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Integrated systems analysis
(2007)
Biogas and bio-methane that are based on energy crops are renewable energy carriers and therefore potentially contribute to climate protection. However, significant greenhouse gas emissions resulting from agricultural production processes must be considered, mainly resulting from agricultural production processes, as fertilizer use, pesticide etc.
This paper provides an integrated life cycle assessment (LCA) of biogas (i.e. bio-methane that has been upgraded and injected into the natural gas grid), taking into account the processes of fermentation, upgrading and injection to the grid for two different types of biogas plants thus examining the current state of the art as well as new, large-scale plants, operated by industrial players. Not only technical and engineering aspects are taken into account here, but also the choice of feedstock which plays an important role as to the overall ecological evaluation of bio-methane.
The substrates evaluated in this paper - aside from maize - are rye, sorghum, whole-crop-silage from triticale and barley, and the innovative options of agricultural grass (Landsberger Gemenge, a mixture of hairy vetch (vicia villosa), crimson clover (trifolium incarnátum) and Italian ryegrass (lolium multiflorum)) as well as a combination of maize and sunflower.
Technical summary
(2012)
The concept of regime and "flat ontologies" : empirical potential and methodological implications
(2012)
Innovation and diffusion of car-sharing for sustainable consumption and production of urban mobility
(2008)
How can renewable energy sources be efficiently integrated into the North African electricity systems? By using techno-economic modeling methods, this book explores optimized electricity system expansion pathways until the year 2030 for the five North African countries - Morocco, Algeria, Tunisia, Libya and Egypt. The results indicate that renewable energy integration is actually a viable business case for the entire region, if wind and solar capacities are properly planned in conjunction with the conventional generation system and under consideration of the country-specific electricity supply-/demand patterns. Further aspects featured in this publication are the impact of renewable power on the transnational electricity transmission system and the question how decision making processes about renewable energy strategies can be improved in the North African context. The book is a contribution to the scientific literature about energy issues in the Middle East and North Africa (MENA), but also seeks to address political and industrial practitioners concerned with the development of the region's renewable energy future.
The global land area required to meet the German consumption of agricultural products for food and non-food use was quantified, and the related greenhouse gas (GHG) emissions, particularly those induced by land-use changes in tropical countries, were estimated. Two comprehensive business-as-usual scenarios describe the development corridor of biomass for non-food use in terms of energetic and non-energetic purposes. In terms of land use, Germany was already a net importer of agricultural land in 2004, and the net additional land required by 2030 is estimated to comprise 2.5–3.4 Mha. This is mainly due to biofuel demand driven by current policy targets. Meeting the required biodiesel import demand would result in an additional GWP of 23–37 Tg of CO2 equivalents through direct and indirect land-use changes. Alternative scenario elements outline the potential options for reducing Germany's land requirement, which reflect future global per capita availability.
This study provides insight into the feasibility of a CO2 trunkline from the Netherlands to the Utsira formation in the Norwegian part of the North Sea, which is a large geological storage reservoir for CO2. The feasibility is investigated in competition with CO2 storage in onshore and near-offshore sinks in the Netherlands. Least-cost modelling with a MARKAL model in combination with ArcGIS was used to assess the cost-effectiveness of the trunkline as part of aDutch greenhouse gas emission reduction strategy for the Dutch electricity sector and CO2 intensive industry. The results show that under the condition that a CO2 permit price increases from €25 per tCO2 in 2010 to €60 per tCO2 in 2030, and remains at this level up to 2050, CO2 emissions in the Netherlands could reduce with 67% in 2050 compared to 1990, and investment in the Utsira trunkline may be cost-effective from 2020–2030 provided that Belgian and German CO2 is transported and stored via the Netherlands as well. In this case, by 2050 more than 2.1 GtCO2 would have been transported from the Netherlands to the Utsira formation. However, if the Utsira trunkline is not used for transportation of CO2 from Belgium and Germany, it may become cost-effective 10 years later, and less than 1.3 GtCO2 from the Netherlands would have been stored in the Utsiraformation by 2050. On the short term, CO2 storage in Dutch fields appears more cost-effective than in the Utsira formation, but as yet there are major uncertainties related to the timing and effective exploitation of the Dutch offshore storage opportunities.
