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[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] Variable renewable energy sources (VRE) for electricity generation, such as wind and solar power, are subject to inherent output fluctuations. This variability has significant impacts on power system and electricity markets if VRE are deployed at large scale. While on global average, wind and solar power currently supply only a minor share of electricity, they are expected to play a much larger role in the future - such that variability will become a major issue (which it already is in some regions). This thesis contributes to the literature that assesses these impacts the ''system and market integration'' literature. This thesis aims at answering the question: What is the impact of wind and solar power variability on the economics of these technologies? It will be laid out that the impact can be expressed in (at least) three ways: as reduction of value, as increase of cost, or as decrease of optimal deployment. Translating between these perspectives is not trivial, as evidenced by the confusion around the concept of ''integration costs''. Hence, more specifically: How does variability impact the marginal economic value of these power sources, their optimal deployment, and their integration costs? This is the question that this thesis addresses. This study comprises six papers, of which two develop a valuation framework that accounts for the specific characteristics of the good electricity, and the specific properties of wind and solar power versus ''dispatchable'' power plants. Three articles then assess quantitative questions and estimate marginal value, optimal deployment, and integration costs. These estimates stem from a newly developed numerical power market model, EMMA, market data, and quantitative literature reviews. The final paper addresses market design. In short, the principal findings of this thesis are as follows. Electricity is a peculiar economic good, being at the same time perfectly homogenous and heterogeneous along three dimensions - time, space, and lead-time. Electricity's heterogeneity is rooted in its physics, notably the fact it cannot be stored. (Only) because of heterogeneity, the economics of wind and solar power are affected by their variability. The impact of variability, expressed in terms of marginal value, can be quite significant: for example, at 30% wind market share, electricity from wind power is worth 30-50% less than electricity from a constant source, as this study estimates. This value drop stems mainly from the fact that the capital embodied in thermal plants is utilized less in power systems with high VRE shares. Any welfare analysis of VRE needs to take electricity's heterogeneity into account. The impact of variability on VRE cannot only be expressed in terms of marginal value, but also in terms of costs, or in terms of optimal deployment. The mentioned value drop corresponds to an increase of costs by 30-50%, or a reduction of the optimal share by two thirds. These findings lead to seven policy conclusions: 1. Wind power will play a significant role (compared to today). 2. Wind power will play a limited role (compared to some political ambitions). 3. There are many effective options to integrate wind power into power systems, including transmission investments, flexibilizing thermal generators, and advancing wind turbine design. Electricity storage, in contrast, plays a limited role (however, it can play a larger role for integrating solar). 4. For these integration measures to materialize, it is important to get both prices and policies right. Prices need to reflect marginal costs, entry barriers should be tiered down, and policy must not shield agents from incentives. 5. VRE capacity should be brought to the system at a moderate pace. 6. VRE do not go well together with nuclear power or carbon capture and storage - these technologies are too capital intensive. 7. Large-scale VRE deployment is not only an efficiency issue, but has also distributional consequences. Re-distribution can be large and might an important policy driver.
[en] Polarimetric Synthetic Aperture Radar Interferometry (Pol-InSAR) is an active radar remote sensing technique based on the coherent combination of both polarimetric and interferometric observables. The Pol-InSAR technique provided a step forward in quantitative forest parameter estimation. In the last decade, airborne SAR experiments evaluated the potential of Pol-InSAR techniques to estimate forest parameters (e.g., the forest height and biomass) with high accuracy over various local forest test sites. This dissertation addresses the actual status, potentials and limitations of Pol-InSAR inversion techniques for 3-D forest parameter estimations on a global scale using lower frequencies such as L- and P-band. The multi-baseline Pol-InSAR inversion technique is applied to optimize the performance with respect to the actual level of the vertical wave number and to mitigate the impact of temporal decorrelation on the Pol-InSAR forest parameter inversion. Temporal decorrelation is a critical issue for successful Pol-InSAR inversion in the case of repeat-pass Pol-InSAR data, as provided by conventional satellites or airborne SAR systems. Despite the limiting impact of temporal decorrelation in Pol-InSAR inversion, it remains a poorly understood factor in forest height inversion. Therefore, the main goal of this dissertation is to provide a quantitative estimation of the temporal decorrelation effects by using multi-baseline Pol-InSAR data. A new approach to quantify the different temporal decorrelation components is proposed and discussed. Temporal decorrelation coefficients are estimated for temporal baselines ranging from 10 minutes to 54 days and are converted to height inversion errors. In addition, the potential of Pol-InSAR forest parameter estimation techniques is addressed and projected onto future spaceborne system configurations and mission scenarios (Tandem-L and BIOMASS satellite missions at L- and P-band). The impact of the system parameters (e.g., bandwidth, NESZ, ambiguities) and the operation scenario (e.g., temporal decorrelation due to a repeat-pass orbit) is evaluated and discussed with respect to the retrieval of the forest parameters. The study is supported and validated by using repeat-pass Pol-InSAR data at L- and P-band acquired by DLR's E-SAR system over Remningstorp (BioSAR 2007, hemi-boreal forest), Krycklan (BioSAR 2008, boreal forest) and Traunstein (TempoSAR 2008 and 2009, temperate forest) test sites. The simulated spaceborne data sets generated during the BioSAR 2007 campaign are used to carry out the performance analysis.
