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Future Automotive Systems Technology Simulator (FASTSim) Validation Report
7/27/2018
The National Renewable Energy Laboratory's Future Automotive Systems Technology Simulator (FASTSim) captures the most important factors influencing vehicle power demands and performs large-scale fuel efficiency calculations very quickly. These features make FASTSim well suited to evaluate a representative distribution of real-world fuel efficiency over a large quantity of in-use driving profiles, which have become increasingly available in recent years owing to incorporation of global positioning system data collection into various travel surveys and studies. In addition, by being open source, computationally lightweight, freely available, and free from expensive third-party software requirements, analyses conducted using FASTSim may be easily replicated and critiqued in an open forum. This is highly desirable for situations in which technical experts seek to reach consensus over questions about what vehicle development plans or public interest strategies could maximize fuel savings and minimize adverse environmental impacts with an evolving vehicle fleet. While FASTSim continues to be refined and improved on an on-going basis, this report compiles available runs using versions of the tool from the past few years to provide illustrative comparison of the model results against measured data.
Authors: Gonder, J.; Brooker, A.; Wood, E.; Moniot, M.
Electric School Bus Pilot Project Evaluation
4/20/2018
This report provides an overview of a Massachusetts Department of Energy Resources pilot project to test electric school buses in school transportation operations. Through this project, three electric school buses were deployed at three school districts around the state and bus operations and reliability tracked for approximately one year. The project was designed to understand the opportunities and challenges associated with using electric school buses as a strategy to provide safe, reliable, cost effective school transportation. Key findings and recommendations are also provided.
California Plug-In Electric Vehicle Infrastructure Projections: 2017-2025 - Future Infrastructure Needs for Reaching the State's Zero Emission-Vehicle Deployment Goals
3/27/2018
This report analyzes plug-in electric vehicle (PEV) infrastructure needs in California from 2017 to 2025 in a scenario where the State's zero-emission vehicle (ZEV) deployment goals are achieved by household vehicles. The statewide infrastructure needs are evaluated by using the Electric Vehicle Infrastructure Projection tool, which incorporates representative statewide travel data from the 2012 California Household Travel Survey. The infrastructure solution presented in this assessment addresses two primary objectives: (1) enabling travel for battery electric vehicles and (2) maximizing the electric vehicle-miles traveled for plug-in hybrid electric vehicles. The analysis is performed at the county-level for each year between 2017 and 2025 while considering potential technology improvements. The results from this study present an infrastructure solution that can facilitate market growth for PEVs to reach the State's ZEV goals by 2025. The overall results show a need for 99k-130k destination chargers, including workplaces and public locations, and 9k-25k fast chargers. The results also show a need for dedicated or shared residential charging solutions at multi-family dwellings, which are expected to host about 120k PEVs by 2025. An improvement to the scientific literature, this analysis presents the significance of infrastructure reliability and accessibility on the quantification of charger demand.
Authors: Bedir, A.; Crisostomo, N.; Allen, J.; Wood, E.; Rames, C.
Charging Electric Vehicles in Smart Cities: An EVI-Pro Analysis of Columbus, Ohio
2/7/2018
With the support of the U.S. Department of Energy's Vehicle Technologies Office, the National Renewable Energy Laboratory (NREL) worked with the City of Columbus, Ohio, to develop a plan for the expansion of the region's network of charging stations to support increased adoption of plug-in electric vehicles (PEVs) in the local market. NREL's Electric Vehicle Infrastructure Projection (EVI-Pro) model was used to generate scenarios of regional charging infrastructure to support consumer PEV adoption. Results indicate that approximately 400 Level 2 plugs at multi-unit dwellings and 350 Level 2 plugs at non-residential locations are required to support Columbus' primary PEV goal of 5,300 PEVs on the road by the end of 2019. This analysis finds that while consumer demand for fast charging is expected to remain low (due to modest anticipated adoption of short-range battery electric vehicles), a minimum level of fast charging coverage across the city is required to ease consumer range anxiety concerns by providing a safety net for unexpected charging events. Sensitivity analyses around some key assumptions have also been performed; of these, consumer preference for PHEV versus BEV and for their electric driving range, ambient conditions, and availability of residential charging at multi-unit dwellings were identified as key determinants of the non-residential PEV charging infrastructure required to support PEV adoption. The results discussed in this report can be leveraged by similar U.S. cities as part of a strategy to accelerate PEV adoption in the light-duty vehicle market.
