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Industrial CO2 use - An overview: Technologies for CO2 utilisation have recently been gaining in importance. Some CO2 uses, such as the production of urea and methanol, are practised on an industrial scale. Many others are being tested. Good progress has been made in the production of plastics and synthetic fuels. The use of carbonised CO2, e.g. for the production of building materials, can lead to the longterm storage of CO2. Synthetic fuels, however, only store the used CO2 for a short time, but prevent the use of fuels made from petroleum. Re-sequestration keeps the CO2 in the cycle. Synthetic methane can play an important role for energy storage and ammonia for the transport of green hydrogen. Overall, however, the contribution of CO2 uses to climate protection is rather limited. To limit global warming, a combination of many climate engineering methods is required in addition to a drastic reduction of global emissions.

Viele Sektoren können durch Elektrifizierung direkt erneuerbare Energien einsetzen. Im Flug und Schwerlastverkehr sowie diversen anderen Anwendungen wird man auch zukünftig auf flüssige synthetische Kraftstoffe angewiesen sein. Kraftstoffe auf Biomassebasis sind schon länger eine Möglichkeit, jedoch ist deren Potential begrenzt (Biomass to Liquid). Durch die Synthese von Wasserstoff und aus der Luft oder indust riellen Prozessen abgeschiedenes Kohlendioxid lässt sich Synthesegas erzeugen, mit dem viele unterschiedliche Kraftstoffe produziert werden können (Power to Liquid). Die direkte Erzeugung von Synthesegas aus Wasser und Kohlendioxid mit Solarkollektoren (Su n to Liquid) ist eine Möglichkeit, die aber noch in der Entwicklung ist.

Hydrogen is a versatile energy carrier which can be produced from variety offeedstocks, stored and transported in various forms for multi-functional end-uses in transportation, energy and manufacturing sectors. Several regional, national and supra-national climate policy frameworks emphasize the need, value and importance of Fuel cell and Hydrogen (FCH) technologies for deep and sector-widedecarbonization. Despite these multi-faceted advantages, familiar and proven FCH technologies such asalkaline electrolysisand proton-exchange membrane fuel cell (PEMFC) often face economic, technical andsocietal barriersto mass-market adoption. There is no single, unified, standardized, and globally harmonized normative definition of costs. Nevertheless, the discussion and debates surrounding plausible candidates and/or constituents integral for assessing the economics and value proposition of status-quo as well as developmental FCH technologies are steadily increasing—Life Cycle Costing (LCC) being one of them, if not the most important outcome of such exercises. To that end, this review article seeks to improve our collective understanding of LCC of FCH technologies by scrutinizing close to a few hundred publications drawn from representative databases—SCOPUS and Web of Science encompassing several tens of technologies for production and select transportation, storage and end-user utilization cases. This comprehensive review forms part of and serves as the basis for the Clean Hydrogen Partnership funded SH2E project, whose ultimate goal is the methodical development a formal set of principles and guardrails for evaluating the economic, environmental and social impacts of FCH technologies. Additionally, the SH2E projects will also facilitate the proper comparison of different FCH technologies whilst reconciling range of technologies, methodologies, modelling assumptions, and parameterization found in existing literature.

The aim of prospective Life Cycle Assessment (LCA) is to assess the ecological impacts of emerging or future technology developments and thus to identify (undesirable) impacts at an early stage in line with the precautionary principle. Various methods can be used to collect foreground Life Cycle Inventory (LCI) data of such technologies that are used for prospective LCA, e.g. scenario techniques, learning curves or expert interviews. For prospective background LCI data futurized ecoinvent databases are available via premise.This contribution shows different approaches to prospective LCA using three technology examples of different TRL. Firstly, future developments of alternatively powered ferries (DBEV, FCEV, BEV) were surveyed by means of expert interviews and workshops. Secondly, learning curves and cumulative capacity curves were used to determine future technological developments for the rotor blades of offshore wind turbines from two manufacturers (Siemens Gamesa, Vestas). Furthermore, premise was applied to achieve a more realistic picture for future environmental impacts. Thirdly, to investigate potential environmental optimization potentials of a magnesium battery (Mg-S) based on expert judgement at very early TRL. Furthermore, the influence of different electric energy grid mix usage for production was analyzed. The technology developments were environmentally assessed by an LCA partly in comparison with conventional or rather status quo technologies, the results of which are presented in this contribution.