[en] At the Darmstadt electron linear accelerator the cross sections for the electrofission of 209Bi were measured for electron energies between 24 and 70 MeV, for the separated lead isotopes sup(204,206,207,208)Pb between 38 and 50 MeV. For the determination of the fission thresholds the cross sections were examined by the virtuel photon method using calculations in first Born approximation for the point nucleus with Coulomb wave functions. The analytic functions fitting the fission probability were based on level densities after the Fermi-gas-model. (orig./WL)
[de]Am Darmstaedter Elektronen-Linearbeschleuniger wurden Wirkungsquerschnitte fuer Elektrospaltung von 209Bi bei Elektronenenergien zwischen 24 und 70 MeV und von den getrennten Bleiisotopen sup(204,206,207,208)Pb zwischen 38 und 50 MeV gemessen. Zur Bestimmung der Spaltschwellen wurden die Wirkungsquerschnitte nach der virtuellen Photonenmethode ausgewertet, wobei fuer das virtuelle Photonenspektrum Rechnungen in 1. Bornscher Naeherung fuer den Punktkern mit Coulomb-Wellenfunktionen verwendet wurden. Die in den Berechnungen anzupassende analytische Funktion fuer die Spaltwahrscheinlichkeit basierte auf Niveaudichten nach dem Fermigas-Modell. (orig./WL)
[en] The main barriers for the deployment of renewable energy sources (RES) facilities in the Russian Federation are the lack of political, legislative and regulatory support, low prices for electricity and heat generated from fossil fuels, lack of information for decision makers (e.g. data from research projects) as well as the preference for centralized energy supply schemes. These barriers are contributing to an inadequate investment climate for the implementation of RES facilities. Nevertheless, in some regions of the Russian federation with a potential of RES and a comparatively low degree of economic centralization the situation is different. In the present thesis, the initial conditions for the development of RES potentials for the production of wind, solar and biomass energy in the Krasnodar region (southwestern region of the Russian Federation) are examined using a multi-criteria assessment methodology. For the assessment of the RES potentials at regional scale, the prosed multi-criteria methodology based on the geographic information systems (GIS) and has been complemented by the evaluation and analysis of primary and secondary data as well as economic calculations relevant related to economic feasibility of RES projects. The Krasnodar region has been chosen as model region for other regions in the Russian Federation, Eastern Europe and the former Soviet Union that have unexplored RES potentials but lack sufficient data for the assessment of RES potentials in GIS. An innovative element of the proposed multi-criteria methodology is the combined assessment of the maximum available factors relevant for the economically feasible exploration of RES potentials. These factors included the energy status with the specific features of the energy infrastructure, the energy policy relevant for RES along with the market and economic conditions of the region. The main objectives of the assessment of the RES potentials in the Krasnodar region were (1) to examine and present the energy status and the market conditions in GIS map as the essential conditions for an implementation of GIS facilities; (2) to calculate and present the available yield of wind, solar and biomass energy output through consideration of environmental and land-use restrictions reducing the theoretical resource potential, to the technologically and eventually the economically exploitable share of the initial resource potential; (3) to model energy scenarios and develop specific recommendations for and improved planning of future projects on RES in the study region. The assessment of the theoretical and technological wind energy potential utilized GIS models on extrapolation of wind speed, on suitability class (optimal locations for installation of RES facilities), on wind power density and wind energy estimation. For the assessment of the theoretic and technological solar energy potential, the kriging model, the suitability class model as well as the solar energy estimation model were applied in GIS. The assessment of the biomass energy potential utilized net primary productivity (NPP) and statistic data on organic wastes organic and animal manure using the GIS generic model. Optimal locations for the installation of biomass power plants were identified using network analysis tools in QGIS. The assessment of the technical wind energy potential in the Krasnodar region yielded an electricity production of 23 GWh year-1. Taking into account all the environmental and infrastructural restrictions as well as the current market conditions, the technical energy potential was subjected to reduction to an economically viable share of 0.8 GWh year-1. The total technical solar energy potential amounts to 24 GWh year-1. However, the economically viable share of the solar electricity is 4.5 GWh year-1 due to economic restrictions. The assessment of the biomass energy potential yielded an electricity production from biomass residues of 25 GWh year-1, which, however, was subjected to reduction to 4.7 GWh year-1 due to specific restrictions. The calculated unit (kWh) generation prices for hypothetical energy production facilities in both rural and urban areas of the Krasnodar region were Euros 0.15 (urban-utility scale) and