Zukünftige Energie- und Industriesysteme
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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.
Generating social practices
(2014)
Changing consumer behaviour is key to reducing the environmental effects of industrialised societies. Social practice theories provide an integrated approach to understanding consumer behaviour. The mechanisms underlying the emergence and diffusion of social practices are however until now poorly understood. This paper presents a conceptual framework and an abstract agent-based simulation model for generating social practices which use and extend approaches from social practice theories. The main results are twofold. First, the simulation model is able to generate social practices, what confirms that the conceptual framework captures relevant elements and processes. Second, a new mechanism for behavioural lock-in is identified that provides additional insights into the widely acknowledged challenge of changing social practices and respective consumption.
Only three days after the beginning of the nuclear catastrophe in Fukushima, Japan, on 11 March 2011, the German government ordered 8 of the country's 17 existing nuclear power plants (NPPs) to stop operating within a few days. In summer 2011 the government put forward a law - passed in parliament by a large majority - that calls for a complete nuclear phase-out by the end of 2022. These government actions were in contrast to its initial plans, laid out in fall 2010, to expand the lifetimes of the country's NPPs.
The immediate closure of 8 NPPs and the plans for a complete nuclear phase-out within little more than a decade, raised concerns about Germany's ability to secure a stable supply of electricity. Some observers feared power supply shortages, increasing CO2-emissions and a need for Germany to become a net importer of electricity.
Now - a little more than a year after the phase-out law entered into force - this paper examines these concerns using (a) recent statistical data on electricity production and demand in the first 15 months after the German government's immediate reaction to the Fukushima accident and (b) reviews the most recent projections and scenarios by different stakeholders on how the German electricity system may develop until 2025, when NPPs will no longer be in operation.
The paper finds that Germany has a realistic chance of fully replacing nuclear power with additional renewable electricity generation on an annual basis by 2025 or earlier, provided that several related challenges, e.g. expansion of the grids and provision of balancing power, can be solved successfully. Already in 2012 additional electricity generation from renewable energy sources in combination with a reduced domestic demand for electricity will likely fully compensate for the reduced power generation from the NPPs shut down in March 2011.
If current political targets will be realised, Germany neither has to become a net electricity importer, nor will be unable to gradually reduce fossil fuel generated electricity. Whether the reduction in fossil fuel use will be sufficient to adequately contribute to national greenhouse gas mitigation targets significantly depends on an active policy to promote electricity savings, continuous efforts to increase the use of renewables and a higher share of natural gas (preferably used in combined heat and power plants) in fossil fuel power generation.
Germany's current efforts to decarbonize its electricity system are analysed. As nuclear power and fossil power plants equipped with carbon capture and storage were ruled out in 2011, renewable electricity generation (RES) together with electricity savings are the primary focus for achieving decarbonization. Germany aims to have RES account for at least 80% of its electricity by 2050. Achieving renewable generation needs strong political support and regulatory provisions for its market integration. Four main technical and regulatory challenges are the maintenance of a steady and efficient expansion of RES, the provision of balancing capacities, the realization of the targeted electricity savings, and the smart adaptation of the transport and distribution grid. An overview of the existing and planned regulatory provisions for decarbonization are described, and some gaps identified, particularly with regard to the overall management of the process, the inclusion of electricity savings and the interference of Germany's decarbonization strategies with neighbouring countries. Policies that both accelerate grid expansion and direct RES expansion should immediately be put in place and can be supported by a targeted mobilization of balancing capacities. Electricity savings are a significant and cost-efficient strategy for low-carbon electricity. Policy relevance: Germany is actively converting its national electricity system towards a fully renewable one. As renewable electricity has reached about a quarter of total consumption, a number of technical and regulatory challenges arise. Current discussions and plans are described for the four main challenges: maintaining and optimizing high investment rates into RES generation technologies, providing balancing capacities, reducing demand, and adapting the grid to the changing needs. Policy recommendations for these four tasks highlight the need to intensify electricity demand reduction and also consider the potential interactions between the German electricity system and its neighbouring countries.
