Carbon Emission Assessment Research Articles

POLICIES AND BUSINESS MODELS FOR THE ELECTRIC MOBILITY REVOLUTION: THE CASE STUDY ON SINGAPORE

A detailed total cost of ownership (TCO) model, with well-to-wheel carbon emissions assessment, is developed to analyze the economic competitiveness of battery electric vehicle (BEV) against conventional internal combustion engine (ICE) vehicles in Singapore. The model fully integrates the unique economic, institutional and social features of Singapore related to the ownership and usage of a passenger vehicle into consideration. Assuming current technologies and no change in the regulatory and policy framework, it is found that BEV is already economically competitive in certain niche markets of Singapore, such as small and midsize vehicles for car-sharing and corporate uses. In the near future, with technological progress, BEVs will become competitive in most parts of the Singapore passenger vehicle market, including small vehicles for household and small and midsize vehicles for car-sharing, corporate and taxi uses. However, certain supportive policies are called for, based on policy simulation results, to effectively accelerate the adoption of BEVs. Evidence also shows that supports should be given to the development of charging infrastructure at an early stage of BEV adoption.

Combining life cycle assessment and Building Information Modelling to account for carbon emission of building demolition waste: A case study

Building demolition waste presents a significant challenge due to its large scale. Especially, the treatment of waste (i.e. demolition, collection, sorting, transportation, recycling and landfill) has environmental implications, e.g. carbon emissions due to energy consumed by equipment and vehicles. Therefore, it is imperative to identify the appropriate waste treatment methods with low carbon emissions. However, previous studies predominately focused on quantifying the carbon emission of buildings. In contrast, the carbon emission derived from the treatment of building demolition waste is largely overlooked. A conceptual framework is developed in this study to facilitate the assessment of carbon emissions over the life cycle of building demolition waste. In this conceptual framework, Building Information Modelling provides an effective approach to harvest data and feed into the Life Cycle Assessment. Case study of a high-rise residential building was conducted to showcase how this framework can be implemented in practice. Results showed that the environmental benefit derived from recycling of building demolition waste varies from one material to another. The recycling of metal waste has far higher environmental benefits compared to masonry wastes. In particular, aluminum could contribute to as high as 45% of carbon emission reduction despite only accounting for 0.66% of the total weight. Across various lifecycle stages, the onsite collection and sorting is the biggest contributor to the total carbon emission. In addition, on-site recycling has better performance compared to factory recycling and landfill in terms of carbon emissions. Furthermore, a large scale inventories are developed as an outcome of this case study. These findings provide useful inputs to the future endeavor of building demolition waste recycling in a bid to reduce the associated carbon emissions.

The life cycle assessment of energy and carbon emissions on wool and nylon carpets in the United States

The U.S. textile industry, which includes the carpet industry, is expected to continue to consume a large amount of energy and generate a large amount of carbon emissions. Since the environmental impacts of the carpet industry are expected to grow in the next decade, it is necessary to estimate the energy consumption and carbon emissions generated at each stage of the entire life cycle of carpet to mitigate these environmental impacts. Thus, this study conducts a life cycle assessment of energy and carbon emissions on two types of carpet -- a wool carpet and a nylon carpet -- from raw material production to recycling and disposal, along with transportation activities. In addition, this study utilizes a system dynamics approach to investigate the impacts of the uncertainty of market share on total energy consumption and total carbon emissions. The results of this study indicate that the production of 0.09 square meter of a carpet tile requires 20.42 MJ of energy and generates 6.35 kg CO2-e of emissions for the wool carpet, and consumes 25.42 MJ of energy and produces 4.80 kg CO2-e of emissions for the nylon carpet. To reduce energy consumption, the use stage of a wool carpet and the raw material production stage of a nylon carpet need to made more efficient, while to reduce carbon emissions, the raw material production stage of a wool carpet and a nylon carpet need to be improved.

