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Lifecycle Greenhouse Gas Emissions from Different Light-Duty Vehicle and Fuel Pathways: A Synthesis of Recent Research
7/19/2013
Transitioning to a cleaner fleet of advanced vehicles powered by electricity, hydrogen, and advanced biofuels or petroleum products can yield a significant reduction in greenhouse gas emissions and petroleum consumption. A meaningful assessment of the comparative merits of these alternate fuel pathways requires a solid understanding of their technological potential to reduce emissions. Available studies evaluating full lifecycle emissions rely on various assumptions of that potential and yield a wide range of results. This brief summarizes and synthesizes the results of several recent studies and presents the full range of greenhouse gas emission estimates for each type of advanced vehicle and fuel. It also explains the reasons these estimates vary so widely and identifies opportunities for future analyses that use a consistent set of scenarios with transparent assumptions in order to compare the greenhouse gas impacts of fuel and vehicle pathways.
Authors: Nigro, N.; Jiang, S.
Transportation Energy Futures Series: Alternative Fuel Infrastructure Expansion: Costs, Resources, Production Capacity, and Retail Availability for Low-Carbon Scenarios.
4/1/2013
Achieving the Department of Energy target of an 80% reduction in greenhouse gas emissions by 2050 depends on transportation-related strategies combining technology innovation, market adoption, and changes in consumer behavior. This study examines expanding low-carbon transportation fuel infrastructure to achieve deep GHG emissions reductions, with an emphasis on fuel production facilities and retail components serving light-duty vehicles. Three distinct low-carbon fuel supply scenarios are examined: Portfolio: Successful deployment of a range of advanced vehicle and fuel technologies; Combustion: Market dominance by hybridized internal combustion engine vehicles fueled by advanced biofuels and natural gas; Electrification: Market dominance by electric drive vehicles in the LDV sector, including battery electric, plug-in hybrid, and fuel cell vehicles, that are fueled by low-carbon electricity and hydrogen. A range of possible low-carbon fuel demand outcomes are explored in terms of the scale and scope of infrastructure expansion requirements and evaluated based on fuel costs, energy resource utilization, fuel production infrastructure expansion, and retail infrastructure expansion for LDVs. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored transportation-related strategies for abating GHGs and reducing petroleum dependence.
Authors: Melaina, M. W.; Heath, G.; Sandor, D.; Steward, D.; Vimmerstedt, L.; Warner, E.; Webster, K. W.
Transportation Energy Futures Study Points to Deep Cuts in Petroleum and Emissions; Analysis Snapshot
3/1/2013
The U.S. transportation sector has the technical potential to eliminate reliance on oil and reduce its greenhouse gas emissions by more than 80 percent by 2050. This sector is currently responsible for 71 percent of the nation's total petroleum use and 33 percent of our total carbon emissions. The EERE Transportation Energy Futures study examines underexplored opportunities to combine strategies to increase the efficiency of transportation modes, manage the demand for transportation, and shift the fuel mix to more sustainable sources necessary to reach these significant outcomes.
Transportation Energy Futures Series: Vehicle Technology Deployment Pathways: An Examination of Timing and Investment Constraints
3/1/2013
Scenarios of new vehicle technology deployment serve various purposes; some will seek to establish plausibility. This report proposes two reality checks for scenarios: (1) implications of manufacturing constraints on timing of vehicle deployment and (2) investment decisions required to bring new vehicle technologies to market. An estimated timeline of 12 to more than 22 years from initial market introduction to saturation is supported by historical examples and based on the product development process. Researchers also consider the series of investment decisions to develop and build the vehicles and their associated fueling infrastructure. A proposed decision tree analysis structure could be used to systematically examine investors' decisions and the potential outcomes, including consideration of cash flow and return on investment. This method requires data or assumptions about capital cost, variable cost, revenue, timing, and probability of success/failure, and would result in a detailed consideration of the value proposition of large investments and long lead times. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency effort to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.
Authors: Plotkin, S.; Stephens, T.; McManus, W.
Transitions to Alternative Vehicles and Fuels
1/1/2013
For a century, almost all light-duty vehicles (LDVs) have been powered by internal combustion engines (ICEs) operating on petroleum fuels. Energy security concerns over petroleum imports and the effect of greenhouse-gas (GHG) emissions on global climate are driving interest in alternatives. This report assesses the potential for reducing petroleum consumption and GHG emissions by 80% across the U.S. LDV fleet by 2050, relative to 2005. It examines the current capability and estimated future performance and costs for each vehicle type and non-petroleum-based fuel technology as options that could significantly contribute to these goals. By analyzing scenarios that combine various fuel and vehicle pathways, the report also identifies barriers to implementation of these technologies and suggests policies to achieve the desired reductions. Several scenarios are promising, but strong, effective, and sustained but adaptive policies such as research and development (R&D), subsidies, energy taxes, or regulations will be necessary to overcome barriers such as cost and consumer choice.