The "MCDA for sustainability assessment – insights to Helmholtz Association activities" Working Paper aims to compile and reflect previous and on-going work within the Helmholtz Association related to MCDA, in particular, to present use cases and key methodological aspects. It has a focus on but is not limited to energy technologies and systems and is mainly based on the presentations held at the online workshop “Multi criteria decision analysis for sustainability assessment of energy technologies and systems”. The workshop was organized within the activities of the Helmholtz program ESD Topic 1 "Energy System Transformation" and took place on November 22nd, 2021.

To bring about a successful energy and mobility transition, multifaceted technologies are developed. Hydrogen and Fuel Cell Electric Vehicles (FCEV) cannot only replace fossil fuels and accelerate the electrification of the mobility sector, they also have the advantage of fast refuelling, compared to battery electric vehicles. Next to technical advantages, environmental, economic and social aspects must be considered. Especially the social implications for various stakeholders are often neglected, but no less important. It can affect them to a various extend and in regard to manifold risks and opportunities.Environmental aspects along the whole life cycle of a product, e.g. resource extraction, production, use and end-of-life, can be estimated with the method of Life Cycle Assessment (LCA). Analogously the concept of Social Life Cycle Assessment (S-LCA) addresses social aspects. The goal of this study is to identify possible societal risks and opportunities associated with a production of FCEVs in Germany. In a cradle-to-gate scope, local manufacturing is considered, comprising battery, electric motor, hydrogen tank, glider, and proton exchange membrane fuel cell. By conducting an S-LCA, valuable knowledge about societal hotspots can serve as a basis for further actions.

Reducing greenhouse gas (GHG) emissions in the transport sector is one of the biggest challenges in the German energy transition. Furthermore, sustainable development does not stop with reducing GHG emissions. Other environmental, social and economic aspects should not be neglected. Thus, here a comprehensive sustainability assessment for passenger vehicles is conducted for 2020 and 2050. The discussed options are an internal combustion engine vehicle (ICEV) fuelled with synthetic biofuel and fossil gasoline, a battery electric vehicle (BEV) with electricity from wind power and electricity mix Germany and a fuel cell electric vehicle (FCEV) with hydrogen from wind power. The life cycle-based assessment entails 13 environmental indicators, one economic and one social indicator. For integrated consideration of the different indicators, the MCDA method Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is chosen. For the assessment, a consistent assessment framework, i.e. background scenario and system boundaries, and a detailed modelling of vehicle production, fuel supply and vehicle use are the cornerstones. The BEV with wind power is the most sustainable option in 2020 as well as in 2050. While in 2020, the second rank is taken by the ICEV with synthetic biofuel from straw and the last rank by the FCEV, in 2050 the FCEV is the runner-up. With the help of MCDA, transparent and structured guidance for decision makers in terms of sustainability assessment of motorized transport options is provided.

Progressive development took place within the research area of Social Life Cycle Assessment (S-LCA) recently, e.g. an updated version of the UNEP guidelines was published. One method-based example of the development relates to the use of activity variables, e.g. worker hours. Although it has many advantages, it also brings along shortcomings. One affects the indicators, as for many of them a correlation between their impact and the amount of hours worked does not exist. This makes results difficult to communicate. An alternative approach addressing this issue is using direct quantification and has been introduced in the PSILCA database by GreenDelta.On the example of an S-LCA of the production of a fuel cell electric vehicle (FCEV) opportunities and challenges of this new approach are discussed. The latest versions of the PSILCA databases, for worker hours and raw values respectively, are used. FCEVs have the potential to add to a successful energy and mobility transition. The battery, electric motor, hydrogen tank, glider and fuel cell are included. A reference scale approach following the updated S-LCA guidelines with a cradle-to-gate scope is applied, with Germany being the main manufacturing country. The use- and end-of-life-phases are not part of the study as there is hardly any data for these future technologies available yet.Results of impact categories in the worker hours database have the unit “Medium Risk Hours” of the respective category and hotspots can be identified. In the raw values database indicator results are expressed in their original units after they underwent a normalization procedure, e.g. number of accidents, without workaround over worker hours. This offers the possibility of comparison with other data and is easy to understand. The goal is to analyze the applicability and interpretability of the direct quantification database in comparison to the worker hours database in order to contribute to the further development of the method.

