Zukünftige Energie- und Industriesysteme
Using natural gas for fuel releases less carbon dioxide per unit of energy produced than burning oil or coal, but its production and transport are accompanied by emissions of methane, which is a much more potent greenhouse gas than carbon dioxide in the short term. This calls into question whether climate forcing could be reduced by switching from coal and oil to natural gas. We have made measurements in Russia along the world's largest gas-transport system and find that methane leakage is in the region of 1.4%, which is considerably less than expected and comparable to that from systems in the United States. Our calculations indicate that using natural gas in preference to other fossil fuels could be useful in the short term for mitigating climate change.
Based on different current long-term energy scenarios the paper discusses the future perspectives of hydrogen in the German energy system as a representative example for the development of sustainable energy systems. The scenario analysis offers varying outlines of the future energy system that determine the possible role of hydrogen. The paper discusses the possibilities of expanding the share of renewable energy and the resulting prospects for establishing clean hydrogen production from renewable energy sources. Emphasis is given to the questions of an ecologically efficient allocation of limited renewable energy resources that can only be assessed from asystems analysis perspective. Findings from recent studies for Germany reveal a strong competition between the direct input into the electricity system and an indirect use as fuel in the transport sector. Moreover, the analysis underlines the paramount importance of reducing energy demand as the inevitable prerequisite for any renewable energy system.
Mit Inkrafttreten des Kyoto-Protokolls am 16.2.2005 gelten für Deutschland und die meisten anderen Industrieländer völkerrechtlich bindende Minderungsziele für die 6 im Kyoto-Protokoll erfassten Treibhausgase. Damit erlangt eine durchaus kontrovers diskutierte Klimaschutzstrategie, die auf eine stärkere Umstellung der Energienutzung von Öl und Kohle auf mehr Erdgas setzt, zusätzlich an Bedeutung. Der nachfolgende Beitrag setzt sich mit der Klimabilanz des Erdgases unter Berücksichtigung der gesamten Prozesskette auseinander. Insbesondere werden neue Messergebnisse aus Russland dargestellt (Wuppertal Institut 2004), die zeigen, dass die dem Export von russischem Erdgas nach Deutschland zuzuordnenden indirekten Emissionen nur etwa ein Viertel der bei der Erdgasverbrennung entstehenden direkten Emissionen betragen. Damit bleibt Erdgas auch unter Berücksichtigung der indirekten Emissionen in Russland der fossile Energieträger mit den mit Abstand geringsten Treibhausgasemissionen.
The role of hydrogen in long run sustainable energy scenarios for the world and for the case of Germany is analysed, based on key criteria for sustainable energy systems. The possible range of hydrogen within long-term energy scenarios is broad and uncertain depending on assumptions on used primary energy, technology mix, rate of energy efficiency increase and costs degression ("learning effects"). In any case, sustainable energy strategies must give energy efficiency highest priority combined with an accelerated market introduction of renewables ("integrated strategy"). Under these conditions hydrogen will play a major role not before 2030 using natural gas as a bridge to renewable hydrogen. Against the background of an ambitious CO2-reduction goal which is under discussion in Germany the potentials for efficiency increase, the necessary structural change of the power plant system (corresponding to the decision to phase out nuclear energy, the transformation of the transportation sector and the market implementation order of renewable energies ("following efficiency guidelines first for electricity generation purposes, than for heat generation and than for the transportation sector")) are analysed based on latest sustainable energy scenarios.
Because of high efficiency, low environmental impacts and a potential role in transforming our energy system into a hydrogen economy, fuel cells are often considered as a key technology for a sustainable energy supply. However, the future framing conditions under which stationary fuel cells have to prove their technical and economic competitiveness are most likely characterised by a reduced demand for space heating, and a growing contribution of renewable energy sources to heat and electricity supply, which both directly limit the potential for combined heat and power generation, and thus also for fuelcells. Taking Germany as a case study, this paper explores the market potential of stationaryfuelcells under the structural changes of the energy demand and supply system required to achieve asustainable energy supply. Results indicate that among the scenarios analysed it is in particular a strategy oriented towards ambitious CO2-reduction targets, which due to its changes in the supply structure is in a position to mobilise a market potential that might be large enough for a successful fuel cell commercialisation. However, under the conditions of a business-as-usual trajectory the sales targets of fuel cell manufacturers cannot be met.
