Open Access

To save energy and reduce environmental impacts, new technologies towards a development of a sustainable ‘greener’ economy are needed. The main opportunity to improve sustainability by reducing emissions is within the transport sector. More than 90% of all goods worldwide are transported by ships. Particularly maritime ships using heavy fuel oil and marine gas oil play a major role. The total fuel consumption of shipping in 2016 was about 250 m t (domestic ca. 50 m t, international shipping ca. 200 m t). The vast portion of the energy consumption of a ship is the need to overcome the drag between ship hull and water—depending on the shape of the vessel and its size up to 90% of total fuel consumption. This means reducing drag helps to save fuel and reduces carbon emissions as well as pollution considerably. Different techniques for drag reduction are known, e.g. the micro-bubble technique or the bulbous bow. We investigated a novel bioinspired technique since 2002: the application of biomimetic surfaces with long-term stable air layers on ship hulls, serving as a slip agent. This technology is based on the Salvinia Effect, allowing a permanent stabilization of air layers under water. In this case study, we analysed the possible savings, which also could be combined with modified micro-bubble technologies.

Die Städte der Dritten Welt orientierten sich in der nachkolonialen Ära wie selbstverständlich am Vorbild der industriegesellschaftlichen Entwicklung und damit an deren energieintensivem Wachstumsmodell. Dadurch wurden und werden sie unvermittelt und ohne Zeit zur Anpassung einer Wachstumsflut ausgesetzt. Ein beispielloser Zuzug überschwemmt die Städte der Dritten Welt und überfordert in kürzester Zeit ihre Infrastruktur.

One of the great societal challenges that we face today concerns the move to more sustainable patterns of energy consumption, reflecting the need to balance both individual consumer choice and societal demands. In order for this ‘energy turnaround’ to take place, however, reducing residential energy consumption must go beyond using energy-efficient devices: More sustainable behaviour and lifestyles are essential parts of future ‘energy aware’ living. Addressing this issue from an HCI perspective, this paper presents the results of a 3-year research project dealing with the co-design and appropriation of a Home Energy Management System (HEMS) that has been rolled out in a living lab setting with seven households for a period of 18 months. Our HEMS is inspired by feedback systems in Sustainable Interaction Design and allows the monitoring of energy consumption in real-time. In contrast to existing research mainly focusing on how technology can persuade people to consume less energy (‘what technology does to people’), our study focuses on the appropriation of energy feedback systems (‘what people do with technology’) and how newly developed practices can become a resource for future technology design. Therefore, we deliberately followed an open research design. In keeping with this approach, our study uncovers various responses, practices and obstacles of HEMS use. We show that HEMS use is characterized by a number of different features. Recognizing the distinctive patterns of technology use in the different households and the evolutionary character of that use within the households, we conclude with a discussion of these patterns in relation to existing research and their meaning for the design of future HEMSs.

When developing new ICT systems and applications for domestic environments, rich qualitative approaches improve the understanding of the user's integral usage of technology in their daily routines and thereby inform design. This knowledge will often be reached through in-home studies, strong relationships with the users and their involvement in the design and evaluation process. However, whilst this kind of research offers valuable context insights and brings out unexpected findings, it also presents methodological, technical and organizational challenges for the study design and its underlying cooperation processes. In particular, due to heterogeneous users in households in terms of technology affinity, individual needs, age distribution, gender, social constellations, personal role assignment, project expectations, etc. it produces particular demands to collaborate with users in the design process and thereby exposes a range of practical challenges. The full-day workshop wishes to identify these practical challenges, discuss best practice and develop a roadmap for sustainable relationships for design with users.

Currently, there is a global problem of an increasing need of energy. There will be less fossil fuel, which will be more expensive in the future. The regenerative energies are becoming more and more important. The subject deals the problem of economical feasibility of geothermal energy systems. Its goal is to analyze necesary conditions and aspects of realizing geothermal energy systems in comparison to and competition with traditional energy sources. The geothermal energy recovery is economically advantageous if the investment costs, esp. the drilling costs, could be reduced significantly. It only seems possible to open up a big opportunity for realizing geothermal energy systems by using a rock melt drilling technology, to reduce the investment costs significantly.

The small and remote households in Northern regions demand thermal energy rather than electricity. Wind turbine in such places can be used to convert wind energy into thermal energy directly using a heat generator based on the principle of the Joule machine. The heat generator driven by a wind turbine can reduce the cost of energy for heating system. However the optimal performance of the system depends on the torque-speed characteristics of the wind turbine and the heat generator. To achieve maximum efficiency of operation both characteristics should be matched. In the article the condition of optimal performance is developed and an example of the system operating at maximum efficiency is simulated.

Nach jetzigen Projektionen wird Afrika als einziger Kontinent das UN-Milleniumsziel einer ausreichenden Wasserversorgung nicht erreichen. Notwendig ist eine umfangreiche Analyse des Wasser-Sektors der afrikanischen Staaten, um Ursachen zu ermitteln und entsprechende Handlungsempfehlungen abzuleiten. Im Mittelpunkt der vorliegenden Untersuchung steht eine länderübergreifende und -vergleichende Analyse der Kosten, Tarifstrukturen und der Subventionspraxis der Wasserversorgungsbetriebe in Sub-Sahara Afrika. Dazu wird ein entsprechendes Bewertungs- und Benchmarkingsystem aufgestellt, das anhand ökonomischer Leistungsprinzipien und -indikatoren eine unternehmensund sektorspezifische Analyse ermöglicht und darüber hinaus die Voraussetzungen für einen internationalen Vergleich schafft.