En Alemania, la energía eólica marina (EEM) desempeñará un papel importante en lograr la neutralidadclimática. Las tendencias de desarrollo futuras son ampliar los componentes y aprovechar al máximosus zonas marítimas. Sin embargo, el rendimiento medioambiental de la energía eólica marina dependede muchos factores, como la capacidad nominal del aerogenerador, el diámetro del rotor, la calidad delviento, etc. El análisis de ciclo de vida (ACV) es una metodología que permite evaluar impactosambientales de procesos o servicios, entre ellos conocer el impacto ambiental de la construcción yoperación de turbinas de viento. El ACV tiene un enfoque estático, es decir, brinda una foto instantáneade los impactos ambientales en un tiempo y lugar determinado. Por ello, evaluar el impacto a futuro deturbinas eólicas marinas requiere considerar varios aspectos Este estudio realiza una evaluaciónprospectiva del ciclo de vida (ACV) de las turbinas de viento e identifica los parámetros relevantesrelacionados con la construcción y el funcionamiento de los aerogeneradores. Se recogen datos deinventario según las características futuras de los aerogeneradores (sistema de primer plano). Además,se utilizan bases de datos basadas en la versión futurista de (sistema de fondo). Los parámetros secombinan para describir el mejor y el peor rendimiento medioambiental de las turbinas. Así, seconsidera un escenario optimista, moderado y pesimista para cada año (2030, 2040, 2050). El ACVbasado en escenarios se realiza en el software de código abierto Activity Browser. Los resultadosmuestran que los impactos del cambio climático disminuyen con el tiempo, pasando de 7-17 g CO2-Eq/kWh en 2030 a 4-15 g CO2-Eq/kWh en 2050.

In Germany, offshore wind energy (OWE) will play a significant role in achieving climate neutrality. Future development trends are enlarged components and take maximum advantage of the German maritime zones. However, the environmental performance of OWE depends on many factors, such as wind turbine nominal capacity, rotor diameter, wind quality, etc. This study performs a prospective life cycle assessment (LCA) of OWE and identifies relevant parameters related to the construction and operation of wind turbines. Inventory data is collected according to future characteristics of wind turbines (foreground system). In addition, databases based on futurized version of ecoinvent are used (background system). Parameters are combined to describe the best and worst OWE environmental performance. Thus, an optimistic, moderate and pessimistic scenario for each year (2030, 2040, 2050) are considered. The scenario based LCA is performed in the open-source software Activity Browser. The outcomes show that climate change impacts decline over time, on average ranging from 7-17 g CO2-Eq/kWh in 2030 to 4-15 g CO2-Eq/kWh in 2050.

The glass industry is part of Germany’s energy-intensive industry. Today, mostly fossil energy carriers are used to produce the high temperatures needed, e.g., to melt the raw materials. One option to push defossilisation is the use of green hydrogen in the furnace. The strictest requirements regarding a steady heat supply has the specialty glass production. The hydrogen can be produced on-site in an electrolyzer, using not only the hydrogen for combustion but also the co-produced oxygen in the oxyfuel process. Alternatively, hydrogen can be produced off-site in a large scale electrolyzer to facilitate economy of scale. For transport and distribution of this hydrogen different options are available. Besides conventional high-pressure trailers a rather new option are liquid organic hydrogen carriers (LOHC), which allow hydrogen to be transported and stored at a higher volumetric density and to be treated in the same way as conventional fossil fuels. Temperatures necessary to separate the hydrogen from the LOHC after transport can be provided using waste heat from the glass melt. Another promising future option is the repurposed use of today’s natural gas pipelines. Environmental impacts of this example of the so-called sector coupling – shifting from conventional fossil-based combustion to the use of electrochemically produced hydrogen in combination with a transformation of the German grid mix towards renewable electricity – is being investigated by the means of a Life Cycle Assessment (LCA). The main objective is to evaluate which hydrogen-based solution to produce specialty glass has the least impact on climate change in a time frame from 2020 till 2050. Furthermore, the trade-offs for other environmental impacts are analysed. The results indicate that all hydrogen-based options offer a huge potential to lower greenhouse gas emissions in 2050 compared to today’s fossil-based production. When local conditions permit an on-site hydrogen production this is the best option for hydrogen use in the glass production.

