• Energy Research

Abstract This paper compares the sustainability of pressurized alkaline water electrolysis systems operating at different places in Europe (Austria, Germany and Spain). Using a Life Cycle Sustainability Assessment (LCSA) approach, an advanced electrolysis system (6 MW) based on Zirfon membranes is investigated. Results of Life Cycle Assessment, Life Cycle Costing and social Life Cycle Assessment plus subsequent normalizing, weighting, and aggregation in LCSA are assessed. A closer look reveals that the choice of weighting concept has a crucial impact on results. As main outcome, the comparison illustrates that hydrogen production via electrolysis in Germany performs best if weak sustainability (equal weighting of dimensions) is assessed. Using the strong sustainability concept (considering only environmental results) Germany yields worst results mostly due to the environmental impacts of its electricity generation.

In the literature, many studies outline the advantages of agrivoltaic (APV) systems from different viewpoints: optimized land use, productivity gain in both the energy and water sector, economic benefits, etc. A holistic analysis of an APV system is needed to understand its full advantages. For this purpose, a case study farm size of 0.15 ha has been chosen as a reference farm at a village in Niger, West Africa. Altogether four farming cases are considered. They are traditional rain-fed, irrigated with diesel-powered pumps, irrigated with solar pumps, and the APV system. The APV system is further analyzed under two scenarios: benefits to investors and combined benefits to investors and farmers. An economic feasibility analysis model is developed. Different economic indicators are used to present the results: gross margin, farm profit, benefit-cost ratio, and net present value (NPV). All the economic indicators obtained for the solar-powered irrigation system were positive, whereas all those for the diesel-powered system were negative. Additionally, the diesel system will emit annually about 4005 kg CO2 to irrigate the chosen reference farm. The land equivalent ratio (LER) was obtained at 1.33 and 1.13 for two cases of shading-induced yield loss excluded and included, respectively.

Sustainable development as a concept of societal development encompasses some problems that need to be addressed carefully. They relate to overcoming the technical limits of individual systems, reducing environmental impact, social inclusion, green economic progress involving all stakeholders, limiting the impact of human activities, etc. Over the past few years, as a result of the increasingly pronounced climate change, more and more studies are addressing these problems and stress the importance of sustainable development. The key to sustainable development are, therefore, the solutions to the problems currently encountered by various stakeholders, that together contribute to the preservation of the environment for future generations. This is no longer based on the goodwill of individuals, but has become the responsibility of the entire generation. This article presents some examples of the solutions for the problems arising from sustainable development and is an overview of recent scientific achievements in the field of sustainable development that emerged from recent Sustainable Development of Energy, Water and Environment Systems (SDEWES) conferences. As such, it acts as an editorial paper for the virtual special issue of the Journal of Environmental Management, that is dedicated to the SDEWES2017 conference.

Ever since 2002, when the first Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES) was held in Dubrovnik, the SDEWES conferences series has been providing a forum for world-wide scientists and those interested in learning about the sustainability of development, to present research progress and to discuss the state of the art, the future directions and priorities in the various areas of sustainable development. This includes the improvement and dissemination of knowledge on methods, policies and technologies for increasing the sustainability of development, taking into account its economic, environmental and social pillars, as well as methods for assessing and measuring sustainability of development, regarding energy, transport, water, food production and environment systems and their many combinations. SDEWES has maintained high publishing standard as nearly 1100 SDEWES papers are published in special issues of leading scientific journals including "Energy - The International Journal".