The paper analyzes a Bolivian region for possible cultivation of the oil plant Jatropha curcas for sustainable biodiesel production in order to replace in part Bolivia's diesel imports. The specific site for this study is located in the dry region of Gran Chaco in Santa Cruz. The aim of this work is to analyse the potential of useable land and resources for sustainable biodiesel production from Jatropha without competition with edibles production using economic, environmental and social criteria. In addition the article introduces Jatropha as one of the preferred oil plants for biodiesel production in several countries and indicates its different uses. The recommendation to cultivate Jatropha for biodiesel production is based on an exploration of the possibility of land use in the selected region and the benefits Jatropha production could offer. In this manner a sustainable cultivation of Jatropha in the region of Gran Chaco is recommended to produce biodiesel and to improve some of the environmental problems facing the region.
We present an approach to simulate climate and energy policy for the EU, using a flexible and modular agent-based modelling approach and a toolbox, called the Energy Modelling Laboratory (EMLab). The paper shortly reviews core challenges and approaches for modelling climate and energy policy in light of the energy transition. Afterwards, we present an agent-based model of investment in power generation that has addressed a variety of European energy policy questions. We describe the development of a flexible model core as well as modules on carbon and renewables policies, capacity mechanisms, investment behaviour and representation of intermittent renewables. We present an overview of modelling results, ongoing projects, a case study on current reforms of the EU ETS, and we show their relevance in the EU context.
Renewables and off-grid rural electrification in developing countries : dimensions and trends
(2005)
Increasing urbanisation and climate change belong to the greatest challenges of the 21st century. A high share of global greenhouse gas emissions are estimated to originate in urban areas (40 % to 78 % according to UN Habitat 2010). Therefore, low carbon city strategies and concepts implicate large greenhouse gas (GHG) mitigation potentials. At the same time, with high population and infrastructure densities as well as concentrated economic activities, cities are particularly vulnerable to the impacts of climate change and need to adapt. Scarce natural resources further constrain the leeway for long-term, sustainable urban development. The Low Carbon Future Cities (LCFC) project aims at tapping this three-dimensional challenge and will develop an integrated strategy / roadmap, balancing low carbon development, gains in resource efficiency and adaptation to climate change. The study focuses on two pilot regions - one in China (Wuxi) and one in Germany (Düsseldorf+) - and is conducted by a German-Chinese research team supported by the German Stiftung Mercator. The paper gives an overview of 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 project developed an emission inventory for Wuxi to identify key sectors for further analysis and low carbon scenarios. The future development of energy demand and related CO2 emissions in 2030 were simulated in the current policy scenario (CPS), using five different sub-models. Selected aspects of Wuxi's current material and water flows were analysed and modelled for energy transformation and the building sector. Current and future climate impacts and vulnerability were investigated. Recent climatic changes and resulting damages were analysed, expected changes in temperature and precipitation in the coming four decades were projected using ensembles of three General Circulation Models. Although Wuxi's government started a path to implement a low carbon plan, the first results show that more ambitious efforts are needed to overcome the challenges faced.
Water is a basis for life and ecosystem health. And water, especially in regions affected by water scarcity, is a highly contested and politicised natural resource. The state-of-the-art in sustainable water resources management requires collaborative approaches that foster the integration of conflicting interests of multiple stakeholders. Achieving integration in complex and contested real life situations however remains a major challenge. Boundary work can facilitate this ambitious goal. This study evolves boundary work science to improve collaboration in the water sector. It develops a framework for boundary work that enables understanding, structuring and approaching barriers for collaborative water resources management. A case study from the Garden Route region, South Africa gives a grounded basis for the conceptual developments and further provides in-depth insights into reasons and obstacles for collaborative water resources management in a contested local case. The case study serves both: An intrinsic analysis of a conflictive case, and conceptual developments to the boundary work framework - tested against local realities.