Background: A further increase in renewable energy supply is needed to substitute fossil fuels and combat climate change. Each energy source and respective technologies have specific techno-economic and environmental characteristics as well as social implications. This paper presents a comprehensive approach for prospective sustainability assessment of energy technologies developed within the Helmholtz Initiative “Energy System 2050” (ES2050).Methods: The “ES2050 approach” comprises environmental, economic, and social assessment. It includes established life cycle based economic and environmental indicators, and social indicators derived from a normative concept of sustainable development. The elaborated social indicators, i.e. patent growth rate, acceptance, and domestic value added, address three different socio-technical areas, i.e. innovation (patents), public perception (acceptance), and public welfare (value added).Results: The implementation of the “ES2050 approach” is presented exemplarily and different sustainability indicators and respective results are discussed based on three emerging technologies and corresponding case studies: (1) synthetic biofuels for mobility; (2) hydrogen from wind power for mobility; and (3) batteries for stationary energy storage. For synthetic biofuel, the environmental advantages over fossil gasoline are most apparent for the impact categories Climate Change and Ionizing Radiation—human health. Domestic value added accounts for 66% for synthetic biofuel compared to 13% for fossil gasoline. All hydrogen supply options can be considered to become near to economic competitiveness with fossil fuels in the long term. Survey participants regard Explosion Hazard as the most pressing concern about hydrogen fuel stations. For Li-ion batteries, the results for patent growth rate indicate that they enter their maturity phase.Conclusions: The “ES2050 approach” enables a consistent prospective sustainability assessment of (emerging) energy technologies, supporting technology developers, decision-makers in politics, industry, and society with knowledge for further evaluation, steering, and governance. The approach presented is considered rather a starting point than a blueprint for the comprehensive assessment of renewable energy technologies though, especially for the suggested social indicators, their significance and their embedding in context scenarios for prospective assessments.

Life cycle assessment (LCA) is a standard methodology to assess the environmental impacts of technologies. Many LCA studies prove that wind energy has a low impact on climate change and, thus, is often suggested for the decarbonization of the electricity sectors in different countries. In addition, the LCA studies provide indicators of the environmental performance during the construction, installation, and operation of wind turbines. Yet, these indicators might capture technology development of wind energy meagerly because of the LCAs static approach that depends on the database for background data and is often much older than foreground data. In the meantime, technology evolves and innovates. That is why the integration of LCA indicators into energy systems models is not straightforward. Energy system models provide scenarios that address different visions of the future. Therefore, the environmental aspects of energy systems should grasp technological development, if possible, from two perspectives. First, the life cycle inventory (LCI) should include changes in the foreground according to the future development of the most relevant parameters. Second, the LCI should consider technical and temporal adjustment of background processes, like the market share of resources and utilities. This study focuses on the inventory of wind offshore electricity generation and considers upscaling of wind turbine components. This work applies the scenario development method for wind offshore energy in Germany using the Superstructure approach in the LCA opensource software Activity-Browser, which employs future LCI provided by the Premise initiative. The study sets up scenarios adapted for Germany to reflect expected future trends for wind offshore. The aim is to obtain specific impact indicators and integrate them into an electric system model for assessing optimal operation strategies for future power plant fleets regarding economic, technical, and environmental aspects.

Supplementing material for the CIRP Procedia article to be published in 2022 in the special issue for the 29th CIRP Conference on Life Cycle Engineering.