Clean Cities 2011 Annual Metrics Report
12/1/2012
This annual report details the petroleum savings and vehicle emissions reductions achieved by the U.S. Department of Energy's Clean Cities program in 2011. The report also details other performance metrics, including the number of stakeholders in Clean Cities coalitions, outreach activities by coalitions and national laboratories, and alternative fuel vehicles deployed.
Authors: Johnson, C.
Clean Cities 2010 Annual Metrics Report
10/1/2012
Each year, the U.S. Department of Energy (DOE) asks Clean Cities coordinators to submit an annual report of their activities and accomplishments for the previous calendar year. Data and information are submitted to an online database that is maintained as part of the Alternative Fuels and Advanced Vehicles Data Center (AFDC) at the National Renewable Energy Laboratory (NREL). Coordinators submit a range of data that characterizes the membership, funding, projects, and activities of their coalitions. They also submit data about sales of alternative fuels, deployment of alternative fuel vehicles (AFVs) and hybrid electric vehicles (HEVs), idle reduction initiatives, fuel economy activities, and programs to reduce vehicle miles traveled (VMT). NREL analyzes the data and translates them into gasoline use reduction impacts, which are summarized in this report.
Authors: Johnson, C.
Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration: Second Results Report
7/1/2012
This report presents results of a demonstration of 12 new fuel cell electric buses (FCEB) operating in Oakland, California. The 12 FCEBs operate as a part of the Zero Emission Bay Area (ZEBA) Demonstration, which also includes two new hydrogen fueling stations. This effort is the largest FCEB demonstration in the United States and involves five participating transit agencies. The ZEBA partnersare collaborating with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory (NREL) to evaluate the buses in revenue service. The first results report was published in August 2011, describing operation of these new FCEBs from September 2010 through May 2011. New results in this report provide an update through April 2012.
Authors: Eudy, L.; Chandler, K.
Renewable Fuels and Lubricants (ReFUEL) Laboratory
3/1/2012
This fact sheet describes the Renewable Fuels and Lubricants (ReFUEL) Laboratory at the U.S. Department of Energy National Renewable Energy Laboratory (NREL) is a state-of-the-art research and testing facility for advanced fuels and vehicles. Research and development aims to improve vehicle efficiency and overcome barriers to the increased use of renewable diesel and other nonpetroleum-based fuels, such as biodiesel and synthetic diesel derived from biomass. The ReFUEL Laboratory features a chassis dynamometer for vehicle performance and emissions research, two engine dynamometer test cells for advanced fuels research, and precise emissions analysis equipment. As a complement to these capabilities, detailed studies of fuel properties, with a focus on ignition quality, are performed at NREL's Fuel Chemistry Laboratory.
Life-Cycle Analysis of Shale Gas and Natural Gas
12/1/2011
The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. Using the current state of knowledge of the recovery, processing, and distribution of shale gas and conventional natural gas, we have estimated up-to-date, life-cycle greenhouse gas emissions. In addition, we have developed distribution functions for key parameters in each pathway to examine uncertainty and identify data gaps - such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings - that need to be addressed further. Our base case results show that shale gas life-cycle emissions are 6% lower than those of conventional natural gas. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty regarding whether shale gas emissions are indeed lower than conventional gas emissions. This life-cycle analysis provides insight into the critical stages in the natural gas industry where emissions occur and where opportunities exist to reduce the greenhouse gas footprint of natural gas.
Authors: Clark, C.E.; Han, J.; Burnham, A.; Dunn, J.B.; Wang, M.