One of the factors decelerating a further diffusion of the carbon capture and storage (CCS) technology is the public's negative perception of early pilot or demonstration activities in Germany as well as in other countries. This study examined the public perception of CCS in more detail by looking into different options within the CCS chain, i.e. for the three elements capture, transport and storage. This was analyzed using an experimental approach, realized in an online survey with a representative German sample of 1830 citizens. Each participant evaluated one of 18 different CCS scenarios created using three types of CO2 source (industry, biomass, coal), two transport options (pipeline vs. no specification), and three storage possibilities (saline aquifer, depleted gas field, enhanced gas recovery (EGR)).
Overall, we found that the ratings of CCS were neutral on average. However, if the CO2 is produced by a biomass power plant or industry, CCS is rated more positively than in a scenario with a coal-fired power plant. The specifications of transport and storage interacted with each other such that scenarios including EGR or a depleted gas field without mentioning a pipeline were evaluated better than storing it in a saline aquifer or a depleted gas field and mentioning a pipeline as means of transport. Exploratory regression analyses indicate the high relevance of the respective CO2 source in general as well as the perceived importance of this source for Germany.
Technical summary
(2015)
Summary for policymakers
(2012)
"Energiewende", which roughly translates as the transformation of the German energy sector in accordance with the imperatives of climate change, may soon become a byword for the corresponding processes most other developed countries are at various stages of undergoing. Germany's notable progress in this area offers valuable insights that other states can draw on in implementing their own transitions. The German state of North Rhine-Westphalia (NRW) is making its own contribution to achieving the Energiewende's ambitious objectives: in addition to funding an array of "clean and green" projects, the Virtual Institute Power to Gas and Heat was established as a consortium of seven scientific and technical organizations whose aim is to inscribe a future, renewable-based German energy system with adequate flexibility. Thus, it is tasked with conceiving of and evaluating suitable energy path options. This paper outlines one of the most promising of these pathways, which is predicated on the use of electrolytically-produced hydrogen as an energy storage medium, as well as the replacement of hydrocarbon-based fuel for most road vehicles. We describe and evaluate this path and place it in a systemic context, outlining a case study from which other countries and federated jurisdictions therein may draw inspiration.
Sustainable strategies
(2014)
Scenarios for the transition to a sustainable and climate protecting energy system in Germany
(2004)
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.
Industry
(2014)
Understanding the diversifying role of civil society in Europe's sustainability pathway is a valid proposition both scientifically and socially. Civil society organisations already play a significant role in the reality of cities, what remains to be explored is the question: what is the role of civil society in the future sustainability of European cities? We first examine the novelty of new forms of civil society organization based on a thorough review of recent case studies of civil society initiatives for sustainable transitions across a diversity of European projects and an extensive literature review. We conceptualize a series of roles that civil society plays and the tensions they entail. We argue that, civil society initiatives can pioneer new social relations and practices therefore be an integral part of urban transformations and can fill the void left by a retreating welfare state, thereby safeguarding and servicing social needs but also backing up such a rolling back of the welfare state. It can act as a hidden innovator - contributing to sustainability but remaining disconnected from the wider society. Assuming each of these roles can have unintended effects, such as being proliferated by political agendas, which endanger its role and social mission, and can be peeled off to serve political agendas resulting in its disempowerment and over-exposure. We conclude with a series of implications for future research on the roles of civil society in urban sustainability transitions.
How is it possible to increase homeowners' insulation activity? Answering this question is key to successful policies regarding energy-efficient buildings worldwide. In Germany, doubling today's insulation rate of about 1% is an important element for reaching the government's target of an 80% reduction in energy demand in the building sector by 2050.