Authors: Wood, E.; Rames, C.; Muratori, M.; Raghavan, S.; Young, S.
Correlations of Platooning Track Test and Wind Tunnel Data
2/5/2018
In this report, the National Renewable Energy Laboratory analyzed results from multiple, independent truck platooning projects to compare and contrast track test results with wind tunnel test results conducted by Lawrence Livermore National Laboratory (LLNL). Some highlights from the report include compiled data, and results from four independent SAE J1321 full-size track test campaigns that were compared to LLNL wind tunnel testing results. All platooning scenarios tested demonstrated significant fuel savings with good correlation relative to following distances, but there are still unanswered questions and clear opportunities for system optimization. NOx emissions showed improvements from NREL tests in 2014 to Auburn tests in 2015 with respect to J1321 platooning track testing of Peloton system. NREL evaluated data from Volpe's Naturalistic Study of Truck Following Behavior, which showed minimal impact of naturalistic background platooning. We found significant correlation between multiple track studies, wind tunnel tests, and computational fluid dynamics, but also showed that there is more to learn regarding close formation and longer-distance effects. We also identified potential areas for further research and development, including development of advanced aerodynamic designs optimized for platooning, measurement of platoon system performance in traffic conditions, impact of vehicle lateral offsets on platooning performance, and characterization of the national potential for platooning based on fleet operational characteristics.
Authors: Lammert, M.; Kelly, K.; Yanowitz, J.
Impacts of Electrification of Light-Duty Vehicles in the United States, 2010-2017
1/25/2018
Plug-in electric vehicles (PEVs) are among the fastest growing drivetrains in the United States and worldwide. Understanding the aggregate impact of PEVs is important when exploring electricity use and petroleum consumption. This report examines the sales of PEVs in the United States from 2010 to 2017, exploring vehicle sales, electricity consumption, petroleum reduction, and battery production.
Authors: Gohlke, D.; Zhou, Y.
Life Cycle Energy and Greenhouse Gas (GHG) Emission Effects of Biodiesel in the United States with Induced Land Use Change Impacts
1/10/2018
Researchers conducted updated simulations to depict a life cycle analysis (LCA) of biodiesel production from soybeans and other feedstocks in the United States. The study addressed in detail the interaction between LCA and induced land use change (ILUC) for biodiesel. Relative to conventional petroleum diesel, soy biodiesel could achieve 76% reduction in GHG emissions without considering ILUC, or 66%-72% reduction in overall GHG emissions when various ILUC cases were considered. Soy biodiesel's fossil fuel consumption rate was also 80% lower than its petroleum counterpart. Furthermore, this study examined the cause and the implication of each key parameter affecting biodiesel LCA results using a sensitivity analysis, which identified the hot spots for fossil fuel consumption and GHG emissions of biodiesel so that future efforts can be made accordingly. Finally, researchers also investigated biodiesel produced from other feedstocks (canola oil and tallow) to contrast with soy biodiesel and petroleum diesel.
Authors: Chen, R.; Qin, Z.; Han, J.; Wang, M.; Taheripour, F.; Tyner, W.; O'Connor, D.; Duffield, J.
Notes: This Bioresource Technology article (Vol. 251 (2018): pp. 249-258) is copyrighted by Elsevier B.V. and only available by accessing it through Science Direct.
Biodiesel Basics
9/29/2017
This fact sheet (updated for 2017) provides a brief introduction to biodiesel, including a discussion of biodiesel blends, which blends are best for which vehicles, where to buy biodiesel, how biodiesel compares to diesel fuel in terms of performance, the difference between biodiesel and renewable diesel, how biodiesel performs in cold weather, whether biodiesel use will plug vehicle filters, how long-term biodiesel use may affect engines, biodiesel fuel standards, and whether biodiesel burns cleaner than diesel fuel. The fact sheet also dismisses the use of vegetable oil as a motor fuel.
Designing a Successful Transportation Project: Lessons Learned from the Clean Cities American Recovery and Reinvestment Act Projects
9/27/2017
The largest source of funding for alternative fuel vehicle and infrastructure projects in the U.S. Department of Energy's Clean Cities program's history came from the American Recovery and Reinvestment Act (Recovery Act). In 2009, the 25 cost-share projects totaled nearly $300 million in federal government investment. This effort included the involvement of 50 Clean Cities coalitions and their nearly 700 stakeholder partners who provided an additional $500 million in matching funds to support projects in their local communities. In total, those 25 projects established 1,380 alternative fueling stations and put more than 9,000 alternative fuel and advanced technology vehicles on the road. Together, these projects displaced 154 million gasoline gallon equivalents (GGE) of petroleum and averted 254,000 tons of greenhouse gas (GHG) emissions, while supporting U.S. energy independence and contributing to regional economic development. During post-project interviews, project leaders consistently cited a number of key components - ranging from technical and logistical factors, to administrative capabilities - for accomplishing an effective and impactful project. This report summarizes the high-level project design and administrative considerations for conducting a successful transportation project.