AbstractBackgroundIn the twenty-first century, the success story of the Post-World-War-II World has been called into question by climate change and other challenges. De-growth or zero economic growth are discussed as possible solutions for mitigating climate change. The traditional economic growth model is increasingly challenged by the demand for sustained economic growth expressed in United Nations Sustainable Development Goal 8 “sustained economic growth” (UN-SDG 8) and supported by the European Green Deal. The aim of this paper is to contribute to the general understanding of characteristics, effects and challenges of new economic growth ideas as well as their interlinkages with the food–energy–water (FEW) nexus.MethodsTo address these challenges, a stylized dynamic General Equilibrium Model (GEM) was developed, which consists of two countries: an emerging, developing European country A and a developed European country B. Country A is assumed to grow, while country B shrinks. The model is based on artificial data sets. This approach was chosen to prevent the blurring of counterfactual comparison by country-specific effects of economic turbulences such as the Lehman crash or the economic break-in during the Covid-19 pandemic.ResultsThe gross output of the emerging European country increases, whereas the output of the developed European country decreases according to the different growth strategies. The analysis reveals that a constantly widening gap between the emerging and the developed country is created. It can further be shown how this influences the relevant economic indicators (CO2emissions, household budget, trade balance, utility and social welfare).ConclusionsThe analysis of the two-country stylized GE model makes distortions visible: insignificant gaps in the values and development of analyzed economic indicators become prevalent. The welfare gap affects the core of the traditional socio-economic system, because the development of the utility of the households is central for the stability of political processes. A sufficiency and subsistence sector may be an option to even out the welfare losses from the de-growth strategy of the traditional economic system to avoid that the de-growth gaps are perceived by the community as welfare losses which can endanger the realization of UN-SDG 8.

The UN Sustainable Development Goals formulated in 2016 confirmed the sustainability concept of the Earth Summit of 1992 and supported UNEP's green economy transition concept. The transformation of the energy system (Energiewende) is the keystone of Germany's sustainability strategy and of the German green economy concept. We use ten updated energy-related indicators of the German sustainability strategy to analyse the German energy system. The development of the sustainable indicators is examined in the monitoring process by a vector analysis performed in two-dimensional Euclidean space (Euclidean plane). The aim of the novel vector analysis is to measure the current status of the Energiewende in Germany and thereby provide decision makers with information about the strains for the specific remaining pathway of the single indicators and of the total system in order to meet the sustainability targets of the Energiewende. Within this vector model, three vectors (the normative sustainable development vector, the real development vector, and the green economy vector) define the resilience space of our analysis. The resilience space encloses a number of vectors representing different pathways with different technological and socio-economic strains to achieve a sustainable development of the green economy. In this space, the decision will be made as to whether the government measures will lead to a resilient energy system or whether a readjustment of indicator targets or political measures is necessary. The vector analysis enables us to analyse both the government's ambitiousness, which is expressed in the sustainability target for the indicators at the start of the sustainability strategy representing the starting preference order of the German government (SPO) and, secondly, the current preference order of German society in order to bridge the remaining distance to reach the specific sustainability goals of the strategy summarized in the current preference order (CPO).

The United Nations has defined the food-energy-water nexus as a key issue in the green economy process towards sustainable development. The integrated assessment model is used here to frame and study the heterogeneity of the food-energy-water nexus and to manage the food-energy-water nexus in Germany in a social learning and decision-making process. For the integrated assessment of the German food-energy-water nexus sector, a four-phase approach based on the de Ridder method is used to analyse the food-energy-water nexus against the background of the completely revised German sustainability strategy of 2017. In the first step, the integrated assessment problem analysis, the interconnections of the food-energy-water nexus between the natural resources and the socio-economic system are formulated. The new political values and options needed for the management of the food-energy-water nexus sector are revealed in the second research step and it is stressed that justice is the defining ethical norm of the revised German sustainability strategy of 2017, which is the sustainability framework for the German food-energy-water nexus. Thus, inter- and intragenerational justice is also a central issue of the food-energy-water nexus and is integrated with the social discount rate in the food-energy-water measuring concept (Fisher nexus quantity index) presented in the third step. In the final research step of the integrated assessment approach, it is found that the new food-energy-water nexus policy process also needs a ‘culture of reflected numbers’, as Voßkuhle calls it, to ensure a social discourse as a permanent learning process for both the German government and society.