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Due to an extensive usage of heavy machinery, the construction sector is criticized as one of the major CO2 emitters. To address climate concerns, mitigating these greenhouse gas (GHG) emissions is important. This study aimed to strategize for "zero emission construction" by assessing the life cycle environmental impacts of diesel, electric, and hybrid construction machinery. By applying life cycle assessment (LCA) principles with adherence to ISO 14040/44 methodologies, this study scrutinizes the environmental repercussions of a standard excavator over 9200 effective operational hours, from raw material acquisition to end-of-life disposal. The results demonstrate a significant reduction in global warming potential (GWP), ozone depletion potential (ODP), and acidification potential (AP) in transitioning from diesel to hybrid and fully electric machines. A nominal increase due to this shift also occurred and impacted categories such as human carcinogenic toxicity (HT), freshwater eutrophication (EP), and marine ecotoxicity (ME); however, a more significant upsurge was noted in terrestrial ecotoxicity (TE) due to battery production. Thus, this study highlights the need for a careful management of environmental trade-offs in the shift toward electrified machinery and the importance of centering on the environmental profile of the battery. Future work should focus on enhancing the environmental profile of battery production and disposal, with policy decisions encouraging holistic sustainability based on green energies in construction projects. [ABSTRACT FROM AUTHOR]

The aim of this paper is to assess university dormitories in terms of life cycle environmental impact and cost, as part of the university campuses sustainable development in southeast China. This life cycle assessment follows the ISO 14040/44 methodology, considering the construction, operation, maintenance and demolition stages. The reference unit of this study is defined as ‘one useful square meter university dormitories with 50 years life time’. This study estimates the life cycle inventory by: 1) tenders information of university dormitories built in the university town of Fuzhou during 2007–2011, 2) water and energy bills of those building over past 5 years, 3) damage and maintenance report of dormitories in Fuzhou University and Fujian University of traditional Chinese medicine during 2004–2014. The Ecoinvent database provides the background data to the analysis. The results indicate that 1) the use stage, including operation and maintenance is the dominate part of the life cycle environmental impacts and cost of university dormitories. 2) The consumption of electricity constitutes the main elements causing the environmental impacts over the life cycle of university dormitories. The technology for more energy efficient building is more important than other factors. 3) The window, concrete, steel, and cement have the largest contribution to the embodied environmental impacts but with the relative small contribution to the life cycle cost. Therefore, two main improving opportunities for reducing the environmental impacts of Chinese university dormitories development are identified: 1) improving building with deep renovation for current dormitories and implementing low energy buildings standards for new built dormitories the buildings energy efficiency and 2) increasing the use of low environmental impacts building material by implementing the carbon tax on main building material and introducing timbers as structure material. Moreover, policies to promote the more renewable energy supply and the implementation of carbon capture and storage technology constitute another import issue. [ABSTRACT FROM AUTHOR]

This paper explores the environmental impacts of drill and blast tunnelling by life cycle assessment. In order to understand the potential of cleaner tunnelling, this paper also analysis the influence of tunnel length and size on pollutant emissions. The excavation practices of rock tunnel in Norway over past 20 years are used to estimate material, equipment and energy consumption. The background data are drawn out from various databases in the Simapro software. The results indicate that: 1) the most important contributor to the climate change and terrestrial eco-toxicity impacts are the loading and hauling process. Its relative contribution also increases when the tunnel becomes bigger or longer. 2) The drilling and blasting process is the dominate contributor to the human toxicity, photochemical oxidant formation, particulate matter formation and terrestrial acidification impacts. The relative influence of this process, however, slightly decreases when tunnels become bigger or longer. 3) The three main sources for all impacts are explosives, diesel and electricity. Therefore, a significant potential of environmental impacts reduction could be reached by optimising drilling and blasting operation to reduce explosive consumption, and by improving renewable energy sharing. [ABSTRACT FROM AUTHOR]

Silver bismuth sulfide nanocrystals (AgBiS2 NCs) embody a pioneering heavy‐metal‐free photovoltaic material renowned for its ultrahigh absorption coefficient, offering promising opportunities for advancing the field of ultra‐thin and biocompatible solar cells. Currently, the fabrication of AgBiS2 NC photovoltaic devices relies on hot‐injection synthesis and subsequent tedious ligand exchange, leading to high production cost, complex processes and environmental pollution. Here, we developed a direct‐synthesis (DS) method without ligand‐exchange for AgBiS2 NC semiconductive inks, significantly simplifying the material preparation and device fabrication processes. The synthesis cost of AgBiS2 inks (17.0 $ g−1) is over an order of magnitude lower than the traditional method (203.5–275.2 $ g−1). Through optimizing synthesis and device structure, a champion power conversion efficiency of 9.32 % was achieved, aligning with the highest reported efficiency (9.17 %) based on ligand‐exchanged methods. In addition, our DS‐AgBiS2 inks show excellent storage stability for over ten months. More importantly, the life cycle assessment (LCA) indicates drastically reduced energy consumption as well as environmental and human health impact for our strategy. The low‐cost and scalable synthesis approach for AgBiS2 NC semiconductive inks present a “greener” pathway for the commercial applications of NC optoelectronics. [ABSTRACT FROM AUTHOR]

Renovating existing buildings is important for achieving global climate targets, necessitating a comprehensive approach to environmental assessment. Life cycle assessment (LCA) is a vital instrument for comprehensively scrutinizing the environmental impacts of buildings over their lifespan. Despite established standards, the intricate nature of renovations introduces complexities in the application of LCA. Moreover, this research argues that recent policy developments in efficient resource use, circular economy, and energy efficiency have incentivized renovations over building new buildings. This study seeks to scrutinize trends and the utilization of LCA in building renovation research, subsequently offering recommendations for future research endeavors and policymaking. Employing a scoping review methodology, the study maps building renovation research utilizing LCA to evaluate environmental impacts, drawing insights from an analysis of 54 scientific articles published between 2005–2022. The findings demonstrate that when renovating an existing building, the options are limited by the prerequisites from the design decisions decades ago. Thus, setting environmental benchmarks reflected in the variability of scope and functional units used in research is challenging. Recommendations for future research emphasize addressing granularity issues in assessments, improving communication of environmental impacts, considering the assessment scale, and incorporating economic and social impacts. These insights aim to guide and enhance building renovations for a more sustainable future. [Display omitted] • The existing research gaps and future recommendations in building renovation-LCAs. • Significant variations in functional units due to existing building constraints. • Ambiguities in the accounting of module D and the system boundaries. • Limited inclusion of economic and social viability in renovation-LCAs. • Research should investigate more impact categories to avoid sub-optimization. [ABSTRACT FROM AUTHOR]