Euros 0.20 (rural-utility scale) for wind electricity, Euros 0.16 (urban PV installations of up to 2 MW) and Euros 0.25 (rural PV installations of up to 1 kW) for solar electricity, and Euros 0.12 (rural-utility scale) and Euros 0.14 (urban-utility scale) for biomass electricity. Compared to the current mean unit generation prices for electricity from conventional energy sources of Euros 0.06 per kWh, the RES electricity prices are not competitive under the current regional and governmental energy policy. The recommendations provided in this thesis aim to highlight relevant support and measures to enable further development of RES potentials in the Krasnodar region. Thus, due to the application of an integrative multifactorial GIS-analysis it was possible to comprehensively estimate the RES potentials in the present work. Detailed and step-by-step analysis of constraints, the energy situation, and the market climate made an indepth feasibility assessment of potential RES projects in the study region. Thus, it was possible to answer the question why, despite the great potential of RES, there are no successful projects in the study region. As a result, reliable information about the RES potential in the region was provided, minimizing risks for investors and policy makers. For other regions, the proposed multi-criteria methodology provides a multi-purpose approach for a complex exploration of RES potentials and their exploitation under specific environmental and economic conditions.
[en] The method described presents a simple way of calculating radiationless rates in the statistical limiting case, while the 2nd part of the paper gives a method that goes beyond this special case. It was shown how the weighted density of state of the final states can be calculated directly and very accurately on the basis of random line widths. The method makes it possible to consider random potential, a random number of modes, and a random energy dependence. (orig.)
[de]Waehrend die beschriebene Methode ein einfaches Verfahren zur Berechnung strahlungsloser Raten im statistischen Grenzfall lieferte, wurde im 2. Teil der Arbeit eine Methode angegeben, die es ermoeglicht, ueber diesen Spezialfall hinauszugehen. Dazu wurde gezeigt, wie die gewichtete Zustandsdichte der Endzustaende unter Einbeziehung beliebiger Linienbreiten direkt und sehr genau berechnet werden kann. Das Verfahren gestattet es, beliebige Potentiale, eine beliebige Anzahl von Moden und eine beliebige Energieabhaengigkeit der Linienbreiten zu beruecksichtigen. (orig.)
[en] Against the background of the long-term goals of the "Energiewende" and the German ratification of the Paris climate protection agreement, both the substitution of fossil fuels like natural gas by renewable energies as well as an increase in energy efficiency in the energy system are indispensable. This requires a radical transformation of the energy system, including the gas system, with associated risks for the actors involved. Political and gas industry decision makers therefore need information on the expected future demand for gas in the German energy mix to plan adequately the expansion of the capital-intensive gas transport infrastructure. These investments often have payback periods of up to several decades. In practice, expansion planning today is carried out regularly with special consideration of import dependency and supply security in network development plans of the responsible transmission system operators. The assumed development of gas demand in the 2016 network development plan, however, does not take into account the objectives of energy system transformation. This thesis develops a methodology to include the “Energiewende” objectives defined well beyond these ten years by 2050 in an assessment of the German gas transport system. Based on a detailed analysis of the current situation of the gas transport system, a scenario analysis is carried out in order to obtain plausible gas demand developments by 2050. From these, relevant grid utilization cases for the gas transport network are derived and investigated using the highly flexible GASOPT load flow model developed within the framework of this work. The suitability of GASOPT for the load flow calculation is demonstrated qualitatively by a back testing calculation of the peak load situation 2015 and quantitatively by a subsequent verification. The results of this thesis show that the gas transport network is only slightly utilized in the long term if the goals of the “Energiewende” are achieved due to a reduction in demand of more than 50 %. The compensation of several failing import routes, e.g. in Eastern Europe or even completely depleted natural gas storage facilities with simultaneous full load operation of gas-fired power plants is technically possible. The full substitution of fossil natural gas by methane produced climate-neutrally using "power-to-gas" is also manageable from the grid side. The long-term economic efficiency of grid sections with low capacity utilization and their rededication to alternative energy sources such as hydrogen can be examined in view of the significant reduction in gas transport demand. Furthermore, the analysis of consequences for the actors involved in the gas transport system shows that the business model of operators of large underground storage facilities in particular will be endangered, as import capacities exceed the required gas withdrawals in the future.
