Search Results (182)

To achieve the carbon neutrality target, China has proposed “dual control” policies on provincial energy consumption. However, inter-provincial trade drives significant embodied energy flows beyond local demand. How do we identify key energy consumers driving through other provinces? And how does energy, especially from coal, flow to other provinces? Current studies analyzed regional and sectoral energy flow, which are always separated. And seldom was attention paid to coal flow. Intending to identify the critical energy-consuming province in China and investigate how energy and coal flow out from it, this study applied the EE-MRIO model to measure energy and coal embodied in provincial trades. The results suggest the following: (1) The energy embodied in provincial trade was mostly from energy-rich regions to provinces that lacked energy but had developed economies. Shanxi is a critical embodied-energy export province; (2) neighboring provinces and economically developed provinces drive the most embodied energy from Shanxi, and embodied energy mainly flows from the energy sectors and high-energy-intensity sectors; and (3) the provincial and sectoral coal flow in Shanxi presents consistent characteristics of embodied energy flow. We contributed to understanding the energy equity affected by embodied energy flow and propose energy consumption as a relieving measure. Full article

Buildings account for a major share of global energy demand and emissions, prioritizing lighting for efficiency improvements. This study evaluates a daylight-assisted lighting system’s energy and environmental performance through a fully measurement-based approach. Monitored illuminance data were processed within a transparent workflow linking lighting demand to power use, electricity consumption, and life-c ycle greenhouse gas emissions. Energy demand was derived from luminaire efficacy and an illuminated area, while environmental impacts were quantified using an attributional life cycle assessment (LCA) framework consistent with ISO 14040/14044 standards. Use-phase carbon footprints were calculated with regional grid emission factors, and manufacturing, transport, and end-of-life stages were included as background conditions. The results demonstrate that the daylight-aware control strategy achieved an average electricity reduction of 17% (95% CI: 15.7–18.3%) compared to the constant baseline, with the greatest savings occurring in daylight-rich months. When translated into environmental terms, these operational reductions yielded a corresponding ~17% decrease in use-phase CO₂ emissions under a regional grid factor of 0.40 kg CO₂/kWh. Importantly, the system’s embodied impacts were outweighed within an operational payback period of approximately 18–20 months, underscoring both environmental and economic viability. Sensitivity analyses across illuminance thresholds, luminaire efficacy, and grid emission factors confirmed the robustness of these outcomes. Overall, the study provides a reproducible methodology that directly integrates empirical daylight measurements with life-cycle assessment, clarifying the contribution of smart lighting control to sustainable building design. Full article

The residential building sector is a major contributor to global energy consumption and carbon emissions, making retrofit strategies essential for meeting climate targets. While many studies focus on reducing operational energy, few comprehensively evaluate the trade-offs between operational savings and the embodied carbon introduced by retrofit measures. This study addresses this gap by developing an integrated, novel scenario-based assessment framework that combines dynamic energy simulation and life cycle assessment (LCA) to quantify whole life carbon impacts. Applied to representative Irish housing typologies, the framework evaluates thirty retrofit scenarios across three intervention levels: original fabric, shallow retrofit, and deep retrofit incorporating multiple HVAC technologies and envelope upgrades. Results reveal that while deep retrofits deliver up to 80.2% operational carbon reductions, they also carry the highest embodied emissions. In contrast, shallow retrofits with high-efficiency air-source heat pumps offer near-comparable energy savings with significantly lower embodied impacts. Comparative analysis confirms that reducing heating setpoints has a greater effect on energy demand than increasing system efficiency, especially in low-performance buildings. Over a 25-year lifespan, shallow retrofits outperform deep retrofits in overall carbon efficiency, achieving up to 76% total emissions reduction versus 74% for deep scenarios. Also, as buildings approach near-zero energy standards, the embodied carbon share increases, highlighting the importance of LCA in design decision-making. This study provides a scalable, evidence-based methodology for evaluating retrofit options and offers practical guidance to engineers, researchers, and policymakers aiming to maximize carbon savings across residential building stocks. Full article

