Exergy-based Planning and Thermography-based Monitoring for energy efficient buildings - Progress Report (KIT Scientific Reports ; 7632)

Designing and monitoring energy efficiency of buildings is vital since they account for up to 40% of end-use energy. In this study, exergy analysis is investigated as a life cycle design tool to strike a balance between thermodynamic efficiency of energy conversion and economic and environmental costs of construction. Quantitative geo-referenced thermography is proposed for monitoring and quantitative assessment via continued simulation and parameter estimation during the operating phase

Life cycle-based environmental impacts of energy system transformation strategies for Germany: Are climate and environmental protection conflicting goals?

In the development of climate-friendly energy system transformation strategies it is often ignored that environmental protection encompasses more than climate protection alone. There is therefore a risk of developing transformation strategies whose climate friendliness comes at the expense of higher other environmental impacts. Consequently, an assessment of environmental impacts of energy system transformation strategies is required if undesired environmental side effects of the energy system transformation are to be avoided and transformation strategies are to be developed that are both climate and environmentally friendly. In this paper, ten structurally different transformation strategies for the German energy system were re-modeled (in a harmonized manner). Five of these scenarios describe pathways for a reduction of direct, energy related CO$_2$ emissions by 80%, the other five by 95%. Life cycle-based environmental impacts of the scenarios were assessed by coupling the scenario results with data from a life cycle inventory database focusing on energy and transport technologies. The results show that the transformation to a climate-friendly energy system reduces environmental impacts in many impact categories. However, exceptions occur with respect to the consumption of mineral resources, land use and certain human health indicators, which could increase with decreasing CO$_2$ emissions. The comparison of environmental impacts of moderately ambitious strategies (80% CO$_2$ reduction) with very ambitious strategies (95% CO$_2$ reduction) shows that there is a risk of increasing environmental impacts with increasing climate protection, although very ambitious strategies do not necessarily come along with higher environmental impacts than moderately ambitious strategies. A reduction of environmental impacts could be achieved by a moderate and – as far as possible – direct electrification of heat and transport, a balanced technology mix for electricity generation, by reducing the number and size of passenger cars and by reducing the environmental impacts from the construction of these vehicles

Environmental Sustainability Assessment of Multi-Sectoral Energy Transformation Pathways: Methodological Approach and Case Study for Germany

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

Elastic Tensor of YNi_2B_2C

The complete elastic tensor of YNi_2B_2C was determined by application of the resonant ultrasound spectroscopy technique to a single-crystal sample. Elastic constants were found to be in good agreement with partial results obtained from `time-of-flight' measurements performed on samples cut from the same ingot. From the measured constants, the bulk modulus and Debye temperature are calculated.Comment: 5 pages, 3 figure

Diffusivities of linear unsaturated ketones and aldehydes in compressed liquid ethanol

For the accurate design, optimization and simulation of chemical processes limited by mass transfer kinetics it is important the knowledge of transport properties, namely, diffusion coefficients, D12. In this work, the D12 values of six unsaturated linear ketones (i.e., propanone, butanone, propan-2-one, propan-3-one, hexan-2-one and hexan-3-one) and three unsaturated linear aldehydes (i.e., butanal, pentanal and hexanal) in (compressed) liquid ethanol were measured at temperatures from 303.15 K to 333.15 K and pressures up to 150 bar. The D12 values of ketones are in the range of 1.28 × 10−5 – 2.89 × 10−5 cm2 s−1 and of the aldehydes are between 1.39 × 10−5 and 2.68 × 10−5 cm2 s−1. The general trends of D12 regarding temperature, pressure, Stokes-Einstein coordinate, and free volume are presented and discussed. The diffusivities of the various ketones position isomers and aldehyde/ketone isomers were statistically compared, being possible to conclude that the former ones exhibit indistinguishable diffusivities while different values appear for aldehydes/ketones isomers. Finally, five models and a machine learning algorithm from the literature were tested to predict/correlate the new data. It is suggested that the TLSM model should be the preferred approach for D12 prediction of linear unsaturated aldehydes and ketones in liquid compressed ethanol.publishe