• Energy Research
• 7. Clean energy close
• 11. Sustainability close
• AT close

AbstractWe develop a mining technology statistical model showing that even environmentally sustainable mining can be still very profitable. We put constraints on mining activities for elevated levels of particulate matters (eg, PM2.5 and PM10) in the air. We show that upper quantiles (eg, 95%) of productivity slightly decrease with respect to maximal number of failures, and this high‐productivity feature is robust with respect to variation of underlying statistical parameters. We illustrate the model on two currently active mining sites, the Chuquicamata copper mine in Chile and the opencast coal mine Libouš in the Czech Republic. Two generic working scenarios have been obtained. We show that, under very realistic conditions for both countries, the Czech Republic and Chilean mining companies can regulate mining activities for high thresholds of air pollutants without a substantial loss of productivity. Sensitivity analysis with respect to parameters is provided.

Mit der vorliegenden Arbeit werden die Emissionen eines Biomasseheizwerkes der Firma URBAS messtechnisch erfasst. Mit diesen Istwerten wird ein Vergleich mit der vorhandenen Literatur gezogen, um eine Reduktion der NOx-Abgaswerte erreichen zu k��nnen. Dazu wird in der einschl��gigen Literatur der theoretische Hintergrund recherchiert, analysiert und es werden m��gliche L��sungswege dargestellt. Das Hauptaugenmerk dieser Arbeit liegt im Feststellen von Prim��rma��nahmen zur Vermeidung von Emissionen. Im Ausblick auf zuk��nftige Entwicklungen wird theoretisch auf die Sekund��rma��nahmen eingegangen. Der Praxisteil dieser Arbeit beinhaltet die Erfassung, Aufbereitung und den Vergleich von messtechnischen Daten einer Anlage der Firma URBAS. Diese sind die Grundlage f��r die Festlegung von m��glichen Prim��rma��nahmen. With the paper in hand the emissions of a biomass heating plant manufactured by the company URBAS are technical measured. These actual values will be compared with values from literature to be able to reach a significant reduction of NOx-emissions. In addition the theoretical background is investigated at corresponding literature, by analysing and showing possible solutions. The main focus of the paper is to lock primary tasks in prevention of emissions. About secondary tasks is only talked theoretically due to prospective developments. The praxis part of the paper includes the coverage, the preparation and the comparison from technical measured data of a plant by company URBAS. These are the basis for the settling of possible primary tasks.

Overhead lines are essential components of high voltage power systems worldwide. The performance of this network element is important for a save and reliable transmission of electrical energy. The load capability of a line is related basically to the line design itself and takes centre stage of the economic operation whereas the sag behaviour and the technical condition of the conductor and their components are more related to the line and network safety. Based on this situation overhead line monitoring systems are actually under discussion in many committees worldwide. This auxiliary equipment for overhead power lines helps to evaluate the actual transfer capability and/or to increase the system reliability. Therefore, a number of systems using different measuring methods and monitoring techniques are available on the market. More or less all methods are based on physical data and process information to achieve a suitable output to control the line stress. One of these methods is called the Weather Parameter Method, which uses local metrological weather data and system load information to estimate the conductor temperature. In a research project running over years an overhead line monitoring system was set up in cooperation with the Austrian transmission utility APG. After these years of experience a number of information and data based on the principle of the Weather Parameter Method is available and gives the scientific basement for this contribution. Three observation stations are collecting data all over the year; two stations are at a 220 kV overhead line and one station at the open air test field of the IHS in Graz in use. This contribution focuses on the coherences of the different parameters collected for the evaluation of the conductor temperature and it is not the main goal to discuss the improved performance by using a thermal management system, as mentioned in many other papers. By the knowledge of the punch-through of significant parameters in combination with the appearance probability a more accurate scheduling of the utilisation of the line under observation will be possible. A well prepared processing of many significant parameters for an overhead line monitoring system and a scientific approach based on some years of practical experience is presented in this contribution.

Abstract Aerogel based insulation plaster has the potential to facilitate the thermal retrofit of historic buildings as its deployment can accommodate the requirements of historical preservation. Thereby, the thermal resistance of historical facades can be increased while maintaining their appearance. The present contribution includes the results of a long-term empirical examination of aerogel containing plaster systems especially for historic buildings under real conditions. In the course of this study, multiple test fields with aerogel insulation plaster were applied to the external walls of an existing room in a university building. Thereby different finishing coatings as well as variations with and without reinforcement mesh were considered. Over a period of three years, external and internal environmental parameters as well as hygro-thermal conditions (temperature, moisture concentration, heat flux) at multiple layers within the test fields were monitored. Moreover, the external appearance of the test fields was regularly captured via observation and photographic documentation. The measured data provided the basis to compare the actual thermal transmittance of the test fields with calculation results based on declared material properties. In addition, the results facilitate the comparison of the different solutions. Specifically, the results suggest a promising thermal performance level (in view of considerably lower U-values) as compared to conventional plaster products. Furthermore, the findings document the role of the finishing layer’s composition in view of the occurrence of potential cracks in the facade.

