From Circular to Linear? Assessing the Life Cycle Environmental and Economic Sustainability of Steel and Plastic Beer Kegs

In the craft brewing industry, kegging solutions have changed dramatically in recent years. While steel kegs once dominated the draught beer market, single-use plastic kegs have increased in popularity due to their convenience, especially in the craft brewing sector. With the increasing importance of the circular economy and the introduction of policies in Europe to move away from single-use plastic systems, this study aims to assess and compare the sustainability of conventional steel and single-use plastic kegs. The environmental and economic performance are assessed through life cycle assessment and life cycle costing approaches. The results suggest that steel kegs have better environmental performance and life cycle costs. However, these are limited to the local markets, and with larger distances, plastic kegs may become the better option due to their lower weight, suggesting that both kegs are useful in certain situations. This is especially important in countries that have long distances between breweries and their markets. The importance of extending the lifetime of the keg fleet is also highlighted to improve the environmental performance as the results are influenced by the assumption on the lifetime of the steel kegs. To improve the environmental performance of plastic kegs, efficient closed-loop recycling systems should be developed. Careful decision-making is needed to ensure that more sustainable packaging options are chosen for draught beer and that sustainability aspects be taken into account beyond convenience.

Innovative test method for the reliable evaluation of joint sealants in concrete pavements

Joint sealants as indispensable filling systems in jointed plain concrete pavements (JPCP) are permanently exposed to various stresses during their service life, which often leads to a replacement of the sealing after approx. 7 to 10 years. Aside from seasonal unsteady climatic changes, the cyclical stresses caused by traffic and the ageing of joint sealants are especially significant. Considering the rising number of damages that occur within the overall "joint" system, an increased demand for a durable solution is requested as it is a relevant element for the life cycle costs of concrete pavements. In this context, a testing and ageing method was developed which comprises of the entire "joint" system, including the saw-cut concrete joint flanks, the primer as well as the joint sealant. This procedure depicts the decisive scenarios of in-situ stresses and allows the characterization of joint sealants. For this purpose, specimens were subjected to horizontal and vertical loads (static/cyclic) as well as to various ageing effects (temperature conditioning, UV-conditioning and freeze-thaw-cycles). After conditioning, a significant influence of the artificial ageing on the residual strength was observed in the tensile/shear tests. By comparing the artificially aged samples tested in the laboratory with extracted and in-situ aged samples, a reliable correlation was determined. Considering these system tests an initial approach was established which enables the evaluation of joint sealants in both unaged and artificially aged conditions on the basis of scientific parameters and limits.

Local barriers in the efficient use of Green Public Procurement - case of Slovaki

Green public procurement is a voluntary tool through which public procurers can contribute to the objectives of environmental policy. The legal framework and public policy of green procurement is covered by the European Union. The main goal is to contribute to the consideration of environmental characteristics in public purchases as well as environmental management and the life-cycle costs of the goods, services and work. However, the objectives of the legal framework and the policy to promote green public procurement are often not achieved due to the barriers posed by economic practice. The aim of the article is to analyze the local barriers in the effective use of green public procurement in Slovakia. The processing of results is based on the annual evaluation reports to the National Action Plan for Green Public Procurement in Slovakia for 2016-2020. Identified local barriers include financial constraints on contracting authorities and a preference for evaluating contracts based on the lowest price criterion, insufficiently built administrative (personal) capacity to implement green public procurement, fear of discrimination in incorporating environmental criteria into tender documents and subsequent sanctions from control bodies. Last but not least, the voluntary application of green public procurement at regional and local level is also included among the barriers in the efficient use of this tool in practice.

Techno-Economic and Life-Cycle Impact Analysis of Solar Photovoltaic Microgrid Systems for Off-Grid Communities

<p>This thesis proposes Solar Photovoltaic Microgrids (SPMs) for six different remote communities in Nigeria, one from each of the country’s geopolitical zones. The research analysis is presented based on the basic load demand of 24 households within each of the selected communities. The arrangements of the houses are obtained from the community’s layout provided by a building consortium. The study first presents the intended users’ basic energy needs and their daily energy usage. The available solar energy resources of the different locations are also carefully examined, in relation to their disparities, intermittent characteristics and seasonal variations. The research also emphasises the possibility of load growth. With such consideration, more practical electrification solutions can be achieved. The study considers users’ electricity demand growth of 25 to 75% of the baseline value of 175 kWh/d. The photovoltaic microgrid systems are modelled in the DIgSILENT PowerFactory environment. The lengths of the lines running from the electric power plant to the households are obtained from the community’s layout. This information is included in the model, coupled with the solar energy data and the technical configurations of the PV arrays. The effectiveness of the proposed SPMs is evaluated by first comparing the techno-economic and environmental assessment results with those of a diesel power plant. This is also done by comparing the results with some existing related outputs in the literature, which are reported for solar photovoltaic systems in different regions of the world. The research results indicate that it is possible to develop practical, cost-effective and reliable clean energy systems for the specified communities based on solar photovoltaic technology. The SPMs have the capability to compete with conventional electricity options – diesel/petrol generators with which some households are already familiar. Furthermore, even though the diesel plant’s initial capital cost is as low as ~ 10 - 17% of those of the SPMs, its life cycle costs are ~ 2 - 2.3 times the life cycle costs of the proposed SPMs for the six locations. Over the 25-year project life span, the SPMs clearly provide a significant economic benefit. The battery average SoC probability distribution values of >98% above the minimum set point of 30% were also achieved. The reliability indices, i.e. LOEP of < 5%, availability of > 95% achieved in this study for the SPMs, are also comparable with the existing results in the literature. The SPM’s estimated emission rate is ~57 gCO₂/kWh, which is lower than the values of 576 - 695 gCO₂/kWh obtained for diesel systems. The SPM system’s GWP ranges from 3,409 to 7,945 kgCO₂-eq. Also, the system’s EPBTs and EROIs range from 1.11 to 1.6 years and 15.63 to 22.52, respectively, of the specified locations. The proposed SPM model is based on the global engineering standards and best practices and has very considerable practical applications. These can provide a reference point for governments, policymakers, researchers, designers, planners, and other stakeholders of interest in conceptualising and proceeding with the design, planning, and development of new electrification systems for remote communities.</p>

