Energy demand and greenhouse gases emissions in the life cycle of tractors

Mitigating Curtailment and Carbon Emissions through Load Migration between Data Centers

The effectiveness and efficiency of regulatory and other policy approaches intended to reduce the greenhouse gas emissions from transportation fuels can hinge on the fuel life-cycle analysis (LCA). Emerging regulation has raised urgent questions about both definition and evaluation of life-cycle emissions, and the effectiveness, efficiency and equity of regulatory approaches which use such analyses. This paper focuses on the LCA for transportation fuels from unconventional hydrocarbon sources and associated regulatory issues and implications, and examines these in the context of experience gained in the study of conventional hydrocarbon sources, biofuels, electric vehicles, and other alternatives. Critical issues arise in the regulatory use of life-cycle emissions analysis when comparing different types of fuels, for different types of vehicles, including:Uncertainty in life-cycle emissions - Differences in estimates of the life-cycle emissions for one fuel can exceed the differences in estimates for different fuels; boundaries, accounting, aggregation and accuracy of LCA are each critical and determining issues in its application in regulations.Flexible pathways - In order to incentivize innovation in fuel production, many pathways (with the ability to be altered) are needed to map production from each individual agent, who will each have their own process.Energy security - Regulation to lower the life-cycle emissions is often also intended to improve energy security (e.g. by increasing supplies of indigenous biofuels); however, in the case of unconventional sources of oil such regulations may aggravate energy security. For complex policies, such as those involving LCA - especially where there are international ramifications - much broader dialogue is needed to improve the policy's effectiveness, efficiency and ultimately credibility. INTRODUCTION Emerging regulation of life-cycle greenhouse gas emissions for transportation fuels has raised urgent questions about both definition and evaluation of life cycle emissions, and the effectiveness, efficiency and equity of regulatory approaches which use such analyses. The net emissions from a transportation fuel system depend on the definition of system boundaries, which should be appropriate for its use whether that be to provide insight or for a specific regulatory application. For example, inclusion of emissions from the production of vehicles would add to the system--or life-cycle - greenhouse gas emissions of a transportation fuel. For petroleum-based transportation fuels, the use of the fuel results in about five times the greenhouse gas emissions as in its production (EU JRC 2011, NETL 2008). Consistent application of aggregation, accuracy, and transparency of data are also important when making a comparison between any two production pathways. Critical issues arise in the regulatory use of life-cycle emissions when comparing different types of fuels, for different types of vehicles. It is important to note that a life-cycle assessment tool is not needed for regulatory use if there is a comprehensive policy on emissions across all regions and sectors of society - the cost of emissions would be accounted for where they occur. However, in the absence of a comprehensive policy, accurate and consistent life-cycle assessment can have a useful role when accounting for emissions from the life cycle of a fuel.

Beginning with model year 2012, light-duty vehicles sold in the U.S. are subject to new rules that regulate tailpipe greenhouse gas (GHG) emissions based on grams of CO(2)-equivalent per mile (gCO(2)e/mi). However, improvements in vehicle technology, lower-carbon fuels, and improvements in GHG accounting practices which account for distortions related to emissions timing all contribute to shifting a greater portion of life cycle emissions away from the vehicle use phase and toward the vehicle production phase. This article proposes methods for calculating time-corrected life cycle emissions intensity on a gCO(2)e/mi basis and explores whether regulating only tailpipe CO(2) could lead to an undesirable regulatory outcome, where technologies and vehicle architectures with higher life cycle GHGs are favored over technologies with lower life cycle emissions but with higher tailpipe GHG emissions. Two life cycle GHG assessments for future vehicles are presented in addition to time correction factors for production and end-of-life GHG emissions. Results demonstrate that, based on the vehicle designs considered here, there is a potential for favoring vehicles with higher life cycle emissions if only tailpipe emissions are regulated; moreover, the application of time correction factors amplifies the importance of production emissions and the potential for a perverse outcome.

