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Reaching the climate goals for the building sector requires to improve insulation and to increase air tightness of buildings in order to minimize heat loss. To achieve these goals and to prevent risks to the health of occupants and damages to the building fabric due to insufficient removal of pollutants and humidity, broad implementation of Mechanical Ventilation and Heat Recovery (MVHR) systems is crucial.
Comparable and up to date figures on the market penetration of MVHR systems across the EU are hardly available. However, figures point to only a small share of residential buildings being currently equipped with such systems (cf. Riviere et al. 2009). For the German building stock the figure is estimated to be below 5% (Händel 2011). The paper presents insights into the reasons for the slow diffusion of HRV technologies in the German building stock. It builds on the results of a recently completed research project whose central aim was to identify actor-specific and structural barriers for the diffusion of efficient ventilation systems in apartment buildings and to examine how these barriers can be addressed.
The analysis is based on 40 semi-structured expert interviews with energy consultants, HVAC craftsmen, and housing companies, as well as guided in-depth interviews with private owners of apartment buildings or apartments that were evaluated by means of qualitative content analysis. Based on the collected data, seven barrier categories were identified, each containing a range of single barriers for the diffusion of efficient ventilation systems within the residential building stock.
Results of the analysis were quantitatively validated by means of online surveys and a household survey among 1,008 households. The paper points out interdependencies within the chain of effects leading up to the investment decision of building owners. Furthermore, based on good practice examples identified within the data collection process, it proposes different measures to address these barriers.
The key objective of this deliverable is to gain insights on and assess how CE is being implemented and R&I is being funded at regional level, e.g., via the RIS3 strategy and Structural Funds. As such it sets the scope for the project and provides the background against which programmes and measures can be understood, assessed, developed and recommended in succinct tasks and work packages. The objective of this report is to provide a concise overview of the current R&I priorities, as expressed in running and newly introduced funding and legislative measures with respect to Circular Economy in European countries and regions.
On the basis of a literature research, this subtask develops a conceptional framework for a common understanding of CE within the project team and for the following work packages and tasks. After a brief introduction into the objectives and the context of a circular economy, a more elaborated look into the necessity of an explicit understanding of CE, the objectives, the spatial perspective of CE and the specific challenges within the CICERONE context will be done, in order to develop a basis for a common understanding within the project context. Circular economy can and has to be understood as an (eco-)innovation agenda. Therefore, the paper investigates the role policy has to play to support innovation for a CE transition, for creating the framework conditions and why CE has also to be build from the ground up. Finally, the paper looks from two perspectives at emerging trends and business models in a CE to sketch next steps towards the transition in a selection of central sectors. Conclusions are drawn on the basis of the insights gained by the preceding chapters.
Urban energy systems have been commonly considered to be socio-technical systems within the boundaries of an urban area. However, recent literature challenges this notion in that it urges researchers to look at the wider interactions and influences of urban energy systems wherein the socio-technical sphere is expanded to political, environmental and economic realms as well. In addition to the inter-sectoral linkages, the diverse agents and multilevel governance trends of energy sustainability in the dynamic environment of cities make the urban energy landscape a complex one. There is a strong case then for establishing a new conceptualisation of urban energy systems that builds upon these contemporary understandings of such systems. We argue that the complex systems approach can be suitable for this. In this paper, we propose a pilot framework for understanding urban energy systems using complex systems theory as an integrating plane. We review the multiple streams of urban energy literature to identify the contemporary discussions and construct this framework that can serve as a common ontological understanding for the different scholarships studying urban energy systems. We conclude the paper by highlighting the ways in which the framework can serve some of the relevant communities.