Techno-Economic and Life-Cycle Impact Analysis of Solar Photovoltaic Microgrid Systems for Off-Grid Communities

<p>This thesis proposes Solar Photovoltaic Microgrids (SPMs) for six different remote communities in Nigeria, one from each of the country’s geopolitical zones. The research analysis is presented based on the basic load demand of 24 households within each of the selected communities. The arrangements of the houses are obtained from the community’s layout provided by a building consortium. The study first presents the intended users’ basic energy needs and their daily energy usage. The available solar energy resources of the different locations are also carefully examined, in relation to their disparities, intermittent characteristics and seasonal variations. The research also emphasises the possibility of load growth. With such consideration, more practical electrification solutions can be achieved. The study considers users’ electricity demand growth of 25 to 75% of the baseline value of 175 kWh/d. The photovoltaic microgrid systems are modelled in the DIgSILENT PowerFactory environment. The lengths of the lines running from the electric power plant to the households are obtained from the community’s layout. This information is included in the model, coupled with the solar energy data and the technical configurations of the PV arrays. The effectiveness of the proposed SPMs is evaluated by first comparing the techno-economic and environmental assessment results with those of a diesel power plant. This is also done by comparing the results with some existing related outputs in the literature, which are reported for solar photovoltaic systems in different regions of the world. The research results indicate that it is possible to develop practical, cost-effective and reliable clean energy systems for the specified communities based on solar photovoltaic technology. The SPMs have the capability to compete with conventional electricity options – diesel/petrol generators with which some households are already familiar. Furthermore, even though the diesel plant’s initial capital cost is as low as ~ 10 - 17% of those of the SPMs, its life cycle costs are ~ 2 - 2.3 times the life cycle costs of the proposed SPMs for the six locations. Over the 25-year project life span, the SPMs clearly provide a significant economic benefit. The battery average SoC probability distribution values of >98% above the minimum set point of 30% were also achieved. The reliability indices, i.e. LOEP of < 5%, availability of > 95% achieved in this study for the SPMs, are also comparable with the existing results in the literature. The SPM’s estimated emission rate is ~57 gCO₂/kWh, which is lower than the values of 576 - 695 gCO₂/kWh obtained for diesel systems. The SPM system’s GWP ranges from 3,409 to 7,945 kgCO₂-eq. Also, the system’s EPBTs and EROIs range from 1.11 to 1.6 years and 15.63 to 22.52, respectively, of the specified locations. The proposed SPM model is based on the global engineering standards and best practices and has very considerable practical applications. These can provide a reference point for governments, policymakers, researchers, designers, planners, and other stakeholders of interest in conceptualising and proceeding with the design, planning, and development of new electrification systems for remote communities.</p>

Residential Construction with a Focus on Evaluation of the Life Cycle of Buildings

The article focuses on highlighting the role of life cycle costing (LCC) in the preparatory and implementation phase of residential projects. It involves the evaluation of several investment scenarios in the pre-investment phase, the choice between variants of the design of the entire building or its parts, and the choice of variants of structures and equipment with acceptable parameters. An innovative method of evaluating the life cycle of buildings is described in the article. This method was tested in selected residential projects realized by Skanska in the Czech Republic. Experience from construction practice shows that the choice of variants, constructions, or equipment of buildings only on the basis of the lowest acquisition costs (lowest bid prices) is wrong. The LCC calculation tool has been designed to model life cycle costs of individual variants of construction designs with different input parameters. It is possible to analyze the components or equipment that have the greatest impact on total life cycle costs. The article presents a tool that evaluates the long-term economic efficiency of the proposed residential buildings in terms of analysis of life cycle costs. The article will also expand the knowledge of the professional and general public about the importance of examining investment and operating costs already in the phase of construction preparation.