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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.
In recent years, many energy scenario studies have proven that a power supply system based on renewable energies (RE) >90 percent is feasible. However, existing scenarios differ significantly in the composition of generation technologies. Some scenarios focus on wind energy in the northern part of Europe, others base on a large utilisation of solar technologies in the south. Apart from the generation capacities, the needed technical flexibilisation strategies such as grid extension, demand flexibilisation and energy storage are generally known and considered in many scenarios. Yet, the impact of different renewable generation strategies on the local utilisation of flexibility options needs to be further assessed. Based upon the BMBF research project RESTORE2050, analyses have been carried out that focus on these interdependencies. The results of the project show that the local utilisation of flexibilisation options depends to a great extent on the technology focus of the long-term renewable expansion strategy. This applies for the spatial flexibilisation as provided by transnational interconnection capacities, especially the ones connecting regions with a surplus of power generation (e.g. GB, Norway and Spain). Another impact of the renewable scenario is seen on the required temporal flexibilisation of electricity generation and demand. In addition, the available options will compete for high utilisation in a future energy system. The differences in the utilisation of these applications, which base on the varying shares of photovoltaic (PV) and wind energy generation, lead to the conclusion that the decision about longterm RE expansion ought to be made very soon in order to avoid inefficient flexibility pathways. Otherwise, if the future RE structure will be kept open, adequate adoption of new flexibility options will be difficult, especially in case of technologies with long lead and realisation time (e.g. new power grids and large scale energy storage devices).
"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.
Energy systems with high shares of renewable electricity are feasible, but require balancing measures such as storage, grid exchange or demand-side management to maintain system stability. The demand for these balancing options cannot be assessed separately since they influence each other. Therefore, a model was developed to analyze these mutual dependencies by optimizing a concerted use of balancing technologies. This model is presented here. It covers the European electricity system in hourly resolution. Since this leads to a large optimization problem, several options for reducing system complexity are presented. The application of the model is illustrated with a case study outlining the effects of pumped hydro storage and controlled charging of electric vehicles in central Europe.
Wind energy that can neither be fed into the grid nor be used regionally must be curtailed. This paper proposes different options to deal with such surplus wind energy amounts in a time horizon until 2020. It assesses their ability to handle the surplus energy in a sustainable way using a multi criteria analysis. The paper bases on a study that was prepared for the Ministry for Climate Protection, Environment, Agriculture, Nature Conservation and Consumer Protection of North Rhine-Westphalia between 2010 and 2012.
Preventing the worst consequences of climate change would require that GHG emissions be reduced to levels near zero by the middle of the century. To respond to such a daunting challenge, we need to rethink and redesign the currently highly energy-dependent infrastructures of industrial societies and particularly the urban infrastructures to become low- or even zero-carbon cities. Sustainable urban infrastructures need technology. In this paper focused on Western European Cities, we discuss a wide set of technologies in the fields of building, energy and transport infrastructures that can significantly contribute to a reduction of energy and/or GHG emissions and are already available or are in the pipeline. Based on the review of a recent study for the city of Munich, we then present how a mix of these technologies could reduce CO2-emissions by up to 90% for the metropolis of 1.3 million inhabitants and that this strategy could be economically attractive despite a high initial investment.
All of the residential buildings of a city like Munich could be entirely redesigned for EUR 200 per inhabitant annually, which is about one third of an average annual natural gas bill.
The reduction of greenhouse gas (GHG) emissions by energyintensive industries to a net zero level is a very ambitious and complex but still feasible challenge, as recent studies show for the EU level. "Industrial Transformation 2050" by Material Economics (2019) is of particular relevance, as it shows how GHG-neutrality can be achieved in Europe for the sectors chemicals (plastics and ammonia), steel and cement, based on three main decarbonisation strategies. The study determines the resulting total demands for renewable electricity, hydrogen and for the capture and storage of CO2 (CCS). However, it analyses neither the regional demand patterns that are essential for the required infrastructure nor the needed infrastructure itself.
Against this background the present paper determines the regional distribution of the resulting additional demands for electricity, hydrogen and CCS in Europe in the case that the two most energy and CCS intensive decarbonisation strategies of the study above will be realised for the existing industry structure. It explores the future infrastructure needs and identifies and qualitatively assesses different infrastructure solutions for the largest industrial cluster in Europe, i.e. the triangle between Antwerp, Rotterdam and Rhine-Ruhr. In addition, the two industrial regions of Southern France and Poland are also roughly examined.