Addressing the social life cycle inventory analysis data gap: Insights from a case study of cobalt mining in the Democratic Republic of the Congo

Life cycle assessment provides a comprehensive framework to evaluate the total greenhouse gas (GHG) emissions from electrified vehicles (EVs) and their potential for GHG reduction as they gain market share. The magnitude of EVs¿ contribution will depend on the specific combinations of fueling strategies and the other vehicle technologies adopted. For instance, the GHG emissions from plug-in electric vehicles (PHEVs) could increase life cycle emissions if the vehicle is driven in a region with a high carbon grid. Also, vehicle lightweighting with lighter, high strength materials decreases use phase emissions but can increase emissions throughout the material production process. This research develops a method to evaluate life cycle emissions from a lightweight PHEV for use in diverse electric fueling regions. A life cycle model is constructed using: 1) Autonomie, a vehicle simulation software, 2) GREET, a vehicle and fuel cycle model, and 3) eGrid, a database with regional information about the US electric power sector. The life cycle analysis demonstrates the importance of considering vehicle production emissions when using energy intensive materials to reduce mass from a vehicle, since life cycle GHGs for the 10% lightweight carbon fiber vehicle are higher than the baseline steel vehicle. However, as a higher percentage of steel is replaced with carbon fiber, total life cycle GHGs decrease. Regional impacts of the electric grid are shown to be significant, with the potential to decrease life cycle emissions by more than four times the reductions possible with the best-case lightweight scenario.

Recent legislative mandates have been enacted at state and federal levels with the purpose of reducing life cycle greenhouse gas (GHG) emissions from transportation fuels. This legislation encourages the substitution of fossil fuels with ‘low‐carbon’ fuels. The burden is put on regulatory agencies to determine the GHG‐intensity of various fuels, and those agencies naturally look to science for guidance. Even though much progress has been made in determining the direct life cycle emissions from the production of biofuels, the science underpinning the estimation of potentially signifi cant emissions from indirect land use change (ILUC) is in its infancy. As legislation requires inclusion of ILUC emissions in the biofuel life cycle, regulators are in a quandary over accurate implementation. In this article, we review these circumstances and offer some suggestions for how to proceed with the science of indirect effects and regulation in the face of uncertain science. Besides investigating indirect deforestation and grassland conversion alone, a more comprehensive assessment of the total GHG emissions implications of substituting biofuels for petroleum needs to be completed before indirect effects can be accurately determined. This review fi nds that indirect emissions from livestock and military security are particularly important, and deserve further research. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd

Author(s): Kendall, Alissa; Ambrose, Hanjiro; Maroney, Erik A. | Abstract: In the United States, vehicle emissions are responsible for 29% of total greenhouse gas (GHG) emissions with the majority of these coming from light-duty vehicles. To reduce GHG emissions, the U.S. has adopted policies to support the development and deployment of low-carbon fuels and zero emission vehicles (ZEVs—e.g., plug-in hybrid electric vehicles [PHEVs] and battery electric vehicles [EVs]).Most current policies focus on emissions from vehicle operation only, omitting significant contributions from vehicle production and other parts of the vehicle and energy life cycle.GHG emissions from vehicle operation and even from operation plus production are almost always lower for EVs than for conventional internal combustion engine vehicles (see Figure). However, as EVs become more efficient, low-carbon electricity becomes more common, and the size of the global EV fleet increases, emissions from production and other non-operation parts of the life cycle become increasingly important.Researchers at UC Davis studied: (i) the effect of different factors on life cycle emissions; (ii) the impact of excluding life cycle emissions from policies; and (iii) potential strategies that might be used to effectively incorporate life cycle emissions in light-duty vehicle GHG policy. This policy brief summarizes the findings from that project.View the NCST Project Webpage

SummaryFuel economy has been an effective indicator of vehicle greenhouse gas (GHG) emissions for conventional gasoline‐powered vehicles due to the strong relationship between fuel economy and vehicle life cycle emissions. However, fuel economy is not as accurate an indicator of vehicle GHG emissions for plug‐in hybrid (PHEVs) and pure battery electric vehicles (EVs). Current vehicle labeling efforts by the U.S. Environmental Protection Agency (EPA) and Department of Transportation have been focused on providing energy and environmental information to consumers based on U.S. national average data. This article explores the effects of variations in regional grids and regional daily vehicle miles traveled (VMT) on the total vehicle life cycle energy and GHG emissions of electrified vehicles and compare these results with information reported on the label and on the EPA's fuel economy Web site. The model results suggest that only 25% of the life cycle emissions from a representative PHEV are reflected on current vehicle labeling. The results show great variation in total vehicle life cycle emissions due to regional grid differences, including an approximately 100 gram per mile life cycle GHG emissions difference between the lowest and highest electric grid regions and up to a 100% difference between the state‐specific emission values within the same electric grid regions. Unexpectedly, for two regional grids the life cycle GHG emissions were higher in electric mode than in gasoline mode. We recommend that labels include stronger language on their deficiencies and provide ranges for GHG emissions from vehicle charging in regional electricity grids to better inform consumers.