Authors: Kelly, K.; Singer, M.
Fuel Consumption Sensitivity of Conventional and Hybrid Electric Light-Duty Gasoline Vehicles to Driving Style
8/11/2017
Aggressive driving is an important topic for many reasons, one of which is higher energy used per unit distance traveled, potentially accompanied by an elevated production of greenhouse gases and other pollutants. Examining a large data set of self-reported fuel economy (FE) values revealed that the dispersion of FE values is quite large and is larger for hybrid electric vehicles (HEVs) than for conventional gasoline vehicles. This occurred despite the fact that the city and highway FE ratings for HEVs are generally much closer in value than for conventional gasoline vehicles. A study was undertaken to better understand this and better quantify the effects of aggressive driving, including reviewing past aggressive driving studies, developing and exercising a new vehicle energy model, and conducting a related experimental investigation. The vehicle energy model focused on the limitations of regenerative braking in combination with varying levels of driving-style aggressiveness to show that this could account for greater FE variation in an HEV compared to a similar conventional vehicle. A closely matched pair of gasoline-fueled sedans, one an HEV and the other having a conventional powertrain, was chosen for both modeling and chassis dynamometer experimental comparisons. Results indicate that the regenerative braking limitations could be a main contributor to the greater HEV FE variation under the range of drive cycles considered. The complete body of results gives insight into the range of fuel use penalties that results from aggressive driving and why the variation can be larger on a percent basis for an HEV compared to a similar conventional vehicle, while the absolute fuel use penalty for aggressive driving is generally larger for conventional vehicles than HEVs.
Authors: Thomas, J.; Huff, S.; West, B.; and Chambon, P.
GHG and Criteria Pollutant Emissions Analysis, Final Report
8/2/2017
Direct use of propane in buildings, transportation, and agriculture applications is a proven, cost-effective, and reliable approach to reducing greenhouse gas (GHG) and other emissions. Propane production and delivery is more efficient than electricity provided by the power grid, which is still dominated by fossil fuel power generation and includes large energy losses at the power plant and transmission lines. In the future, the direct use of propane will remain a sustainable strategy for reducing GHG and criteria pollutant emissions. This study presents a comparative analysis of full-fuel-cycle GHG and criteria pollutant emissions for targeted applications in key propane markets, including buildings, agriculture, and transportation.
Authors: Leslie, N.; Rowley, P.
Cow Power: A Case Study of Renewable Compressed Natural Gas as a Transportation Fuel
8/1/2017
This case study explores the production and use of R-CNG--derived from dairy farm manure--to fuel heavy-duty milk tanker trucks operating in Indiana, Michigan, Tennessee, and Kentucky. It describes the joint endeavor of Fair Oaks Farms, an Indiana-based large dairy cooperative, and ampCNG, a provider of natural gas refueling infrastructure.
Authors: Tomich, M.; Mintz, M.
2016 Vehicle Technologies Market Report
6/23/2017
The 2016 Vehicle Technologies Market Report is the eighth edition of this report, which details the major trends in U.S. light-duty vehicle and medium/heavy truck markets as well as the underlying trends that caused them. This report is supported by the U.S. Department of Energy's (DOE) Vehicle Technologies Office (VTO), and, in accord with its mission, pays special attention to the progress of high-efficiency and alternative-fuel technologies.
Authors: Davis, S.C.; Williams, S.E.; Boundy, R.G.; Moore, S.
Challenges and Opportunities of Grid Modernization and Electric Transportation
6/1/2017
This white paper addresses the importance of the interaction between transportation electrification and the electric power grid. Grid investments that support plug-in electric vehicle (PEV) deployments as a part of planned modernization efforts can enable a more efficient and cost-effective transition to electric transportation and allow investor-owned electric companies and public power companies to realize new revenue resources in times of flat or declining loads. This paper discusses the challenges and opportunities associated with an increase in PEV adoption and how working together both sectors stand to benefit from closer integration.
Authors: Graham, R.L.; Francis, J.; Bogacz, R.J.