Life cycle carbon emissions inventory of brick masonry and light steel framing houses in Brasilia: proposal of design guidelines for low-carbon social housing

Abstract This study evaluated the CO2eq emissions during the life cycle of two social housing projects in the city of Brasilia. A house of ceramic brick masonry was compared to a light steel framing one. The life cycle carbon emissions assessment (LCCO2A) with a cradle-to-grave approach was used. The relation between the thermal performance of the wall systems and CO2eq emissions in the operational phase of the houses were evaluated using the DesignBuilder software. In addition, six scenarios composed of three CO2eq emission factors from the Brazilian electrical grid and two schedules of occupation of houses (full and part time) were evaluated. The brick masonry house presented less CO2eq emissions than the light steel framing one. For both houses, the operational phase was the most significant regarding the total CO2eq emissions (50% to 70%), followed by the construction (20% to 30%), maintenance (11% to 20%) and end-of-life (lower than 1%) phases. The results also showed the importance of considering different CO2eq emission factors for the Brazilian context in the operational phase. Finally, based on the results obtained, design guidelines for low carbon social housing were proposed.

A dynamic life cycle carbon emission assessment on green and non-green buildings in China

As most promoted solution of climate change, green buildings become more popular and widely promoted in China recently. This paper compared the carbon emissions of green buildings with non-green buildings; therefore, a life cycle carbon emission assessment approach (LCA) was attempted. In the present paper, we have integrated existing database Building Environmental Load Evaluation System (BELES) developed by Tsinghua University and twenty-six real existing buildings (nine residential and seventeen commercial buildings). Buildings located in two major climate zones were selected, namely, zone II and III. Five phases were defined for a whole life cycle of building: Phase 1 Raw Materials, Phase 2 Transportation, Phase 3 Construction, Phase 4 Operation & Maintenance and Phase 5 Demolishment. In each phase, the emissions were calculated separately.It is found that whole life cycle CO2 (LCCO2) of green buildings are lower than that of non-green buildings, i.e., 10% for residential and 32% for commercial buildings, respectively. For both residential and commercial buildings, Operational & Maintenance phase contributes the majority of emissions in the whole life cycle, about 69.2–89.3%. Moreover, green buildings have slightly higher embodied CO2 emissions than non-green buildings, but with much lower operational emissions, and this phenomenon is significant in residential buildings. This indicates that the LCCO2 of green buildings start to match with LCCO2 of non-green buildings after operating for certain years, which is the turning point. Furthermore, China implemented Standard for Energy Consumption of Buildings in December 2016, which listed two values for energy efficiency in operational phase, which represents requested and optional. It can be expected that the emissions in Operational & Maintenance phase of green buildings will be further reduced in the future. Consequently, in the future, the dynamic flow of turning point of residential buildings will be shifted downwards from existing 14 years found in this paper.

Quantification of the urban water-energy nexus in México City, México, with an assessment of water-system related carbon emissions

Global urbanisation will put considerable stress on both water and energy resources. While there is much research at the national and regional levels on the energy implications of water supply (the urban water-energy ‘nexus’), there is relatively little at the city scale. This literature is further diminished when attempting to account for the climate impact of urban water systems. A study of the urban water-energy-climate nexus is presented for México City. It is shown that 50% of México City water comes from a local aquifer with a further 30% deriving from energy-intensive surface sources which are pumped over considerable topography. The water supply system consumes 90% of the water system energy demand, and is responsible for the majority (90%) of the CO2e emissions. In the wastewater sector, 80–90% is discharged with no or little treatment, with correspondingly low energy demand. The small fraction that is treated accounts for the majority of energy use in the wastewater sector. This study shows the uncertainty in energy demand and CO2e emissions when reliant on secondary data which considerably over/under-estimate energy use compared with primary data. This has implications when assessing energy and carbon budgets. Three water savings options are assessed for their impact on energy and CO2e emissions reductions. Considerable reductions in water supply volumes and concomitant energy consumption and CO2e emissions are possible. However the extent of implementation, and the effectiveness of any implemented solutions depend on financing, institutional backing and public support. An additional measure to reduce the climate impact is to switch from traditional to renewable fuels. This work adds city-level quantification of the urban water-energy-climate nexus, allowing policy makers to discern which water-system elements are responsible for the greatest energy use and climate impact, and are better equipped to make targeted operational decisions.