The paper shows that the increase in demand resulting from a green transformation of industry will require substantial adaptation and expansion of existing infrastructures. These have not yet been the subject of infrastructure planning. In particular, the strong regional concentration of additional industrial demand in clusters (hot spots) must be taken into account. Due to their distance from the high-yield but remote renewable power generation potentials (sweet spots), these clusters further increase the infrastructural challenges. This is also true for the more dispersed cement production sites in relation to the remote CO2 storage facilities. The existing infrastructure plans should therefore be immediately expanded to include decarbonisation strategies of the industrial sector.
The production of green hydrogen in Germany is more competitive than expected compared to imports. This is the key finding of a meta-analysis conducted by the Wuppertal Institute on behalf of the North Rhine-Westphalia Association for Renewable Energies (Landesverband Erneuerbare Energien NRW).
The hydrogen study focuses primarily on the year 2030 and beyond - and confirms the advantages of green hydrogen produced in Germany from domestic renewable energies, especially when the evaluation is viewed from a holistic system perspective.
Considering the enormous ecological and economic importance of the transport sector the introduction of alternative fuels - together with drastic energy efficiency gains - will be a key to sustainable mobility, nationally as well as globally. However, the future role of alternative fuels cannot be examined from the isolated perspective of the transport sector. Interactions with the energysystem as a whole have to be taken into account. This holds both for the issue of availability of energy sources as well as for allocation effects, resulting from the shift of renewable energy from the stationary sector to mobile applications. With emphasis on hydrogen as a transport fuel for private passenger cars, this paper discusses the energy systems impacts of various scenarios introducing hydrogen fueled vehicles in Germany. It identifies clear restrictions to an enhanced growth of clean hydrogen production from renewable energy sources (RES). Furthermore, it points at systems interdependencies that call for a priority use of RES electricity in stationary applications. Whereas hydrogen can play an increasing role in transport after 2030 the most important challenge is to exploit short–mid-term potentials of boosting car efficiency.
Flexible, system-oriented operating strategies are becoming increasingly important in terms of achieving a climate-neutral energy system transformation. Solid-oxide electrolysis (SOEC) can play an important role in the production of green synthesis gas from renewable energy in the future. Therefore, it is important to investigate the extent to which SOEC can be used flexibly and which feedback effects and constraints must be taken into account. In this study, we derived a specific load profile from an energy turnaround scenario that supports the energy system. SOEC short-stacks were operated and we investigated the impact that the load profile has on electrical stack performance and stack degradation as well as the product gas composition by means of Fourier-transform infrared spectroscopy. The stacks could follow the grid-related requirement profiles of secondary control power and minute reserves very well with transition times of less than two minutes per 25% of relative power. Only short-term disturbances of the H2/CO ratio were observed during transitions due to the adjustment of feed gases. No elevated degradation effects resulting from flexible operation were apparent over 1300 h, although other causes of degradation were present.
The CO2 utilisation is discussed as one of the future low-carbon technologies in order to accomplish a full decarbonisation in the energy intensive industry. CO2 is separated from the flue gas stream of power plants or industrial plants and is prepared for further processing as raw material. CO2 containing gas streams from industrial processes exhibit a higher concentration of CO2 than flue gases from power plants; consequentially, industrial CO2 sources are used as raw material for the chemical industry and for the synthesis of fuel on the output side. Additionally, fossil resources can be replaced by substitutes of reused CO2 on the input side. If set up in a right way, this step into a CO2-based circular flow economy could make a contribution to the decarbonisation of the industrial sector and according to the adjusted potential, even rudimentarily to the energy sector.
In this study, the authors analyse potential CO2 sources, the potential demand and the range of applications of CO2. In the last chapter of the final report, they give recommendations for research, development, politics and economics for an appropriate future designing of CO2 utilisation options based upon their previous analysis.
Distributed cogeneration units are flexible and suited to providing balancing power, thereby contributing to the integration of renewable electricity. Against this background, we analysed the technical potential and ecological impact of CHP (combined heat and power) systems on the German minutes reserve market for 2010, 2020 and 2030. Typical CHP plants (from 1 to 2800 kWel) were evaluated in relation to typical buildings or supply cases in different sectors. The minutes reserve potential was determined by an optimisation model with a temporal resolution of 15 min. The results were scaled up to national level using a scenario analysis for the future development of CHP. Additionally, the extent to which three different flexibility measures (double plant size/fourfold storage volume/emergency cooler) increase the potential provision of balancing power was examined. Key findings demonstrate that distributed CHP could contribute significantly to the provision of minutes reserve in future decades. Flexibility options would further enhance the theoretical potential. The grid-orientated operating mode slightly increases CO2 emissions compared to the heat-orientated mode, but it is still preferable to the separate generation of heat and power. However, the impacts of a flexible mode depend greatly on the application and power-to-heat ratio of the individual CHP system.