The 2011 Japanese earthquake and tsunami, and the consequent accident at the Fukushima nuclear power plant, have had consequences far beyond Japan itself. Reactions to the accident in three major economies Japan, the UK, and Germany, all of whom were committed to relatively ambitious climate change targets prior to the accident are examined. In Japan and Germany, the accident precipitated a major change of policy direction. In the UK, debate has been muted and there has been essentially no change in energy or climate change policies. The status of the energy and climate change policies in each country prior to the accident is assessed, the responses to the accident are described, and the possible impacts on their positions in the international climate negotiations are analysed. Finally, the three countries' responses are compared and some differences between them observed. Some reasons for their different policy responses are suggested and some themes, common across all countries, are identified. Policy relevance: The attraction of nuclear power has rested on the promise of low-cost electricity, low-carbon energy supply, and enhanced energy independence. The Fukushima accident, which followed the Japanese tsunami of March 2011, has prompted a critical re-appraisal of nuclear power. The responses to Fukushima are assessed for the UK, Germany, and Japan. Before the accident, all three countries considered nuclear as playing a significant part in climate mitigation strategies. Although the UK Government has continued to support nuclear new build following a prompt review of safety arrangements, Japan and Germany have decided to phase out nuclear power, albeit according to different timescales. The factors that explain the different decisions are examined, including patterns of energy demand and supply, the wider political context, institutional arrangements, and public attitudes to risk. The implications for the international climate negotiations are also assessed.
The Low Carbon Future Cities (LCFC) project aims at facing a three dimensional challenge by developing an integrated city roadmap balancing: low carbon development, gains in resource efficiency and adaptation to climate change. The paper gives an overview of the first outcomes of the analysis of the status quo and assessment of the most likely developments regarding GHG emissions, climate impacts and resource use in Wuxi - the Chinese pilot city for the LCFC project. As a first step, a detailed emission inventory following the IPCC guidelines for Wuxi has been carried out. In a second step, the future development of energy demand and related CO2 emissions in 2050 were simulated in a current policy scenario (CPS). In parallel, selected aspects of material and water flows for the energy and the building sector were analyzed and modeled. In addition, recent and future climate impacts and vulnerability were investigated. Based on these findings, nine key sectors with high relevance to the three dimensions could be identified. Although Wuxi's government has started a path to implement a low carbon plan, the first results show that, for the shift towards a sustainable low carbon development, more ambitious steps need to be taken in order to overcome the challenges faced.
A cost-minimizing electricity market model was used to explore optimized infrastructures for the integration of renewable energies in interconnected North African power systems until 2030. The results show that the five countries Morocco, Algeria, Tunisia, Libya and Egypt could together achieve significant economic benefits, reaching up to EUR 3.4 billion, if they increase power system integration, build interconnectors and cooperate on joint utilization of their generation assets. Net electricity exports out of North Africa to Europe or Eastern Mediterranean regions, however, were not observed in the regime of integrated electricity markets until 2030, and could only be realized by much higher levels of renewable energy penetration than currently foreseen by North African governments.
Both focus group discussions and information-choice questionnaires (ICQs) have previously been used to examine informed public opinions about carbon dioxide capture and storage (CCS). This paper presents an extensive experimental study to systematically examine and compare the quality of opinions created by these two research techniques. Depending on experimental condition, participants either participated in a focus group meeting or completed an ICQ. In both conditions participants received identical factual information about two specific CCS options. After having processed the information, they indicated their overall opinion about each CCS option. The quality of these opinions was determined by looking at three outcome-oriented indicators of opinion quality: consistency, stability, and confidence. Results for all three indicators showed that ICQs yielded higher-quality opinions than focus groups, but also that focus groups did not perform poor in this regard. Implications for the choice between focus group discussions and ICQs are discussed.
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.
If the current energy policy priorities are retained, there may be no need to focus additionally on carbon capture and storage (CCS) in the power plant sector of Germany. This applies even in the case of ambitious climate protection targets, according to the results of the presented integrated assessment study. These cover a variety of aspects: Firstly, the technology is not expected to become available on a large scale in Germany before 2025. Secondly, if renewable energies and combined heat and power are expanded further and energy productivity is enhanced, there is likely to be only a limited demand for CCS power plants, as a scenario analysis of CCS deployment in Germany shows. Thirdly, cost analysis using the learning curve approach shows that the electricity generation costs of renewable electricity approach those of CCS power plants. This leads to the consequence that, from 2020, several renewable technologies may well be in a position to offer electricity at a cheaper rate than CCS power plants. In addition, a review of new life cycle assessments for CO2 separation in the power plant sector indicates that the greenhouse gas emissions from 1 kW h of electricity generated by first-generation CCS power plants could only be reduced by 68 % to 87 % (95 % in individual cases). Finally, a cautious, conservative estimate of the effective German CO2 storage capacity of approximately 5 billion tonnes of CO2 is calculated, including a fluctuation range yielding values between 4 and 15 billion tonnes of CO2. Therefore, the total CO2 emissions caused by large point sources in Germany could be stored for 12 years (basic value) or for 8 or 33 years (sensitivity values).