Carbon Emission Assessment in the Production Process of Panel Furniture

Carbon Emission Assessment in the Production Process of Panel Furniture

Systematic Assessment of Carbon Emissions from Renewable Energy Access to Improve Rural Livelihoods

One way of increasing access to electricity for impoverished unconnected areas without adding significant amounts of CO2 to the atmosphere is by promoting renewable energy technologies. However, decision-makers rarely, if ever, take into account the level of in-built energy requirements and consequential CO2 emissions found in renewable energy, particularly photovoltaic cells and related equipment, which have been widely disseminated in developing countries. The deployment of solar panels worldwide has mostly relied on silicon crystalline cell modules, despite the fact that less polluting material—in particular, thin film and organic cells—offers comparatively distinct technical, environmental and cost advantages characteristics. A major scientific challenge has thus been the design of a single decision-making approach to assess local and global climate change-related impacts as well as the socio-economic effects of low-carbon technology. The article focuses on the functions of the multi-criteria-based tool SURE-DSS and environmental impact analysis focused on greenhouse gases (GHG) emissions balance to inform the selection of technologies in terms of their impact on livelihoods and CO2eq. emissions. An application in a remote rural community in Cuba is discussed. The results of this study show that while PV silicon (c-Si), thin film (CdTe) and organic solar cells may each equally meet the demands of the community and enhance people’s livelihoods, their effect on the global environment varies.

High-resolution mapping of time since disturbance and forest carbon flux from remote sensing and inventory data to assess harvest, fire, and beetle disturbance legacies in the Pacific Northwest

Abstract. Accurate assessment of forest carbon storage and uptake is central to policymaking aimed at mitigating climate change and understanding the role forests play in the global carbon cycle. Disturbances have highly diverse impacts on forest carbon dynamics, making them a challenge to quantify and report. Time since disturbance is a key intermediate determinant that aids the assessment of disturbance-driven carbon emissions and removals legacies. We propose a new methodology of quantifying time since disturbance and carbon flux across forested landscapes in the Pacific Northwest (PNW) at a fine scale (30 m) by combining remote sensing (RS)-based disturbance year, disturbance type, and above-ground biomass with forest inventory data. When a recent disturbance is detected, time since disturbance can be directly determined by combining three RS-derived disturbance products, or time since the last stand clearing can be inferred from a RS-derived 30 m biomass map and field inventory-derived species-specific biomass accumulation curves. Net ecosystem productivity (NEP) is further mapped based on carbon stock and flux trajectories derived from the Carnegie-Ames-Stanford Approach (CASA) model in our prior work that described how NEP changes with time following harvest, fire, or bark beetle disturbances of varying severity. Uncertainties from biomass map and forest inventory data were propagated by probabilistic sampling to provide a statistical distribution of stand age and NEP for each forest pixel. We mapped mean, standard deviation, and statistical distribution of stand age and NEP at 30 m in the PNW region. Our map indicated a net ecosystem productivity of 5.9 Tg C yr−1 for forestlands circa 2010 in the study area, with net uptake in relatively mature (> 24 years old) forests (13.6 Tg C yr−1) overwhelming net negative NEP from tracts that had recent harvests (−6.4 Tg C yr−1), fires (−0.5 Tg C yr−1), and bark beetle outbreaks (−0.8 Tg C yr−1). The approach will be applied to forestlands in other regions of the conterminous US to advance a more comprehensive monitoring, mapping, and reporting of the carbon consequences of forest change across the US.

Life-cycle carbon emission assessment and permit allocation methods: A multi-region case study of China’s construction sector

China is making efforts to reduce carbon emissions from the building industry, and carrying out an allocation and trading system for building emissions. However, to date, methods for using existing statistical data to assess the emissions of the construction sector and to make decisions affecting permit allocation are still unclear. In this context, a process is proposed in this study to calculate the life-cycle emissions of regional construction sectors in China, and a multi-criteria Gini coefficient is introduced as an indicator for emission permit allocation. Statistical data of the construction sector for 2004–2013 were analyzed. The results indicated an overall trend of increased emissions from China’s construction sector, of which the production phase of buildings was shown to be the largest contributor. Various characteristics for different life-cycle sub-processes were also discussed at the provincial level. Finally, a case study of emissions from the construction sector was conducted on the basis of a multi-criteria Gini coefficient. Relevant analyses revealed the major regions in carbon reduction practices from a comprehensive view of efficiency and equality. In addition, suggestions were provided for allocating emissions for regional construction sectors. Overall, the present study would be helpful in the calculation, assessment, and allocation of emissions from China’s construction sector. It should also provide insight into decision-making about low-carbon development policy of the building industry.