Buildings contribute to greenhouse gas (GHG) emissions throughout their life—from material extraction and production to building demolition and disposal. Current GHG emission reduction efforts largely focus on building operation, typically ignoring embodied emissions. One of the main barriers affecting the uptake of embodied GHG emissions considerations is the uncertainty related to the economic value of a building with reduced life-cycle GHG emissions. A conceptual approach is presented for integrating the life-cycle GHG emissions of a building into an economic evaluation. A case study detached residential dwelling located in Melbourne, Australia, is used to demonstrate the approach using a range of economic valuation approaches. One approach, using a carbon tax, shows that the effective cost for a single household would be over A$2000 for the first year, rising to almost A$5000 in 10 years. Across the range of evaluation approaches considered, the total cost to the householder is found to be between A$4600 and A$7860. With the embodied GHG emissions accounting for over 66% of the case study’s life-cycle GHG emissions, the majority of the economic liability for the householder relates to the initial construction and ongoing material replacement of the building. Policy relevance This research provides a comprehensive and integrated approach to GHG emissions and economic assessment of residential buildings. This could be used to drive better decisions in building construction and operation through policy improvement, generating greater understanding of the GHG emissions of buildings and the economic value of GHG emissions. By quantifying the total GHG emissions over a building’s life-cycle and examining ecological and financial implications, new data can provide the basis for policy measures that transform the value of GHG emissions in property. The total life-cycle approach to GHG emissions can be used by developers or builders, for example, to demonstrate the potential financial implications of their choices. However, given its current format, there is a need to improve policy measures such as improved carbon tax strategies and the generation of an annual tax for the economic value implications to be realised.

Life-cycle analysis (LCA) is an important tool used to assess the energy and environmental impacts of biofuels. Here, we review biofuel LCA methodology and its application in transportation fuel regulations in the United States, the European Union, and the United Kingdom. We examine the application of LCA to the production of ethanol from corn, sugarcane, corn stover, switchgrass, and miscanthus. A discussion of methodological choices such as co-product handling techniques in biofuel LCA is also provided. Further, we discuss the estimation of greenhouse gas (GHG) emissions of land use changes (LUC) potentially caused by biofuels, which can significantly influence LCA results. Finally, we provide results from LCAs of ethanol from various sources. Regardless of feedstock, bioethanol offers reduced GHG emissions over fossil-derived gasoline, even when LUC GHG emissions are included. This is mainly caused by displacement of fossil carbon in gasoline with biogenic carbon in ethanol. Of the ethanol pathways examined, corn ethanol has the greatest life-cycle GHG emissions and offers 30% reduction in life-cycle GHG emissions as compared to gasoline when LUC GHG emissions are included. Miscanthus ethanol demonstrates the highest life-cycle GHG emissions reductions compared to gasoline, 109%, when LUC GHG emissions are included.

Forest carbon accounting methods and the consequences of forest bioenergy for national greenhouse gas emissions inventories

BIM-based life cycle environmental performance assessment of single-family houses: Renovation and reconstruction strategies for aging building stock in British Columbia

Policy initiatives have motivated a search for environmentally sustainable alternatives to fossil‐fuel‐based electricity generation. Agricultural residues such as corn cobs may be a suitable feedstock. A life cycle approach was used to estimate the greenhouse gas (GHG) emission impacts associated with the use of pellets produced from corn cobs as the sole fuel for the generation of electricity at a hypothetically retrofitted coal‐fired generating station in Ontario, Canada. Pellets are compared with current coal and hypothetical natural gas combined cycle (NGCC) facilities. A life cycle model and soil carbon model calibrated for the agricultural region of interest were combined to quantify the GHG emissions of the biomass product system. The corn cob product system's life cycle emissions (240 g CO2eq kWh−1) are 40% and 80% lower than those of the NGCC and coal product systems, respectively. If corn cobs are left in the field to decompose, some carbon is sequestered in the soil, thus their removal from the field and combustion at the generation station represents a net GHG emission, accounting for 60% of life cycle emissions. In addition to the GHG impacts of combustion, removing agricultural residues from fields may reduce soil health, increase erosion and affect soil fertility through loss of soil organic carbon and nutrients. Their sustainable use should therefore consider the maintenance of soil fertility over the long‐term. Nevertheless, the use of the feedstock in place of coal may provide substantial GHG emissions mitigation.

The greenhouse gas emissions of power transformers based on life cycle analysis

Life cycle assessment shows that retrofitting coal-fired power plants with fuel cells will substantially reduce greenhouse gas emissions