In low-carbon transition policy management, rationally determining the energy-related carbon emission responsibilities (ERCERs) across multiple regions is a fundamental issue. Reasonable allocation must take into account regional heterogeneities, such as energy endowments, economic development levels, industrial structures, and complex interconnections within the multi-regional energy supply chain. Previous studies mostly analyzed it via the multi-regional input–output (MRIO) model on the energy-consumption side, often neglecting the regional distribution of energy production and inter-regional energy transport on the energy-production side. This limitation risks a mismatch between energy policies and economic policies in practical policy governance. To address this gap, this study develops an energy allocation-induced MRIO (EA-MRIO) method integrating energy allocation analysis and an MRIO model to trace ERCER transmissions holistically across the entire energy supply chain. The framework covers seven stages including energy supply, inter-regional energy transport, direct energy consumption of end-use sectors, inter-regional intermediate products input and output, final products supply, inter-regional final products transport, and final demand, applied to a case study of China’s 31 provinces in 2017. Results show that ERCERs mainly transfer from western and northern regions to eastern and southern coastal areas: ERCERs embodied by energy production in western and northern provinces first flow to northern coastal provinces (main intermediate products producers), then to eastern and southern coastal provinces (main final products producers), with 23% ultimately attributed to exports. These findings call for allocating ERCERs based on different subregions’ roles within the national energy–economic system to facilitate more equitable and effective carbon reduction policymaking. Full article

The construction sector is a major contributor to environmental degradation due to high energy consumption and CO₂ emissions. This study presents a low-tech, sustainable construction system based on the manual fabrication of curved laminated bamboo beams, assembled with screws and steel straps, without adhesives or heavy machinery. The case study is part of a bamboo roof structure built within Jericoacoara National Park, Brazil, using Dendrocalamus asper for its mechanical strength and carbon storage capacity. The construction process of three vertical lower laminated curved beams (Vig.CLIV-1, CLIV-2, and CLIV-3) was systematized into two main phases—preparation and construction. Due to the level of detail involved, only Vig.CLIV-1 is fully presented, broken down into work items, processes, and sub-processes to identify critical points for quality control and time efficiency. Comparative analysis of the three beams complements the findings, highlighting differences in logistics, labor performance, and learning outcomes. The results demonstrate the potential of this handcrafted system to achieve high geometric accuracy in complex site conditions, with low embodied energy and strong replicability. Developed by bamboo specialists from Colombia and Peru with support from local assistants, this experience illustrates the viability of low-impact, appropriate construction solutions for ecologically sensitive contexts and advances the integration of sustainable, replicable practices in architectural design. Full article

Oil consumption brings both energy security risks and environmental responsibilities. While traditional studies assign environmental responsibility primarily to oil producers, our research uncovers a geographical displacement of accountability: substantial oil volumes are embedded in traded goods and ultimately consumed in distant regions. Although China’s “dual control” policy regulates fossil energy use, it fails to account for the complexities of embodied oil flows. This oversight leads to imbalanced interregional responsibility allocation and resource exploitation issues. Adopting the “consumer pays” principle, this study makes methodological advances by innovatively combining multi-regional input–output (MRIO) modeling with geographically and temporally weighted regression (GTWR) analysis. The integrated approach provides spatial–temporal resolution in tracking embodied oil flows and their drivers across China’s provinces. Key findings include (1) strong concentration of oil inflows in developed eastern and central provinces, alongside rapid growth in southwestern regions; (2) evolving temporal patterns where economic growth and distance remain persistent drivers, while green technology and urbanization emerge as growing mitigating factors; (3) spatially, northwestern regions rely heavily on external supplies due to economic growth and urbanization, southeastern areas face rising transport costs, while green technologies in coastal regions have yet to significantly curb inflows due to rebound effects. These insights provide a new analytical framework for energy policy, supporting region-specific solutions to balance development and sustainability from a consumption perspective. Full article