Green hydrogen for mobility represents an alternative to conventional fuel to decarbonize the transportation sector. Nevertheless, the thermodynamic properties make the transport and the storage of this energy carrier at standard conditions inefficient. Therefore, this study deploys a georeferenced optimal transport infrastructure for four base case scenarios in France and Germany that differs by production distribution based on wind power potential and demand capacities for the mobility sector at different penetration shares for 2030 and 2050. The restrained transport network to the road infrastructure allows focusing on the optimum combination of trucks operating at different states of aggregations and storage technologies and its impact on the annual cost and hydrogen flow using linear programming. Furthermore, four other scenarios with production cost investigate the impact of upstream supply chain cost, and eight scenarios with daily transport and storage optimization analyse the modeling method sensitivity. The results show that compressed hydrogen gas at a high presser level around 500 bar was, on average, a better option. However, at an early stage of hydrogen fuel penetration, substituting compressed gas at low to medium pressure levels by liquid organic hydrogen carrier minimizes the transport and storage costs. Finally, in France, hydrogen production matches population distribution, in contrast to Germany, which suffers from supply and demand disparity.

Electricity is an essential commodity for modern life, which is a driving force for social and economic development. However, electricity generation is not exempt from environmental impacts. In Germany, the energy sector still contributes 30 % to the national greenhouse gas emissions in 2020 (UBA 2021). Even though, the threat of global warming has prompted energy transition policies to ensure a secure, affordable and environmentally compatible electricity supply (BWMi 2019).The path to the energy transition is not unique. Energy system models (ESM) provide scenarios to assess alternatives. Yet, ESM focus on a techno-economic perspective and direct emissions. Therefore, frameworks that couple Life Cycle Assessment (LCA) and ESM have increased interest. Moreover, planetary boundaries (PB) in combination with LCA promise to assess sustainability. The PB concept incorporates an external reference to compare environmental alternatives, and external references are quantitative boundaries that describe the ecological limits of earth system processes. They define a desirable state in which Earth´s system must operate to sustain human development (Rockström, Steffen et al. 2009). This study assesses the sustainability of future electricity mixes based on the PB framework. The study presents Stella, an electricity model for European countries based on Calliope (Jesse, Morgenthaler et al. 2020). This multi-scale energy system modelling framework is python-based and open-source. Preliminary results suggest that wind power as the best compromise in terms of cost and environmental impacts. Fossil fuel technologies add to climate change and contribute considerably to toxic related categories and water eutrophication. From the perspective of PB, biomass is a high contributor to the biochemical flow of nitrogen. Initial results suggest paying attention to technologies that might interfere with the nitrogen cycle.

In order to analyse long-term transformation pathways, energy system models generally focus on economical and technical characteristics. However, these models usually do not consider sustainability aspects such as environmental impacts. In contrast, life cycle assessment enables an extensive estimate of those impacts. Due to these complementary characteristics, the combination of energy system models and life cycle assessment thus allows comprehensive environmental sustainability assessments of technically and economically feasible energy system transformation pathways. We introduce FRITS, a FRamework for the assessment of environmental Impacts of Transformation Scenarios. FRITS links bottom-up energy system models with life cycle impact assessment indicators and quantifies the environmental impacts of transformation strategies of the entire energy system (power, heat, transport) over the transition period. We apply the framework to conduct an environmental assessment of multi-sectoral energy scenarios for Germany. Here, a ‘Target’ scenario reaching 80% reduction of energy-related direct CO2 emissions is compared with a ‘Reference’ scenario describing a less ambitious transformation pathway. The results show that compared to 2015 and the ‘Reference’ scenario, the ‘Target’ scenario performs better for most life cycle impact assessment indicators. However, the impacts of resource consumption and land use increase for the ‘Target’ scenario. These impacts are mainly caused by road passenger transport and biomass conversion.

The study aims then to provide the minimum cost to deploy a transportation system via truck in the German-French border in 2030. This is done by taking into account different hydrogen states of aggregation including compressed gas at different pressure levels, liquefied or chemically bound to a liquid carrier. As primary results, the minimum cost of transporting hydrogen via truck is calculated, taking into account the three different state of aggregation of hydrogen. The levelized cost of transporting hydrogen (LCOTH) includes the transportation, the transformation including liquefaction, compression or chemical bounding and storage depending on the chemical and physical form of hydrogen. As the current market offers a variety of compressed gas trucks (CGT) at different pressure levels, five different pressure levels are taken for the optimization problem to identify the corresponding capacities transported by each of them (at 165.5 bar, 250 bar, 350 bar, 500 bar and 540 bar). Both total capital and operation costs are minimized as a sum of LCOTHs at different hydrogen states of aggregation and as function to the capacity transported over a given distance. The different results are then geographically visualized using the platform QGIS at both sides of the border. On the French side, the region of ‘Grand Est’ is taken with a total population of 5 million. In the other side the three borderer regions Baden-Württemberg, Saarland and Rhineland-Palatinate have a total population of more than 15 million.