Enhancing sustainable construction in the building sector in Uganda

To further the sustainability agenda of the building sector, recent research and practice suggest that integrating embodied carbon (EC) in the sustainability assessment of buildings is necessary. This paper presents an investigation to assess whether the consideration of EC in the development approval process (DAP) could enhance sustainable construction (SC). A recent proposal for integrating the assessment of EC in the DAP of building projects in Uganda was used. Structured interviews were used to collect data from construction professionals. Findings show that construction professionals were highly aware of SC, suggesting that initiatives of enhancing SC could be easily appreciated. However, the concept of SC was found to be largely interpreted in terms of environmental sustainability, implying that measures that highly promote environmental sustainability could be adopted. A hypothesis test confirmed that integrating the assessment of EC in the DAP of building projects in Uganda could enhance SC. This provided new evidence to corroborate the assertion that assessment of carbon emissions associated with buildings can enhance sustainable construction. Having further found that social sustainability could be enhanced the most, this study provides new evidence linking the assessment of EC to promoting social sustainability. Recommendations on introducing the assessment of EC in the DAP of buildings in Uganda are also provided. These include taking necessary steps to increase awareness of SC, implementation of a pilot program in a selected area of Uganda, and further research to capture more opinions from stakeholders, other than construction professionals. Overall, this study shows that transition to sustainable low carbon development in developing countries is possible and a potential way of achieving this could be through implementing measures that bring carbon emissions to bear on the environmental impact assessment of prospective buildings.

Life cycle carbon emissions assessment using an eco-demonstrator aircraft: the case of an ecological wing design

Airplane production is at record levels, and thus, vast quantities of new aircraft of every class will be produced in the near future. Concerns regarding local and global environmental conditions are being raised in the developed and developing worlds. Consequently, new aircraft with greater dependence on environmentally friendly materials are needed. Life cycle carbon emissions assessment (LCCEA) uses traditional and innovative materials for wing construction to improve the ecological appeal of aeronautical structures. For each part of the wing, there are preferred materials, and in this study, additional improvement scenarios were analyzed. Carbon fiber composites performed better than the industry standards of aluminum and balsa, consistent with industry claims that these composites not only reduce aircraft weight but are also more eco-friendly. These results also indicate that research on structural applications of innovative biosourced materials could provide long-term advantages for mitigating global warming even if substantial technological challenges remain.

Assessment of Current Energy Consumption Practices, Carbon Emissions and Indoor Air Pollution in Samagaun, Manaslu Conservation Area, Nepal

Nepal is one of the lowest energy consuming countries in the world. More than 85 percent of its total energy comes from traditional biomass energy such as forests, agricultural residues and by-products from crops. Due to increasing per capita energy consumption, natural resources are being depleted with heavy emissions of GHGs in the atmosphere, which causes global warming. The main objective of the study was to investigate current energy consumption practices, to estimate particulate matter and carbon emissions from current practices and to recommend the most suitable alternative energy technologies. The fieldwork was based on primary and secondary data with a design methodology. Firewood burning was found to be the major source of energy used for cooking purposes in Samagaun. The use of this traditional fuel has negative environmental implications, such as deforestation, indoor air pollution and it ultimately affects human health. The results show that traditional cooking stoves (TCS) are used more than improved cooking stoves (ICS). The total amount of firewood used per day by TCS is 2135 kg/day, and by ICS it is 349 kg/day. The average amount of firewood consumed by traditional and improved cooking stoves per day is 62.79 kg and 43.63 kg, respectively. The annual per capita firewood consumption of TCS and ICS is 4401.9 kg and 3266.7 kg, respectively. The calculation shows that per capita firewood consumption by TCS users is 1.3 times higher than that of ICS users. The annual per capita carbon emissions from TCS and ICS is 8055.47 kg CO2e and 5978.15 kg CO2e, respectively. This calculation shows that ICS emits 1.3 times less CO2 into the atmosphere than the TCS. The average mean particulate concentration at normal atmospheric conditions for a traditional cooking stove was found to be 2866 μg/Nm3 and for an improved cooking stove 1333 μg/Nm3, both of which far exceed the national standard of 230 μg/m3 TSP. Based on the study results, metallic improved cooking stoves could be recommended as the best alternative energy technology in the study area.