Life cycle assessment (LCA) is a standardized tool (ISO 14040) used to evaluate the environmental impacts of products and processes across their entire life cycle, from raw material extraction to end-of-life disposal or recycling. It has become particularly important in the context of engineering materials, where sustainability considerations are critical. Despite challenges such as data quality limitations, variations in system boundary definitions, and methodological inconsistencies, LCA remains an essential tool for assessing and improving product sustainability. This work presents a foundational overview of LCA principles and describes a systematic, step-by-step procedure for its effective application. Additionally, this article revisits the fundamental concepts of carbon footprint (CF) analysis as a complementary tool for quantifying greenhouse gas emissions associated with products and activities. CF analysis underscores the necessity of adopting low-carbon materials and manufacturing processes to minimize embodied energy and reduce environmental emissions. Low-carbon materials are characterized by attributes such as being lightweight, recyclable, renewable, bio-based, locally sourced, and safe for public health. Their development balances the reduction of raw material and resource consumption during production, with increasing product performance, recyclability, and service life, reflecting a cradle-to-cradle, circular economy approach. The integration of LCA and CF methodologies provides an integral framework for assessing environmental performance and supports decision-making processes aligned with global sustainability targets. Full article

The building sector is a pivotal driver of global resource depletion and environmental deterioration, being responsible for 40% of raw material consumption, 16% of water usage, 25% of timber utilization, and 40% of total energy demand. It also accounts for 30% of worldwide greenhouse gas (GHG) emissions, predominantly CO₂. The operational phase of buildings is the most energy-intensive and emission-heavy stage, accounting for 85–95% of their total life-cycle energy consumption. This energy is primarily expended on heating, cooling, ventilation, and hot water systems, which are largely dependent on fossil fuels. Furthermore, embodied energy, the cumulative energy expended from the extraction of materials through construction, operation, and eventual demolition, plays a substantial role in a building’s overall environmental footprint. To address these pressing challenges, this study discusses sustainable innovations within green architecture and biomimicry. Our topic supports the 2030 vision Sustainable Development Goals (SDGs), both directly and indirectly (SDGs 7, 9, 11, 12, and 13). This study also explores cutting-edge applications, such as algae- and slime mold-inspired decentralized urban planning, which offer innovative pathways toward energy efficiency and sustainability. Considering the integration of renewable energy sources, passive design methodologies, and eco-friendly materials, this research emphasizes the transformative potential of biomimicry and green architecture in fostering a sustainable built environment, mitigating climate change, and cultivating a regenerative coexistence between human habitats and the natural world. Full article

The life-cycle carbon emissions (LCCE) assessment of dairy barns is crucial for identifying low-carbon transition pathways and promoting the sustainable development of the dairy industry. We applied a life cycle assessment approach integrated with building information modeling and EnergyPlus to establish a full life cycle inventory of the material quantities and energy consumption for dairy barns. The LCCE was quantified from the production to end-of-life stages using the carbon equivalent of dairy barns (CEDB) as the functional unit, expressed in kg CO₂e head⁻¹ year⁻¹. A carbon emission assessment model was developed based on the “building–process–energy” framework. The LCCE of the open barn and the lower profile cross-ventilated (LPCV) barn were 152 kg CO₂e head⁻¹ year⁻¹ and 229 kg CO₂e head⁻¹ year⁻¹, respectively. Operational carbon emissions (OCE) accounted for the largest share of LCCE, contributing 57% and 74%, respectively. For embodied carbon emissions (ECE), the production of building materials dominated, representing 91% and 87% of the ECE, respectively. Regarding carbon mitigation strategies, the use of extruded polystyrene boards reduced carbon emissions by 45.67% compared with stone wool boards and by 36% compared with polyurethane boards. Employing a manure pit emptying system reduced carbon emissions by 76% and 74% compared to manure scraping systems. Additionally, the adoption of clean electricity resulted in a 33% reduction in OCE, leading to an overall LCCE reduction of 22% for the open barn and 26% for the LPCV barn. This study introduces the CEDB to evaluate low-carbon design strategies for dairy barns, integrating building layout, ventilation systems, and energy sources in a unified assessment approach, providing valuable insights for the low-carbon transition of agricultural buildings. Full article

