sector as well as the interactions with other sectors. Both normative targets and political regulatory interventions in the electricity sector lead to deviations from the efficient use of energy and therewith from the cost optimal pathway.
[en] According to the German act ''Biokraftstoff-Nachhaltigkeitsverordnung'', biofuels must show a CO_2_e_q-reduction compared to the fossil reference fuel (83.8 g CO_2_e_q/MJ_f_u_e_l /Richtlinie 98/70/EG/) of 35 % beginning with 2011. In new plants, which go into operation after the 31.12.2016 the CO_2_e_q-savings must be higher than 50 % in 2017 and higher than 60 % in 2018 /Biokraft-NachV/. The biofuels (methyl ester of rapeseed, bioethanol and biomethane) considered in this study do not meet these requirements for new plants. To comply with these rules new processes must be deployed. Alternative thermochemical generated fuels could be an option. The aim of this work is to evaluate through a technical, ecological and economic analysis (Well-to-Wheel) whether and under what conditions the thermochemical production of Fischer-Tropsch-diesel or -gasoline, hydrogen (H_2) and Substitute Natural Gas (SNG) complies with the targets. Four different processes are considered (fast pyrolysis and torrefaction with entrained flow gasifier, CHOREN Carbo-V "r"e"g"i"s"t"e"r"e"d -gasifier, Absorption Enhanced Reforming (AER-) gasifier). Beside residues such as winter wheat straw and residual forest wood, wood from short-rotation plantations is taken into account. The technical analysis showed that at present status (2010) two and in 2050 six plants can be operated energy-self-sufficient. The overall efficiency of the processes is in the range of 41.5 (Fischer-Tropsch-diesel or -gasoline) and 59.4 % (H_2). Furthermore, it was found that for 2010, all thermochemical produced fuels except the H_2-production from wood from short-rotation plantations in decentralised or central fast pyrolysis and in decentralised torrefactions with entrained flow gasifier keep the required CO_2_e_q-saving of 60 %. In 2050, all thermochemical produced fuels will reach these limits. The CO_2_e_q-saving is between 72 (H_2) and 95 % (Fischer-Tropsch-diesel or -gasoline). When the production costs of the thermochemical produced fuels for 2010 are compared, it becomes evident, that they are not competitive with fossil fuels. The range of costs at the petrol station are between 27.1 (Fischer-Tropsch-diesel- or -gasoline) and 70.7 Euro_2_0_1_0/GJ_f_u_e_l (H_2). With rising CO_2_e_q-costs as well as crude oil and natural gas prices future prospects are getting better for the thermochemical produced fuels.
[en] The German Federal Government published its energy concept in September 2010 with a description of the road into the era of renewable energies. Therefore, the future renewable energy installed in Germany is expected to consist mostly of wind and solar, which are subject to intermittency of supply and significant fluctuations. The growing portion of energy generation by fluctuating sources is turning to a big challenge for the power plant unit commitment and the investment decisions as well. In this thesis, a fundamental electricity market model with combined modeling of these two aspects is developed. This model is subsequently applied to the German electricity market to investigate what kind of power plant investments are indispensable, considering the steadily increasing portion of energy generation from fluctuating sources, to ensure a reliable energy supply in a cost-effective way in the future. In addition, current energy policy in Germany regarding the use of renewable energy and nuclear energy is analyzed.