Abstract A recent article in this journal claimed to assess the socio-technical potential for onshore wind energy in Europe. We find the article to be severely flawed and raise concerns in five general areas. Firstly, the term socio-technical is not precisely defined, and is used by the authors to refer to a potential that others term as merely technical. Secondly, the study fails to account for over a decade of research in wind energy resource assessments. Thirdly, there are multiple issues with the use of input data and, because the study is opaque about many details, the effect of these errors cannot be reproduced. Fourthly, the method assumes a very high wind turbine capacity density of 10.73 MW/km2 across 40% of the land area in Europe with a generic 30% capacity factor. Fifthly, the authors find an implausibly high onshore wind potential, with 120% more capacity and 70% more generation than the highest results given elsewhere in the literature. Overall, we conclude that new research at higher spatial resolutions can make a valuable contribution to wind resource potential assessments. However, due to the missing literature review, the lack of transparency and the overly simplistic methodology, Enevoldsen et al. (2019) potentially mislead fellow scientists, policy makers and the general public.

The building sector is one of the highest energy consumers in Austria. The potential to save energy in existing buildings is very high. Current Austrian policy incentives encourage home owners to renovate buildings to meet the European requirements, reduce energy consumption, and reduce CO2 emissions. Nevertheless, there are often discrepancies between the measured and calculated energy consumption results despite efforts to take parameters into account such as the exact geometry and thermal properties of the building, energy demand for hot water, heating, cooling, ventilation systems, and lighting in the planning phase for selecting the best reconstruction option. To find the answer to this problem, many buildings are carefully investigated with the help of measurements, interviews, and simulations. This paper presents the analysis and results of the investigation of the impact of lifestyle on the energy demand of a single family house. The impact on energy performance of the most important parameters was observed by systematically changing parameters such as changing from a decentralized to a centralized heating system, considering various technologies and fuels for producing electricity and heat, use of renewable energy sources. Different occupant behaviours were changed systematically. The effects of these measures are analysed with respect to primary energy use, CO2 emissions and energy costs. The results of these investigations show that the lifestyle and occupants’ living standard is mainly responsible for the differences between the calculated and measured energy consumption.

AbstractThe ERA-Net SES project Regional Renewable Energy Cells (R2EC) [1] aims at developing a scalable system for decentralized, interacting ‘energy cells’ with a high concentration of locally generated renewable energy. ‘Energy cells’ are essentially Renewable Energy Communities (ECs) in the European context. The system aims at maximizing the utilization of locally generated renewable energy through Electrical Storage (ES) as well as high-electric applications like e‑heating, Heat Pumps (HPs), and E‑Vehicles (EVs). The system is also designed to interact with other energy cells locally, thus, improving the utilization of locally generated energy.A variety of different adjacent energy cells in three countries, Austria (AT), Belgium (BE), and Norway (NO), are analyzed, and the results are used for the development of regional and renewable energy cell systems. This approach aims at developing tailor-made solutions that meet the different local and regional requirements and the electrical energy demand of the observed energy cells. A unique opportunity is created, as the three countries are at varying levels of regional development in the field of energy communities, and the regional requirements and conditions differ significantly. A comprehensive investigation of the technical and economic viability of the ECs in the three regions is conducted on a simulation level. The technical simulation results show an increased self-consumption of individual users and the overall cell in all of the observed testbeds, while the economic analysis shows economic benefits at varying levels in each of the observed testbeds. The implemented R2EC system ascertains both technical and economic viability in the observed testbeds.

Selective catalytic reduction based on urea water solution as ammonia precursor is a promising method for the NOx abatement form exhaust gasses of mobile diesel engine units. It consists of injecting the urea-water solution in the hot flue gas stream and reaction of its products with the NOx over the catalyst surface. During this process flue gas enthalpy is used for the urea-water droplet heating and for the evaporation of water content. After water evaporates, thermolysis of urea occurs, during which ammonia, a known NOx reductant, and isocyanic acid are generated. The uniformity of the ammonia before the catalyst as well as ammonia slip to the environment are important counteracting design requirements, optimization of which is crucial for development of efficient deNOx systems. The aim of this paper is to show capabilities of the developed mathematical framework implemented in the commercial CFD code AVL FIRE®, to simulate physical processes of all relevant phenomena occurring during the SCR process including chemical reactions taking part in the catalyst. First, mathematical models for description of SCR process are presented and afterwards, models are used on the 3D geometry of a real SCR reactor in order to predict ammonia generation, NOx reduction and resulting ammonia slip. Influence of the injection direction and droplet sizes was also investigated on the same geometry. The performed study indicates importance of droplet sizes on the SCR process and shows that counterflow injection is beneficial, especially in terms of minimizing harmful ammonia slip to environment.