Green and cool roofs have significant potential to reduce energy consumption in buildings, but high initial costs and the need for local adaptation limit their adoption. This study aims to compare the life cycle energy assessment (LCEA) and life cycle cost analysis (LCCA) of green, cool, and standard (fibre cement) roofs in three Brazilian cities with different climatic and economic contexts. Computer simulations were carried out on a multifamily residential building model to assess the energy performance of the roofs. The simulation results and literature data were used to estimate the roofs’ energy consumption and cost over the life cycle. Over a 40-year life cycle, green and cool roofs reduced energy consumption by 13% to 22% compared to standard roofs. Cool roofs showed the lowest life cycle costs, while green roofs faced cost-effectiveness challenges due to high initial and maintenance costs. However, in areas with high energy demands and electricity tariffs, the life cycle cost of green roofs may be decreased. The study highlights the crucial role of material selection in embodied energy and emphasises the dominant impact of the operational phase on energy consumption and life cycle costs. These findings underscore the need for customised design strategies and localised assessments to support decision-making. Full article

As the population increases, the growing demand for residential housing escalates construction activities, significantly impacting global warming by contributing 42% of primary energy use and 39% of global greenhouse gas (GHG) emissions. This study addresses a gap in research on lifecycle assessment (LCA) for Indian residential buildings by evaluating the full cradle-to-grave carbon footprint of a typical single-family house in Northern India. A BIM-based LCA framework was applied to a 110 m² single-family dwelling over a 60-year life span. Operational use performance and climate analysis was evaluated via cove tool. The total carbon footprint over a 60-year lifespan was approximately 5884 kg CO₂e, with operational energy use accounting for about 87% and embodied carbon approximately 11%. Additional impacts came from maintenance and replacements. Energy usage was calculated as 71.76 kWh/m²/year and water usage as 232.2 m³/year. Energy consumption was the biggest driver of emissions, but substantial impacts also stemmed from material production. Cement-based components and steel were the largest embodied carbon contributors. Under the business-as-usual (BAU) scenario, the operational emissions reach approximately 668,000 kg CO₂e with HVAC and 482,000 kg CO₂e without HVAC. The findings highlight the necessity of integrating embodied carbon considerations alongside operational energy efficiency in India’s building codes, emphasizing reductions in energy consumption and the adoption of low-carbon materials to mitigate the environmental impact of residential buildings. Future work should focus on the dynamic modeling of electricity decarbonization, improved regional datasets, and scenario-based LCA to better support India’s transition to net-zero emissions by 2070. Full article

Concrete and other cementitious materials are among the most widely used construction materials worldwide. However, their high embodied carbon emissions and energy-intensive manufacturing processes pose significant environmental challenges. This study assesses the carbon emissions, cost implications, and circularity potential of a novel concrete mix, Tex-crete, which incorporates recycled textile and cardboard fibres as sustainable alternatives to conventional reinforcement and cementitious materials in concrete. The study employs a cradle-to-gate life cycle assessment (LCA) approach to compare carbon emissions and costs across different mix designs, using two case studies: a temporary construction site compound and a footpath. Experimental results indicate that Tex-crete, particularly the KFT mix design (including 2.5% textile fibres with treated kraft fibres), achieves comparable compressive and tensile strength to traditional concrete while demonstrating a net reduction in both carbon emissions (3.38%) and production costs (2.56%). A newly introduced circularity index (CI) further evaluated the reuse, repair, and recycling potential of the novel mix, revealing that KFT exhibits the highest circularity score (0.44). Parametric analysis using Monte Carlo simulations highlighted transportation distance and energy consumption during fibre processing as key factors influencing emissions. The findings provide valuable insights for industry stakeholders seeking sustainable concrete solutions aligned with circular economy principles, offering an optimized balance between environmental performance, structural integrity, and cost-effectiveness. Full article