[en] At present almost 43 percent of the waste heat of power plants in the FRG are emitted into surface waters. A deterministical waste heat simulation model for cooling ponds was developed, the results of which were compared with the directly taken water temperatures and the heat release coefficient at the Stever Dam near Haltern (Westfalia). The results of a rough calculation of the maximum cooling capacity of the inland waters of the FRG by means of the heat release coefficient amounted to a total of 336 Wsub(e) by exclusively applying the once-through cooling system. Preliminary tests are presented which are concerned with the effectivity of the heat release on water surfaces by covering them with floating polyhedron-shaped plastic materials to prevent at least part of the waste heat not taken up by rives or wet cooling towers. (GL)
[de]In der BRD werden z.Zt. 43% der KW-Abwaerme an Oberflaechengewaesser abgegeben. Es wurde ein deterministisches Abwaerme-Simulationsmodell fuer Kuehlteile entwickelt dessen Ergebnisse mit direkt an der Stever-Talsperre gemessenen Wassertemperaturen und des Waermeabgabekoeffizienten verglichen werden konnten. Eine ueberschlaegige Berechnung der maximal moeglichen Kuehlleistung bundesdeutscher Binnengewaesser ergab bei ausschliesslicher Anwendung der Durchlaufkuehlung einen Gesamtbetrag von 336 Wsub(e). Vorversuche werden dargestellt, das Waermeabgabevermoegen von Wasseroberflaechen durch Bedeckung mit schwimmenden Kunststoffkoerpern zu 'aktivieren', damit wenigstens ein Teil der Abwaerme nicht in die Fluesse oder Nasskuehltuerme geschickt wird. (GL)
[en] The power supply must integrate in the future an increasing share of renewable energies for the supply of electricity customers to meet the climate protection requirements. The proportion of weather-dependent renewable energy plays a leading role of renewable power supply in the future. These highly volatile provided electricity volumes do not match in base-load power generated amounts, as it has come in the past biogas park and still mostly delivers. It seems necessary that the non-fluctuating production units ''make room'' the wind and PV electricity volumes in the energy system and provide the electricity in phases when the fluctuating renewable energy electricity volumes are not available. In this study, it is determined how the biogas park with its high number of production systems should behave from total cost perspective in the energy system in 2030. It primarily concerns the question whether the base-load electricity production of biogas parks should be changed and made more flexible from the perspective of the overall costs and if so, to what extent.
[de]Die Stromversorgung muss in Zukunft einen stetig steigenden Anteil an Erneuerbarer Energien zur Versorgung der Stromkunden integrieren, um die den Klimaschutzanforderungen zu genuegen. Der Anteil an wetterabhaengigen Erneuerbaren Energien nimmt dabei zukuenftig die tragende Rolle der Erneuerbaren Stromversorgung ein. Diese sehr volatil bereitgestellten Strommengen passen nicht zu in Grundlast erzeugten Strommengen, wie sie in der Vergangenheit der BiogasPark geliefert hat und immer noch groesstenteils liefert. Es scheint erforderlich, dass die nicht fluktuierenden Erzeugungseinheiten den Wind-und PV-Strommengen im Energiesystem ''Platz machen'' und den Strom in Phasen bereitstellen, wenn die fluktuierende Erneuerbaren Energie-Strommengen nicht zur Verfuegung stehen. Im Rahmen dieser Arbeit wird ermittelt, wie sich der BiogasPark mit seiner hohen Zahl an Einzelanlagen im Jahre 2030 im Energiesystem aus Gesamtkostensicht verhalten sollte. Es geht hauptsaechlich um die Frage, ob die Grundlaststromproduktion des BiogasParks aus Sicht der Gesamtkosten veraendert und flexibilisiert werden sollte und wenn ja, in welchem Umfang.
[en] This work deals with a model for the four-channel decay of a system of coupled collective excitations through multidimensional potential barriers. It was used in a simplified form for its application to the fission problem. The simplifications mainly concern the forms of motion of the mother nucleus, the mass complings, the radial barrier, and the post-scission interactions. (orig./LH)
[de]In dieser Arbeit geht es um ein Modell fuer den Vielkanalzerfall eines Systems gekoppelter Kollektivanregungen durch mehrdimensionale Potentialbarrieren. Fuer die Anwendung auf das Spaltproblem wurde es in einer simplifizierten Form verwendet. Die Vereinfachungen betreffen vor allem die Bewegungsformen des Mutterkerns, die Massenkopplungen, die Radialbarriere und die Post-Scission-Wechselwirkungen. (orig.)