Hydrogen mobility is one option for reducing local emissions, avoiding greenhouse gas (GHG) emissions, and moving away from a mainly oil-based transport system towards a diversification of energy sources. As hydrogen production can be based on a broad variety of technologies already existing or under development, a comprehensive assessment of the different supply chains is necessary regarding not only costs but also diverse environmental impacts. Therefore, in this paper, a broad variety of hydrogen production technologies using different energy sources, renewable and fossil, are exemplarily assessed with the help of a Life Cycle Assessment and a cost assessment for Germany. As environmental impacts, along with the impact category Climate change, five more advanced impact categories are assessed. The results show that from an environmental point of view, PEM and alkaline electrolysis are characterized by the lowest results in five out of six impact categories. Supply chains using fossil fuels, in contrast, have the lowest supply costs; this is true, e.g., for steam methane reforming. Solar powered hydrogen production shows low impacts during hydrogen production but high impacts for transport and distribution to Germany. There is no single supply chain that is the most promising for every aspect assessed here. Either costs have to be lowered further or supply chains with selected environmental impacts have to be modified. Hydrogen mobility is one option for reducing local emissions, avoiding greenhouse gas (GHG) emissions, and moving away from a mainly oil-based transport system towards a diversification of energy sources. As hydrogen production can be based on a broad variety of technologies already existing or under development, a comprehensive assessment of the different supply chains is necessary regarding not only costs but also diverse environmental impacts. Therefore, in this paper, a broad variety of hydrogen production technologies using different energy sources, renewable and fossil, are exemplarily assessed with the help of a Life Cycle Assessment and a cost assessment for Germany. As environmental impacts, along with the impact category Climate change, five more advanced impact categories are assessed. The results show that from an environmental point of view, PEM and alkaline electrolysis are characterized by the lowest results in five out of six impact categories. Supply chains using fossil fuels, in contrast, have the lowest supply costs; this is true, e.g., for steam methane reforming. Solar powered hydrogen production shows low impacts during hydrogen production but high impacts for transport and distribution to Germany. There is no single supply chain that is the most promising for every aspect assessed here. Either costs have to be lowered further or supply chains with selected environmental impacts have to be modified.

Industrial hydrogen production via alkaline water electrolysis (AEL) is a mature hydrogen production method. One argument in favor of AEL when supplied with renewable energy is its environmental superiority against conventional fossil-based hydrogen production. However, today electricity from the national grid is widely utilized for industrial applications of AEL. Also, the ban on asbestos membranes led to a change in performance patterns, making a detailed assessment necessary. This study presents a comparative Life Cycle Assessment (LCA) using the GaBi software (version 6.115, thinkstep, Leinfelden-Echterdingen, Germany), revealing inventory data and environmental impacts for industrial hydrogen production by latest AELs (6 MW, Zirfon membranes) in three different countries (Austria, Germany and Spain) with corresponding grid mixes. The results confirm the dependence of most environmental effects from the operation phase and specifically the site-dependent electricity mix. Construction of system components and the replacement of cell stacks make a minor contribution. At present, considering the three countries, AEL can be operated in the most environmentally friendly fashion in Austria. Concerning the construction of AEL plants the materials nickel and polytetrafluoroethylene in particular, used for cell manufacturing, revealed significant contributions to the environmental burden.