The building sector significantly contributes to global energy consumption and carbon emissions, primarily due to the extensive use of carbon-intensive materials such as concrete and steel. Mass timber construction, particularly using cross-laminated timber (CLT), offers a promising low-carbon alternative. This study aims to calculate the embodied carbon emissions and biogenic carbon storage of a CLT-based affordable housing project, 340+ Dixwell in New Haven, Connecticut. This project was designed using a honeycomb structural system, where mass timber floors and roofs are supported by mass timber-bearing walls. The authors are not aware of a prior study that has evaluated the life cycle impacts of honeycomb mass timber construction while considering Timber Use Intensity (TUI). Unlike traditional post-and-beam systems, the honeycomb design uses nearly twice the amount of timber, resulting in higher carbon sequestration. This makes the study significant from a sustainability perspective. This study follows International Standard Organization (ISO) standards 14044, 21930, and 21931 and reports the results for both lifecycle stages A1–A3 and A1–A5. The analysis covers key building components, including the substructure, superstructure, and enclosure, with timber, concrete, metals, glass, and insulation as the materials assessed. Material quantities were extracted using Autodesk Revit^®, and the life cycle assessment (LCA) was evaluated using One Click LCA (2015)^®. The A1 to A3 stage results of this honeycomb building revealed that, compared to conventional mass timber housing structures such as Adohi Hall and Heartwood, it demonstrates the lowest embodiedf carbon emissions and the highest biogenic carbon storage per square foot. This outcome is largely influenced by its higher Timber Use Intensity (TUI). Similarly, the A1-A5 findings indicate that the embodied carbon emissions of this honeycomb construction are 40% lower than the median value for other multi-family residential buildings, as assessed using the Carbon Leadership Forum (CLF) Embodied Carbon Emissions Benchmark Study of various buildings. Moreover, the biogenic carbon storage per square foot of this building is 60% higher than the average biogenic carbon storage of reference mass timber construction types. Full article

This study addresses the sentiment classification of short texts in teaching evaluations. To mitigate concerns regarding data security in cloud-based sentiment analysis and to overcome the limited feature extraction capacity of traditional deep-learning methods, we propose a distributed symmetric approximate homomorphic hybrid sentiment classification model, denoted BHE+ALBERT-Mixplus. To enable homomorphic encryption of non-polynomial functions within the ALBERT-Mixplus architecture—a mixing-and-enhancement variant of ALBERT—we introduce the BHE (BERT-based Homomorphic Encryption) algorithm. The BHE establishes a distributed symmetric approximation workflow, constructing a cloud–user symmetric encryption framework. Within this framework, simplified computations and mathematical approximations are applied to handle non-polynomial operations (e.g., GELU, Softmax, and LayerNorm) under the CKKS homomorphic-encryption scheme. Consequently, the ALBERT-Mixplus model can securely perform classification on encrypted data without compromising utility. To improve feature extraction and enhance prediction accuracy in sentiment classification, ALBERT-Mixplus incorporates two core components: 1. A meta-information extraction layer, employing a lightweight pre-trained ALBERT model to capture extensive general semantic knowledge and thereby bolster robustness to noise. 2. A hybrid feature-extraction layer, which fuses a bidirectional gated recurrent unit (BiGRU) with a multi-scale convolutional neural network (MCNN) to capture both global contextual dependencies and fine-grained local semantic features across multiple scales. Together, these layers enrich the model’s deep feature representations. Experimental results on the TAD-2023 and SST-2 datasets demonstrate that BHE+ALBERT-Mixplus achieves competitive improvements in key evaluation metrics compared to mainstream models, despite a slight increase in computational overhead. The proposed framework enables secure analysis of diverse student feedback while preserving data privacy. This allows marginalized student groups to benefit equally from AI-driven insights, thereby embodying the principles of educational equity and inclusive education. Moreover, through its innovative distributed encryption workflow, the model enhances computational efficiency while promoting environmental sustainability by reducing energy consumption and optimizing resource allocation. Full article

This review maps the complex relationship between embodied carbon emissions and energy within the construction sector, aiming to generate insights that facilitate more informed and sustainable decision-making for new construction projects. It addresses the challenges associated with the variability in standards, methodologies, and emission factors used in embodied carbon assessments, which contribute to discrepancies and impede the development of cohesive carbon reduction strategies. The paper identifies key drivers of embodied emissions, with a particular emphasis on energy consumption, and represents the findings in the form of a detailed graph, elucidating the interplay between energy use and embodied emissions and providing actionable insights to enhance sustainability selections. Additionally, a case study of four residential low-rise projects in Abu Dhabi is conducted to analyze the energy-based carbon emissions of construction projects, examine their patterns over the entire construction period, and determine the energy-based carbon emission intensity of projects typically powered by diesel generators. This work expands the existing knowledge base by offering actionable insights into how energy-related decisions can significantly influence embodied carbon outcomes and aims to guide stakeholders in optimizing selections to advance sustainability practices within the construction industry. Full article