The Russian natural gas industry is the world's largest producer and transporter of natural gas. This paper aims to characterize the methane emissions from Russian natural gas transmission operations, to explain projects to reduce these emissions, and to characterize the role of emissions reduction within the context of current GHG policy. It draws on the most recent independent measurements at all parts of the Russian long distance transport system made by the Wuppertal Institute in 2003 and combines these results with the findings from the US Natural Gas STAR Program on GHG mitigation options and economics.
With this background the paper concludes that the methane emissions from the Russian natural gas long distance network are approximately 0.6% of the natural gas delivered. Mitigating these emissions can create new revenue streams for the operator in the form of reduced costs, increased gas throughput and sales, and earned carbon credits. Specific emissions sources that have cost-effective mitigation solutions are also opportunities for outside investment for the Joint Implementation Kyoto Protocol flexibility mechanism or other carbon markets.
For the option of “carbon capture and storage”, an integrated assessment in the form of a life cycle analysis and a cost assessment combined with a systematic comparison with renewable energies regarding future conditions in the power plant market for the situation in Germany is done. The calculations along the whole process chain show that CCS technologies emit per kWh more than generally assumed in clean-coal concepts (total CO2 reduction by 72-90% and total greenhouse gas reduction by 65-79%) and considerable more if compared with renewable electricity. Nevertheless, CCS could lead to a significant absolute reduction of GHG-emissions within the electricity supply system. Furthermore, depending on the growth rates and the market development, renewables could develop faster and could be in the long term cheaper than CCS based plants. Especially, in Germany, CCS as a climate protection option is phasing a specific problem as a huge amount of fossil power plant has to be substituted in the next 15 years where CCS technologies might be not yet available. For a considerable contribution of CCS to climate protection, the energy structure in Germany requires the integration of capture ready plants into the current renewal programs. If CCS retrofit technologies could be applied at least from 2020, this would strongly decrease the expected CO2 emissions and would give a chance to reach the climate protection goal of minus 80% including the renewed fossil-fired power plants.
Der Ölpreis wird von zahlreichen Faktoren beeinflusst. Die OPEC spielt bei der Preisbildung derzeit nur eine geringe Rolle. Ein Peak Oil wird die Ölpreise stark beeinflussen und zahlreiche Ausweichdynamiken in Gang setzen, die in ihrer Struktur und Quantität bisher jedoch meist unverstanden sind. Ein ökonomischer Ansatz zu deren Bewertung greift aufgrund vorliegender nicht-ökonomischer Hemmnisse zu kurz. Eine Folge von Rohstoffverknappungen ist eine steigende Energieunsicherheit auf globaler Ebene. Daher ist ein grundsätzlicher Umbau der heutigen Versorgungsstrukturen geboten, um in Zukunft besser gegen strukturelle Unsicherheiten gerüstet zu sein.
Die Vision einer klimafreundlichen zukünftigen energetischen Nutzung von Wasserstoff ist untrennbar mit dessen Erzeugung auf der Basis von regenerativer Energie verknüpft. Für einen Übergangszeitraum kann der Rückgriff auf anderweitig in Industrieprozessen erzeugten Wasserstoff einschließlich vorhandener Infrastrukturelemente sinnvoll sein. Nordrhein-Westfalen bietet hierfür mit dem Rhein-Ruhr-Raum besonders günstige Voraussetzungen und verfügt über zahlreiche Standorte, die sich für energetische Pioniernutzungen von Wasserstoff anbieten. Der Beitrag verknüpft die Erhebung der verfügbaren Wasserstoffmengen in NRW mit der Modellierung des Aufbaus einer Wasserstoffinfrastruktur in NRW und stellt dabei die besondere Ausgangslage des Bundeslandes heraus.
It is now widely recognized that effective communication and demand-side policies for alternative energy require sound knowledge of preferences and determinants of demand of the public and consumers. To date, public attitudes towards new transport technologies have been studied under very different conceptual frameworks. This paper gives an overview of the various conceptual frameworks and methodologies used, where four main approaches can be distinguished: general attitudinal surveys, risk perception studies, non-market economic valuation studies, and other approaches such as those based on semiotic theory. We then review the findings of the recent literature on acceptance, attitudes and preferences for hydrogen and fuelcell end-use technologies, focusing on vehicles. These studies are then contrasted with related research into alternative fuel vehicles. The paper finally discusses the main trends in research and avenues for further work in this field. We recommend, among other things, the use of approaches that build knowledge and familiarity with the technology prior to the exploration of attitudes, and the set up of studies that take a whole-systems perspective of hydrogen technologies and that look at hydrogen in the context of other competing clean technologies.