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One option to reduce the environmental problems induced by the transport sector is its electrification with fuel cell electric vehicles (FCEV) as they produce locally only water emissions and are much quieter than conventional vehicles with an internal combustion engine. However, for a real environmental benefit of hydrogen not only its usage in a FCEV has to be cleaner. Also its production and distribution has to be taken into account. In particular solar and wind power are often discussed as energy sources for renewable hydrogen production due to its large energy potential all over the world. Due to the unequal local distribution of these energy sources not every country in the world is able to cover their needs of renewable energy on its own, like Japan or Germany. Other regions instead, like North Africa, have very large renewable energy potentials [1]. That is why for Germany next to the production of hydrogen from wind power with electrolysis the import of hydrogen produced with the help of concentrated solar power (CSP) is one future option. By using the high temperatures generated by a CSP plant different hydrogen production options can be of interest, i.e. high temperature electrolysis and thermochemical cycles.Within such a scenario a mayor challenge is the transport: For short and medium distances hydrogen is transported in a gaseous state. The storage density of gaseous hydrogen, however, is quite low. Thus, for longer distances hydrogen is transported as a liquid. However the liquefaction of hydrogen consumes around 30 % of the energy content of hydrogen [2]. As an innovative alternative liquid organic hydro carriers (LOHC) can be used as a carrier fluid. They can be handled much easier than liquid hydrogen with respect to temperature or losses [3]. Against this background the goal of this paper is it to compare three different future hydrogen production and distribution pathways from renewable energies by means of a life cycle assessment: 1. Hydrogen production with alkaline electrolysis powered by wind energy directly at the site of the hydrogen refueling station.2. Hydrogen production with high temperature electrolysis powered by a concentrated solar power plant in North Africa and transported to Germany within liquid organic hydrogen carriers by ship and truck to a hydrogen refueling station.3. Hydrogen production with a thermochemical cycle powered by a concentrated solar power plant (CSP) in North Africa and transported to Germany within liquid organic hydrogen carriers by ship and truck to a hydrogen refueling station.As a fossil reference system the hydrogen production with steam reforming of Natural Gas and its transport by truck to a hydrogen refueling station will be investigated. In all analyzed pathways the functional unit will be 1 kg of hydrogen with 700 bar ready for dispensing at a hydrogen refueling station in Germany. References[1] C. M. Salazar, An Overview of CSP in Europe, North Africa and the Middle East, CSP today, 2008[2] idealhy, Design for Demonstration of Efficient Liquefaction of Hydrogen idealhy: Enabling liquid hydrogen as a means of distribution of low-carbon energy, 2013[3] T. Harada, Ichikawa, H. Takagi, H. Uchida, in; Compendium of Hydrogen Energy Volume 4: Hydrogen Use, Safety and the Hydrogen Economy. M. Ball, A. Basile and T. N. Veziroglu (Ed.), Woodhead Publishing, Cambridge, 2015

Permanent magnets are used in many modern technologies due to their high density of electromagnetic energy. Typically neodymium, praseodymium and dysprosium, three rare earth metals, determine these technical properties. Whereas the demand for rare earth increases constantly, controversial debates emerge in parallel concerning environmental impacts during rare earth production, pressure on market prices due to almost monopolistic production in China, failed attempts to set up western production routes or missing acceptance from local communities at production sites. Therefore, rare earth metals provide an ideal subject for a Life Cycle Sustainability Assessment (LCSA) considering environmental, economic and social aspects.Given the current situation in rare earth production, this study compares three major supply chains from three different rare earth element (REE) deposits: (1) China represents the largest REEs producer worldwide (85%) with its biggest mine in Bayan Obo; (2) Australia is the second largest producer worldwide (8%) and the largest one in the Western World. While mining and beneficiation take place in Australia (Mount Weld mine) the separation is carried out in Malaysia; (3) The Mountain Pass mine in the United States, as a former third largest producer worldwide (3%), is assessed also. Today, the subsequent production of a typical neodymium iron boron magnet (NdFeB) is conducted in China only. Setting up this case study contributes to further develop LCSA methodology more generally, while at the same time giving inside into sustainability aspects of rare earth production in more detail. However, data availability especially for China is one of the biggest problems. For each rare earth supply system a basic process chain is set up and then analysed for the three dimensions, ecology, economy and social aspects using different levels of aggregation. Based on these results different approaches to normalize, weight and aggregate the different indicators of the three dimensions are applied.The results indicate that the supply chain with REE from the USA has the lowest social and environmental impacts as well as low cost. The supply chain from the Chinese REE deposit shows very low costs as well. However, the environmental and social impacts are much higher for this option than for the other two. Only when economic reasons are weighted more important than environmental and social effects China can catch up with the western countries.