[en] High spatial and temporal resolution models are essential for answering many questions of air quality management and climate modeling. High-resolution emission models are required to determine the concentration of pollutants using chemical transport models, and to quantify the impacts on health and environment and in particular to develop adequate countermeasures. The aim of this work is to develop methods for the calculation of spatially and temporally high-resolved emissions and to apply these exemplarily on a 1 km x 1 km and hourly resolution for the year 2008 in the EU-27 and EFTA countries. The derivation of methods for the spatial and temporal resolution of emissions with corresponding detailed equations is one of the major improvements that have been carried out in the course of this work. The improvement of the spatial distribution of emissions from the point source relevant sectors like energy supply, industry and waste management is achieved by considering sector specific diffuse emission shares. The progress of the spatial distribution of emissions from households is in particular the development of a fuel type weighted distribution over Europe. Another main focus is the development of the spatial distribution of road transport emissions. Due to the restricted access to traffic count data at the European level, methods have been established to provide reliable emissions on grid level for Europe. The progress in the spatial distribution of agricultural emissions is achieved by the consideration of diffuse shares similar to the other point source relevant sectors like energy supply or industry. In addition to the spatial distribution of the emissions the temporal resolution is a main focus of this work, since the state of knowledge of the temporal resolution of emissions in Europe is still rudimentary. Therefore, it was necessary to develop in particular time curves for the hourly resolution of emissions for the main sectors, namely electricity and heat supply, households, commercial, trade and services, road transport and agriculture. One of the main focuses of the development of temporal profiles was specifically to consider temperature data and other parameters. The derivation of the time profiles requires huge amount of indicator data for each time step. Consequently, the goal for the development of temporal profiles in Europe is to derive temperature dependent equations which are capable of generating sector specific profiles for the present as well as for the future. Based on the developed methods, for the first time the visualization of hourly emissions on a 5 km x 5 km for Europe could be shown. The basis for the visualization was the calculation of hourly emissions at a 1 km x 1 km resolution. Due to the lack of quantitative uncertainty assessments, it was necessary to identify the reasons for the lack of uncertainty analysis at the European level and also to describe the possibilities of a quantitative uncertainty analysis for high resolution emission models. Moreover, on the basis of examples it was possible to describe, how the spatial and temporal uncertainty analysis of high resolution emission models can be carried out.
[en] The transport sector is seen as one of the key factors for driving future energy consumption and greenhouse gas (GHG) emissions. Especially in developing countries, significant growth in transport demand is expected. Gauteng province, as the economic centre of South Africa and transport hub for the whole of southern Africa, is one emerging urban region that faces rapid growth. However, the province is on its way to playing a leading role for supporting ways to adapt to climate change and mitigate GHG emissions. Conversely, there is a lack of scientific research on the promising measures for GHG mitigation in the transport sector. For the rapidly growing transport sector of the province in particular, research is focused primarily on extending and structuring the road infrastructure. Moreover, it is important that the transport sector is considered as part of the whole energy system, as significant contributions to GHG emissions and the associated costs arise from energy supply, provision and conversion. This research is the first application of an integrated energy system model (i.e. the TIMES-GEECO model) for the optimization of the transport sector of Gauteng. Optimizing energy system models allows finding least-cost measures for various scenarios, by considering dependencies and interlinkages in the energy system as well as environmental constraints. To do so, the transport sector and the energy supply sector had to be incorporated into the model application in terms of the characteristics of a developing urban region, which includes all relevant transport modes, vehicle technologies, fuel options, vehicle-to-grid energy storage, the consideration of road types as well as explicit expansions of the public transport system and income-dependent travel demand modelling. Additionally, GHG mitigation options outside the provincial boundaries were incorporated to allow for mitigation at least cost and to consider regional resource availability. Moreover, in TIMES-GEECO, the other demand sectors (such as residential or industry) are also represented. In this thesis, a comprehensive analysis was conducted of alternative fuels, vehicle technologies as well as transport infrastructure for the transport sector of Gauteng. As a result, there are many possibilities of reducing GHG emissions and/or of increasing energy efficiency in the transport sector by using alternative fuels or vehicle technologies. In scenario analysis, it was recognized that under current policies significant growth in both energy consumption and climate emissions can be expected in Gauteng. Marginal GHG abatement cost curves have been calculated, which permit the identification of least-cost mitigation measures for the transport sector under consideration of the whole energy system. It was shown that biofuels from waste cooking oil and cellulosic biomass as well as the substitution of fossil synthetic fuels with crude oil products could result in significant GHG emission reductions. Moreover, hybrid vehicles offer prospects for increasing energy efficiency and reducing GHG emissions at low marginal mitigation costs, where, it was identified that measures should first be applied for vehicles with high annual mileages such as buses, minibuses and heavy-duty vehicles (HDVs). However, the analysis also showed that the transport sector is not the first sector to address for GHG mitigation as significant mitigation potentials with low associated costs lie in the provision of electricity and in the supply of fuels.