Renewable energy can become the major energy supply option in low-carbon energy economies. Disruptive transformations in all energy systems are necessary for tapping widely available renewable energy resources. Organizing the energy transition from non-sustainable to renewable energy is often described as the major challenge of the first half of the 21st century. Technological innovation, the economy (costs and prices) and policies have to be aligned to achieve full renewable energy potentials, and barriers impeding that growth need to be removed. These issues are also covered by IPCC's special report on renewable energy and climate change to be completed in 2010. This article focuses on the interrelations among the drivers. It clarifies definitions of costs and prices, and of barriers. After reviewing how the third and fourth assessment reports of IPCC cover mitigation potentials and commenting on definitions of renewable energy potentials in the literature, we propose a consistent set of potentials of renewable energy supplies.
Mit dem Kernenergieunfall im japanischen Fukushima im März 2011 ist die Diskussion über das Für und Wider der Nutzung der Kernenergie für die Stromerzeugung in Deutschland neu entbrannt. Die Frage nach den Auswirkungen eines beschleunigten Ausstiegs aus der Kernenergienutzung auf die Entwicklung der Strompreise in Deutschland bildete in den vergangenen Monaten einen Schwerpunkt der öffentlichen Diskussion. Allerdings halten nicht alle Aussagen, die hierzu veröffentlicht wurden, einer kritischen Analyse stand, was zum Teil auch an zugrunde liegenden politischen Motiven gelegen haben mag. Eine Untersuchung fundierter Studien und ausgewählter Stellungnahmen zeigt, dass sich die befürchteten kurzfristigen Preiseffekte in ü̈berschaubaren Grenzen halten werden.
The study presents the results of an integrated assessment of carbon capture and storage (CCS) in the power plant sector in Germany, with special emphasis on the competition with renewable energy technologies. Assessment dimensions comprise technical, economic and environmental aspects, long-term scenario analysis, the role of stakeholders and public acceptance and regulatory issues. The results lead to the overall conclusion that there might not necessarily be a need to focus additionally on CCS in the power plant sector. Even in case of ambitious climate protection targets, current energy policy priorities (expansion of renewable energies and combined heat and power plants as well as enhanced energy productivity) result in a limited demand for CCS. In case that the large energy saving potential aimed for can only partly be implemented, the rising gap in CO2 reduction could only be closed by setting up a CCS-maximum strategy. In this case, up to 22% (41 GW) of the totally installed load in 2050 could be based on CCS. Assuming a more realistic scenario variant applying CCS to only 20 GW or lower would not be sufficient to reach the envisaged climate targets in the electricity sector. Furthermore, the growing public opposition against CO2 storage projects appears as a key barrier, supplemented by major uncertainties concerning the estimation of storage potentials, the long-term cost development as well as the environmental burdens which abound when applying a life-cycle approach. However, recently, alternative applications are being increasingly considered–that is the capture of CO2 at industrial point sources and biomass based energy production (electricity, heat and fuels) where assessment studies for exploring the potentials, limits and requirements for commercial use are missing so far. Globally, CCS at power plants might be an important climate protection technology: coal-consuming countries such as China and India are increasingly moving centre stage into the debate. Here, similar investigations on the development and the integration of both, CCS and renewable energies, into the individual energy system structures of such countries would be reasonable.
The energy potential of agricultural residues in Tanzania has so far not been evaluated and quantified sufficiently. Moreover, the scientific basis for estimations of the sustainable potential of wastes and residues is still very limited. This paper presents an attempt to evaluate the theoretical and technical potential of residues from the sisal sector in Tanzania with regards to energy recovery through anaerobic digestion. The characteristics and availability of sisal residues are defined and a set of sustainability indicators with particular focus on environmental and socio-economic criteria is applied. Our analysis shows that electricity generation with sisal residues can be sustainable and have positive effects on the sustainability of sisal production itself. All sisal residues combined have an annual maximum electricity potential of 102 GW h in 2009, corresponding to up to 18.6 MW of potential electric capacity installations. This estimated maximum potential is equivalent to about 3 % of the country's current power production. Utilizing these residues could contribute to meeting the growing electricity demand and offers an opportunity for decentralized electricity production in Tanzania.