Energy Efficient Tunnel Solutions

In terms of both construction and operation, tunnels are the most energy demanding of road infrastructure assets. The construction of a road tunnel is energy intensive due to the volume of excavation required and the energy embodied in the materials that form the structure of the tunnel. In operating a tunnel, energy is consumed to provide adequate lighting, signing and ventilation for drivers, to maintain drainage systems and to deal with emergency situations. The European Directive on the Safe Operation of Road Tunnels requires the installation of engineering and safety systems to maintain the safe operation of the tunnel. As the operational lifetime of a tunnel is typically in excess of 100 years, energy usage through operation can soon outweigh that due to construction and therefore, the former provides the focus for this project. The Realistic Energy Efficient Tunnel Solutions (REETS) project aims to enhance the energy efficiency of road tunnel operation through the promotion and implementation of appropriate technologies.REETS commenced with a wide-ranging review of energy-efficient technologies. This covered technologies developed for tunnels, which could bring benefit through wider adoption, and those used for other applications that have proved effective, and could be used in tunnels. Technologies were considered for each of the main services that together maintain the functionality of a tunnel including: lighting, ventilation, drainage, and temperature regulation, with emphasis placed on the more energy demanding services. The review also covered technologies that can reduce energy consumption, by addressing energy provision and storage, and vehicle-oriented technologies that can improve safety and traffic flow. The various technologies might be implemented during the construction of the tunnel or be retrofitted later in the life cycle. The minimum criteria for technology were to (i) maintain or enhance the current levels of safety and comfort experienced by drivers using tunnels on national road networks, and (ii) meet or challenge existing standards for constructing and operating road tunnels.In the next stage of the REETS project, the most promising technologies will be evaluated through a quantitative assessment of carbon emissions and cost of implementation. The final stage will focus on facilitating the adoption of the most promising technologies through ‘hypothetical deployment’ case studies to identify barriers to the adoption of technologies and appropriate reconciliatory measures.

Integrating clean development mechanism into the development approval process of buildings: A case of urban housing in Uganda

Since climate change is no respecter of geographical boundaries, concerted mitigating actions such as clean development mechanism (CDM), are desirable. In CDM, developed countries can earn certified emission reduction credits from emission reduction projects undertaken in developing countries. Recent research suggests that, theoretically, CDM can be extended to the building sector. However, there is limited research on how CDM can be integrated in the development approval process (DAP) of buildings. This paper presents an investigation on how CDM could be integrated into the DAP of buildings in urban Uganda. A method of process modelling was used to describe the existing DAP, and also to design a new DAP. To demonstrate how CDM could be integrated into the new DAP, a typical dwelling unit was used. Two options for the dwelling were considered: a baseline (i.e. constructed using typical materials, plant, and workforce) and alternative (i.e. constructed using provisions to reduce carbon emissions). The difference in emissions in the two options constituted the basis for a CDM. Results suggested that the existing DAP does not consider carbon accounting and thus was not congruent with CDM modalities. A new DAP which is compatible with CDM was proposed. When the CDM concept was integrated into the new DAP, a bottom-up projection regarding construction of 28,000 houses annually within the capital city showed that reductions of over 200 ktCO2 could be achieved in a period of 10 years. These figures were comparable with prevailing CDM initiatives. The structure of a CDM programme aided by the new DAP was presented and discussed. This study shows that integrating CDM into the DAP of buildings in Uganda is possible if assessment of carbon emissions is incorporated in the existing DAP. The overall findings suggest that CDM could promote market-based mechanisms of enhancing sustainable construction in developing countries.