This thesis uses an agent-based model analysis to improve the understanding of homeowners' insulation activity and to explore new approaches aiming at its increase in Germany. Two agent-based models were developed and utilized. The first model was developed mainly based on insights derived from a structured literature review. The second emerged from the previous one, incorporating the results of an online survey conducted among 275 homeowners.
The results indicate that homeowners' economic means have little influence on their decision to install insulation. Instead, their insulation decision-making is mostly affected by situational factors and their attitudes towards insulation. Situational factors, such as the condition of the building, are important because they initiate homeowners' individual decision-making processes on insulation. The simulation results show that improving homeowners’ attitudes about insulation by providing information has a comparatively low potential for increasing their insulation activity. Out of the policy options this thesis explored, the introduction of an obligation to insulate the walls within one year after change of house ownership was found to have the greatest impact on homeowners' insulation activity.
Insulating existing buildings offers great potential for reducing greenhouse gas emissions and meeting Germany's climate protection targets. Previous research suggests that, since homeowners' decision-making processes are inadequately understood as yet, today's incentives aiming at increasing insulation activity lead to unsatisfactory results. We developed an agent-based model to foster the understanding of homeowners' decision-making processes regarding insulation and to explore how situational factors, such as the structural condition of houses and social interaction, influence their insulation activity. Simulation experiments allow us furthermore to study the influence of socio-spatial structures such as residential segregation and population density on the diffusion of renovation behavior among homeowners. Based on the insights gained, we derive recommendations for designing innovative policy instruments. We conclude that the success of particular policy instruments aiming at increasing homeowners' insulation activity in a specific region depends on the socio-spatial structure at hand, and that reducing financial constraints only has a relatively low potential for increasing Germany's insulation rate. Policy instruments should also target the fact that specific renovation occasions are used to undertake additional insulation activities, e.g. by incentivizing lenders and craftsmen to advise homeowners to have insulation installed.
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.
A number of "roadmapping" activities are being carried out internationally with the aim of planning and facilitating transitions to hydrogen energy systems. However, there is an evident discrepancy between the treatment of quantitative and qualitative information in the majority of roadmapping efforts. Whilst quantitative information is frequently analysed in numerical and computational models, conversely qualitative information tends to be incorporated on a significantly more ad hoc basis. Previous attempts at incorporating qualitative considerations have not usually been systematised. In this paper we present a methodology aimed at increasing the rigour with which qualitative information is treated in hydrogen roadmapping activities. The key changes and actor mapping (KCAM) methodology was developed as the primary qualitative component of the European Hydrogen Energy Roadmap project "HyWays". KCAM, developed from a well known general systems development model, constitutes a means of qualitatively analysing variable hydrogen supply chains that is structured, systematic and flexible.
The establishment of the Leveraging a Climate-neutral Society–strategic Research Network (LCS–RNet) (then named the International Research Network for Low Carbon Societies) was proposed at the Group of Eight (G8) Environment Ministers’ Meeting in 2008. Its 12th annual meeting in December 2021 focused on the discussion on how to transition into a just and sustainable society and how to reduce the risks associated with the transition. This requires comprehensive studies including on the concept of transition, pathways to net-zero societies and how to realise the pathways by collaborating with various stakeholders. This Special Feature provides new insights into sustainability science by linking the scientific knowledge with practical science for the transition through the exploration of studies presented at the annual meeting. Following the opening paper, "A challenge for sustainability science: can we halt climate change?", a wide range of topics were discussed, including practices for sustainable transformation in the Erasmus University, practices in industry, energy transition and international cooperation.
Scientization : putting global climate change on the scientific agenda and the role of the IPCC
(2010)
Since the 1970s, climate change has dominated the international scientific and political agenda. In particular, the foundation of the Intergovernmental Panel on Climate Change at the end of the 1980s played a major role for the further enhancement of efforts in the field of climate change sciences. However, to understand the interaction of the worldwide coordination of climate change sciences as well as the role of the Intergovernmental Panel on Climate Change and its consequences, it is worthwhile to take a look at the self-conception of the Intergovernmental Panel on Climate Change's tasks and work. This paper gives an idea of the history of international climate change science, its representation in public discourse and the role of the Intergovernmental Panel on Climate Change by comprehensively illustrating its tasks, organization and self-image. Furthermore, the article tries to argue that the hitherto accepted concept of science followed within this body fails to integrate the idea of scientific ethics. It can be concluded that the conception of science represented by the Intergovernmental Panel on Climate Change has heavily influenced worldwide attention to climate change, its becoming part of the political agenda as well as the ethical consequences.