Well-to-Wheels Analysis of Fast Pyrolysis Pathways with GREET
11/1/2011
The pyrolysis of biomass can help produce liquid transportation fuels with properties similar to those of petroleum gasoline and diesel fuel. Argonne National Laboratory conducted a life-cycle (i.e., well-to-wheels [WTW]) analysis of various pyrolysis pathways by expanding and employing the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The WTW energy use and greenhouse gas (GHG) emissions from the pyrolysis pathways were compared with those from the baseline petroleum gasoline and diesel pathways. Various pyrolysis pathway scenarios with a wide variety of possible hydrogen sources, liquid fuel yields, and co-product application and treatment methods were considered. At one extreme, when hydrogen is produced from natural gas and when bio-char is used for process energy needs, the pyrolysis-based liquid fuel yield is high (32% of the dry mass of biomass input). The reductions in WTW fossil energy use and GHG emissions relative to those that occur when baseline petroleum fuels are used, however, is modest, at 50% and 51%, respectively, on a per unit of fuel energy basis. At the other extreme, when hydrogen is produced internally via reforming of pyrolysis oil and when bio-char is sequestered in soil applications, the pyrolysis-based liquid fuel yield is low (15% of the dry mass of biomass input), but the reductions in WTW fossil energy use and GHG emissions are large, at 79% and 96%, respectively, relative to those that occur when baseline petroleum fuels are used. The petroleum energy use in all scenarios was restricted to biomass collection and transportation activities, which resulted in a reduction in WTW petroleum energy use of 92-95% relative to that found when baseline petroleum fuels are used. Internal hydrogen production (i.e., via reforming of pyrolysis oil) significantly reduces fossil fuel use and GHG emissions because the hydrogen from fuel gas or pyrolysis oil (renewable sources) displaces that from fossil fuel na
Authors: Han, J.; Elgowainy, A.; Palou-Rivera, I.; Dunn, J.B.; Wang, M.Q.
Clean Cities Annual Metrics Report 2009 (Revised)
8/10/2011
Each year, the U.S. Department of Energy (DOE) asks Clean Cities coordinators to submit an annual report of their activities and accomplishments for the previous calendar year. Data and information are submitted to an online database that is maintained as part of the Alternative Fuels and Advanced Vehicles Data Center (AFDC) at the National Renewable Energy Laboratory (NREL). Coordinators submit a range of data that characterizes the membership, funding, projects, and activities of their coalitions. They also submit data about sales of alternative fuels, deployment of alternative fuel vehicles (AFVs), hybrid electric vehicles (HEVs), idle reduction initiatives, fuel economy activities, and programs to reduce vehicle miles driven. NREL analyzes the data and translates them into gasoline reduction impacts, which are summarized in this report.
Authors: Johnson, C.
Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration: First Results Report
8/1/2011
This report documents the early implementation experience for the Zero Emission Bay Area (ZEBA) Demonstration, the largest fleet of fuel cell electric buses in the United States. The ZEBA Demonstration group includes five participating transit agencies: AC Transit (lead transit agency), Santa Clara Valley Transportation Authority (VTA), Golden Gate Transit (GGT), San Mateo County Transit District(SamTrans), and San Francisco Municipal Railway (Muni). The ZEBA partners are collaborating with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory (NREL) to evaluate the buses in revenue service.
Authors: Chandler, K.; Eudy, L.
Guide for Identifying and Converting High-Potential Petroleum Brownfield Sites to Alternative Fuel Stations
5/1/2011
Former gasoline stations that are now classified as brownfields can be good sites to sell alternative fuels because they are in locations that are convenient to vehicles and they may be seeking a new source of income. However, their success as alternative fueling stations is highly dependent on location-specific criteria, how to prioritize them, and then applies that assessment framework to five of the most popular alternative fuels?electricity, natural gas, hydrogen, ethanol, and biodiesel.
The second part of this report delves into the criteria and tools used to assess an alternative fuel retail site at the local level. It does this through two case studies of converting former gasoline stations in the Seattle-Eugene area into electric charge stations.
The third part of this report addresses steps to be taken after the specific site has been selected. This includes choosing and installing the recharging equipment, steps to take in the permitting process and key players to include.
Authors: Johnson, C.; Hettinger, D.
Clean Alternative Fuel Vehicle and Engine Conversions; Final Rule
4/8/2011
EPA is streamlining the process by which manufacturers of clean alternative fuel conversion systems may demonstrate compliance with vehicle and engine emissions requirements. Specifically, EPA is revising the regulatory criteria for gaining an exemption from the Clean Air Act prohibition against tamperingfor the conversion of vehicles and engines to operate on a clean alternativefuel. This final rule creates additional compliance options beyond certification that protect manufacturers of clean alternative fuel conversion systems against a tampering violation, depending on the age of the vehicle orengine to be converted. The new options alleviate some economic and proceduralimpediments to clean alternative fuel conversions while maintainingenvironmental safeguards to ensure that acceptable emission levels from converted vehicles are sustained.