Life Cycle Building Carbon Emissions Assessment and Driving Factors Decomposition Analysis Based on LMDI—A Case Study of Wuhan City in China

Carbon emissions calculation at the sub-provincial level has issues in limited data and non-unified measurements. This paper calculated the life cycle energy consumption and carbon emissions of the building industry in Wuhan, China. The findings showed that the proportion of carbon emissions in the construction operation phase was the largest, followed by the carbon emissions of the indirect energy consumption and the construction material preparation phase. With the purpose of analyzing the contributors of the construction carbon emissions, this paper conducted decomposition analysis using Logarithmic Mean Divisia Index (LMDI). The results indicated that the increasing buidling area was the major driver of energy consumption and carbon emissions increase, followed by the behavior factor. Population growth and urbanization, to some extent, increased the carbon emissions as well. On the contrary, energy efficiency was the main inhibitory factor for reducing the carbon emissions. Policy implications in terms of low-carbon construction development were highlighted.

Emission and economic performance assessment of a solid oxide fuel cell micro-combined heat and power system in a domestic building

Combined heat and power (CHP) is a promising technological configuration for reducing energy consumption and increasing energy security in the domestic built environment. Fuel cells, on account of their: high electrical efficiency, low emissions and useful heat output have been identified as a key technological option for improving both building energy efficiency and reducing emissions in domestic CHP applications. The work presented in this paper builds upon results currently reported in the literature of fuel cells operating in domestic building applications, with an emission and economic performance assessment of a real, commercially available SOFC mCHP system operating in a real building; under a UK context.This paper aims to assess the emission and economic performance of a commercially available solid oxide fuel cell (SOFC) mCHP system, operating at The University of Nottingham's Creative Energy Homes. The performance assessment evaluates, over a one year period, the associated carbon (emission assessment) and operational costs (economic assessment) of the SOFC mCHP case compared to a ‘base case’ of grid electricity and a highly efficient gas boiler.Results from the annual assessment show that the SOFC mCHP system can generate annual emission reductions of up to 56% and cost reductions of 177% compared to the base case scenario. However support mechanisms such as; electrical export, feed in tariff and export tariff, are required in order to achieve this, the results are significantly less without. A net present value (NPV) analysis shows that the base case is still more profitable over a 15 year period, even though the SOFC mCHP system generates annual revenue; this is on account of the SOFC's high capital cost. In summary, grid interaction and incubator support is essential for significant annual emission and cost reductions compared to a grid electricity and gas boiler scenario. Currently capital cost is the greatest barrier to the economic viability of the system.

Carbon Emission Assessment for Typical Household Appliances Orienting the Green Supply Chain Management for Enterprises

This paper explores on the green supply chain management for enterprises based on the carbon emission assessment for products. The assessment showed that the priorities of green supply chain management measures were different for washing machine, air conditioner and microwave. The washing machine manufacturer should firstly focus on the measures to the upstream suppliers associated with the product eco-design, and secondly the product energy efficiency increase. The air conditioner manufacturer should first focus on the product energy efficiency increase, and secondly the eco-design, especially the refrigerant improvement. But the energy efficiency increase would be the only effective way for microwave. This work shows the method applies to the household appliance manufacturer to identify the green supply chain hot point, as the information of products is easier to obtain, and the effort performance could be shown intuitively along with the consuming process.

Energy Consumption, Carbon Emission and Financial Risk Assessment of Iron and Steel Enterprises in China

This paper combines energy consumption, carbon emission and financial risk assessment of iron and steel enterprises in China for studying. The financial risk of iron and steel enterprises is classified into five main risks: 1) profit risk, 2) insolvency risk, 3) operational risk, 4) development risk and 5) the risk of carbon emission. The 32 iron and steel listed companies of China are examined to test the applicability of the risk assessment system. The results show that the system can better reveal the situation of financial risk and guard against the financial risk of iron and steel enterprises.

Analysis of Industrial Carbon Emissions Assessment and Spatial Distribution

Under the background of ecological civilization, the energy saving and emission reduction, low carbon eco-city construction is booming. At present, China industrial carbon emissions account for more than half of total carbon emissions in the whole society. The analysis of industrial carbon emissions and its spatial distribution is quite important. Consider the Park of Shenzhen international low-carbon city as the research object; based on the enterprise data from the 2011 industrial census, it combines both the top-down and bottom-up methods to evaluate its current industrial carbon emission levels and then discusses the relationship between the industrial structure and carbon emissions. Comprehensive utilization of the spatial distribution function of GIS, the spatial distribution characteristics of industrial carbon emissions and carbon intensity is evaluated, so as to provide the references for the related policy-making of low-carbon ecological city.