Die Entscheidung für ein von volatilen Erzeugungsquellen dominiertes Stromsystem stellt an die Stabilisierung des Systems neue Anforderungen. Zugleich bieten sich neue Optionen. Die bisherige Asymmetrie, nach der für die Stabilisierung die Kraftwerksseite verantwortlich sei, ist überkommene Praxis, deswegen auch heute habituell naheliegend, aber vermutlich nicht länger effizient. Die im Titel genannten nachfrageseitigen Ausgleichsoptionen (SE & DSM) bieten sich an. Im Beitrag wird deren Potential abgeschätzt. In vier Gestaltungsfeldern wird zudem gefragt, ob die bislang von der Politik gegebenen rechtlichen Mandate konsequent SE & DSM als Option berücksichtigen. Das Ergebnis ist viermal (weitgehende) Fehlanzeige.
At current primary steel production levels, the iron and steel industry will fail to meet the 80% emission reduction target without introduction of breakthrough technologies (Wörtler et al., 2013: 19). The current research analyses the technical and economical long-term potential of innovative primary steel production technologies in Germany throughout 2100. Techno-economic models are used to simulate three innovative ore-based steelmaking routes verses the reference blast furnace route (BF-BOF). The innovative routes in focus are blast furnace with CCS (BF-CCS), hydrogen direct reduction (H-DR), and iron ore electrolysis (EW). Energy and mass flows for the production of one tonne of crude steel (CS) are combined with hypothetical price, cost, and revenue data to evaluate the production routes economically, technically, and environmentally. This is a purely theoretical analysis and hence further external factors that may influence practical implementation or profitability are not considered.
Different future developments are considered by using three scenarios, representing an ambitious, a moderate, and a conservative transformation of the German energy sector. In general, looking into the future bares various uncertainties which should be reflected in a suitable manner.
According to the present scenario analysis, chances are that with rising prices for coal and CO2 allowances BF-BOF and even BF-CCS become unprofitable by mid-century. With a high share of renewable energy sources and high prices for CO2 allowances, H-DR and EW become economically attractive in the second half of the current century, when BF-based routes are long unprofitable. Energy and raw material efficiency is significantly higher for H-DR and EW and furthermore, the 80% reduction target by 2050 can be achieved in the ambitious scenario. However, high investment costs and high dependency on electricity prices prohibit a profitable implementation before 2030–2040 without further subsidies. EW is the most energy and resource efficient production route. Since continuous electricity is needed for the continuous operation, the electricity costs are 20–40% higher than for H-DR (with high-capacity hydrogen storage units). Even though hydrogen production implies efficiency losses compared to the EW route, the decoupling of hydrogen production from continuous operation of the steel plant through hydrogen storage offers the opportunity to use cheap excess renewable electricity. This makes the H-DR economically and environmentally the most attractive route and provides a crucial contribution to stabilize the grid and to store excess energy in a 100% renewable energy system.
In recent decades, better data and methods have become available for understanding the complex functioning of cities and their impacts on sustainability. This review synthesizes the recent developments in concepts and methods being used to measure the impacts of cities on environmental sustainability. It differentiates between a dominant trend in research literature that concentrates on the accounting and allocation of greenhouse gas emissions and energy use to cities and a reemergence of studies that focus on the direct and indirect material and resource flows in cities. The methodological approaches reviewed may consider cities as either producers or consumers, and all recognize that urban environmental impacts can be local, regional, or global. As well as giving an overview of the methodological debates, we examine the implications of the different approaches for policy and the challenges these approaches face in their application on the field.
Technologischer Wandel ist wichtig für die Umsetzung und den Erfolg der Energiewende, deswegen strebt die Bundesregierung mit ihrer Politik auch eine positive Innovationswirkung an. Doch welche Auswirkungen hat der politisch angestoßene Wandel des Energiesystems wirklich und welche Dynamiken werden durch ihn induziert? Eine aktuelle Studie untersucht die Sicht auf die Energiepolitik und Innovationsaktivitäten in der Energiewirtschaft und Energietechnologie-Branche. Sie zeigt die durch die Energiewende getriebenen Innovationsdynamiken, aber auch Schwierigkeiten und Herausforderungen für Politik und Unternehmen auf.