The earth as we know it can only continue to exist if humanity finds a way to switch to a sustainable use of energy and resources. This work contributes to the research carried out to achieve this goal by improving the coating of adsorptive materials. These are used in heat transformation and drying processes that allow for efficient temperature and humidity control in buildings. A central component of these adsorptive coatings is the binder that acts as "glue" in the manufacturing of the coating. In this work the methods to evaluate binder performance regarding their thermal stability under the process conditions, their mechanical stability and their influence on the adsorptive properties of the coating were established. The coatings have to meet special requirements due to the thermal stresses and low pressure atmosphere they experience in these applications. A selection of silicone binders was then characterized with the established tests according to these requirements. Additionally a selection of inorganic binders was investigated because they allow for the use of high desorption temperatures and thus a high energy efficiency of the process. Out of these binders Silres® MP50E emerged as the most promising one due to very good adsorptive properties of the coating, its good temperature stability and ease of use. While some of the inorganic binders showed very good adsorptive properties and temperature stability the mechanical stability of all inorganic binders was not sufficient for their use in adsorption heat transformation technology. This is the first time that a broad selection of binders was evaluated with regards to adsorptive coatings and the results published in literature. With a suitable binder identified, the next step was to optimize the coating of the heat exchangers in order to work out how to manufacture the most efficient and powerful heat exchangers. Samples with different coating thicknesses were manufactured in small scale and full scale and their adsorption behavior was characterized. It could be shown for the first time that it is possible to increase energy efficiency by improving the mass ration of adsorber to coating and increase the delivered power at the same time. This was shown for small and full scale samples. It was shown that under the corresponding conditions the heat transfer from the coating layer to the adsorber metal substrate is the limiting step in the process. These results can now be used for the planning and construction of adsorbers. With knowledge of a suitable binder and how to coat efficient, powerful adsorbers, the coating process itself was improved to allow for industrial scale manufacturing. A central point here is the ability to control slurry rheology. Out of many rheology additives those that are suited for the application in adsorption heat transformation were identified and their influence on the slurry rheology thoroughly characterized. Additionally the process of slurry preparation could be simplified for several different adsorbents. Here it was shown that the supersonic deagglomeration step is not necessary to prepare a slurry. Extending the possible coating techniques and in addition to the dip coating process used so far, the spray coating of adsorptive coatings was established for the first time in literature. This process is widely used in the industry and allows for easier plugin into existing coating processes. For the coating of high resolution patterns a proof of concept of the screen printing process was carried out.
Digital platforms may yield a host of advantages in putting circular economy into effect. This paper analyses the related chances and discusses requirements of digital platforms for the realization of a circular economy. It specifically points to potential solutions offered by digital platforms for existing barriers. From there it identifies issues that need specific attendance to create economically and ecologically functional platforms. Three economically relevant perspectives are discussed for this: a management perspective, a legislative perspective and a social/systems perspective.
Reflecting trends in the academic landscape of sustainable energy using probabilistic topic modeling
(2019)
Background: Facing planetary boundaries, we need a sustainable energy system providing its life support function for society in the long-term within environmental limits. Since science plays an important role in decision-making, this study examines the thematic landscape of research on sustainable energy, which may contribute to a sustainability transformation. Understanding the structure of the research field allows for critical reflections and the identification of blind spots for advancing this field.
Methods: The study applies a text mining approach on 26533 Scopus-indexed abstracts published from 1990 to 2016 based on a latent Dirichlet allocation topic model. Models with up 1100 topics were created. Based on coherence scores and manual inspection, the model with 300 topics was selected. These statistical methods served for highlighting timely topic trends, differing thematic fields, and emerging communities in the topic network. The study critically reflects the quantitative results from a sustainability perspective.
Results: The study identifies a focus on establishing and optimizing the energy infrastructure towards 100% renewable energies through key modern technology areas: materials science, (biological) process engineering, and (digital) monitoring and control systems. Energy storage, photonic materials, nanomaterials, or biofuels belong to the topics with the strongest trends. The study identifies decreasing trends for general aspects regarding sustainable development and related economic, environmental, and political issues.
Conclusions: The discourse is latently adopting a technology-oriented paradigm focusing on renewable energy generation and is moving away from the multi-faceted concept of sustainability. The field has the potential to contribute to climate change mitigation by optimizing renewable energy systems. However, given the complexity of these systems, horizontal integration of the various valuable vertical research strands is required. Furthermore, the holistic ecological perspective considering the global scale that has originally motivated research on sustainable energy might be re-strengthened, e.g., by an integrated energy and materials perspective. Beyond considering the physical dimensions of energy systems, existing links from the currently technology-oriented discourse to the social sciences might be strengthened. For establishing sustainable energy systems, future research will not only have to target the technical energy infrastructure but put a stronger focus on issues perceivable from a holistic second-order perspective.
Responsible consumption and production is one of the Sustainable Development Goals of the United Nations. To achieve this goal the currently high extraction rates of natural resources, that our economy is based on, needs a transformation of the consumption and production system considering technological as well as social change. One of the promising transition approaches is seen in collaborative consumption with its many facets of socio-cultural innovations and fast growing number of participants and businesses. With a decreasing production of goods, due to a utilisation of underutilised assets, these offers might support an absolute reduction of the global resource use. However, a positive environmental effect depends on the setting and the social practices of such sharing offers and is not sustainable or resource efficient generally. Also, resource efficient practices with a low diffusion potential that stick in a niche offer no leverage to achieve sustainable consumption patterns. Thus, this paper describes a mixed method approach to analyse the resource efficiency and diffusion potential of 20 sharing offers in the area of mobility, housing & travel and everyday objects in Germany. Results show that the overall positive environmental connotation of sharing offers cannot be confirmed. We identified five clusters of offers that are all treated to be differently when it comes to deploying the positive potential and avoid unnecessary societal effort to achieve the mentioned Sustainable Development Goal.