The analysis of different global energy scenarios in part I of the report confirms that the exploitation of energy efficiency potentials and the use of renewable energies play a key role in reaching global CO2 reduction targets. An assessment on the basis of a broad literature research in part II shows that the technical potentials of renewable energy technologies are a multiple of today's global final energy consumption. The analysis of cost estimates for renewable electricity generation technologies and even long term cost projections across the key studies in part III demonstrates that assumptions are in reasonable agreement. In part IV it is shown that by implementing technical potentials for energy efficiency improvements in demand and supply sectors by 2050 can be limited to 48% of primary energy supply in IEA's "Energy Technology Perspectives" baseline scenario. It was found that a large potential for cost-effective measures exists, equivalent to around 55-60% of energy savings of all included efficiency measures (part V). The results of the analysis on behavioural changes in part VI show that behavioural dimensions are not sufficiently included in energy scenarios. Accordingly major research challenges are revealed.
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.
Research on sustainability transitions has expanded rapidly in the last ten years, diversified in terms of topics and geographical applications, and deepened with respect to theories and methods. This article provides an extensive review and an updated research agenda for the field, classified into nine main themes: understanding transitions; power, agency and politics; governing transitions; civil society, culture and social movements; businesses and industries; transitions in practice and everyday life; geography of transitions; ethical aspects; and methodologies. The review shows that the scope of sustainability transitions research has broadened and connections to established disciplines have grown stronger. At the same time, we see that the grand challenges related to sustainability remain unsolved, calling for continued efforts and an acceleration of ongoing transitions. Transition studies can play a key role in this regard by creating new perspectives, approaches and understanding and helping to move society in the direction of sustainability.
For parabolic trough power plants using synthetic oil as the heat transfer medium, the application of solid media sensible heat storage is an attractive option in terms of investment and maintenance costs. One important aspect in storage development is the storage integration into the power plant. A modular operation concept for thermal storage systems was previously suggested by DLR, showing an increase in storage capacity of more than 100 %. However, in these investigations, the additional costs needed to implement this storage concept into the power plant, like for extra piping, valves, pumps and control had not been considered. These aspects are discussed in this paper, showing a decrease of levelized energy costs with modular storage integration of 2 to 3 %. In a Life Cycle Assessment (LCA) a comparison of an AndaSol-I type solar thermal power plant [1] with the original two-tank molten salt storage and with a "hypothetical" concrete storage shows an advantage of the concrete storage technology concerning environmental impacts. The environmental impacts of the “hypothetical” concrete based AndaSol-I decrease by 7 %, considering 1 kWh of solar electricity delivered to the grid. Regarding only the production of the power plant, the emissions decrease by 9.5 %.
Participatory scenario processes : a tool for mutually shaping the future and social learning
(2017)
The greenhouse gas balance
(2013)
Natural gas makes an increasing contribution to the European Union's energy supply. Due to its efficiency and low level of combustion emissions this reduces greenhouse gas emissions compared to the use of other fossil fuels. However, being itself a potent greenhouse gas, a high level of direct losses of natural gas in its process chain could neutralise these advantages. Which effect will finally prevail depends on future economical as well as technical developments. Based on two different scenarios of the main influencing factors we can conclude that over the next two decades CH4 emissions from the natural gas supply chain can be significantly reduced, in spite of unfavourable developments of the supply structures. This, however, needs a substantial, but economically attractive investment into new technology, particularly in Russia.
Sustainable energy systems
(2016)