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Transitioning to zero-emission heavy-duty freight vehicles
9/26/2018
This report compares the evolution of heavy-duty diesel, diesel hybrid, natural gas, fuel cell, and battery electric technologies in the 2025-2030 timeframe. It synthesizes data from the research literature, demonstrations, and low-volume commercial trucks regarding their potential to deliver freight with zero tailpipe emissions. Additionally, it analyzes the emerging technologies by their cost of ownership and life-cycle greenhouse gas emissions for the three vehicle markets of China, Europe, and the United States.
Authors: Moultak, M.; Lutsey, N.; Hall, D.
Notes:
This copyrighted publication can be accessed on The International Council on Clean Transportation's website.
Policies that Impact the Acceleration of Electric Vehicle Adoption
9/26/2018
To better understand the influence of policy initiatives that relate to electric vehicles (EVs) have on accelerated deployment, this project focused on a number of successful public and private initiatives and policies designed to encourage the adoption of EVs and related infrastructure. This report highlights programs that have influenced adoption, provides a critique of best practices, and includes references to databases EV policy initiatives.
Authors: Kettles, C.
The Zero Emission Vehicle Regulation
8/24/2018
This fact sheet provides an overview of California’s zero-emission vehicle (ZEV) regulation, which is designed to achieve the state’s long-term emission reduction goals by requiring manufacturers to offer for sale specific numbers of the very cleanest cars available. The ZEV regulation has been adopted by other states.
Electrification Futures Study: Scenarios of Electric Technology Adoption and Power Consumption for the United States
8/8/2018
This report is the second publication in a series of Electrification Futures Study publications. The report presents scenarios of electric end-use technology adoption and resulting electricity consumption in the United States. The scenarios reflect a wide range of electricity demand growth through 2050 that result from various electric technology adoption and efficiency projections in the transportation, residential and commercial buildings, and industrial sectors.
Authors: Mai, T.; Jadun, P.; Logan, J.; McMillan, C.; Muratori, M.; Steinberg, D.; Vimmerstedt, L.; Jones, R.; Haley, B.; Nelson, B.
Workplace Charge Management with Aggregated Building Loads
8/1/2018
This paper was presented at the 2018 IEEE Transportation Electrification Conference and Expo (ITEC), 13-15 June 2018, Long Beach, California. It describes a workplace charge management system developed to control plug-in electric vehicle charging stations based on aggregated building loads. A system to collect information from drivers was also developed for better charge management performance since the present AC charging station standard does not provide battery state of charge information. First, simulations with uncontrolled charging data were conducted to investigate several scenarios and control methods, and then one method with the most power curtailment during peak load was selected for verification tests. This paper illustrates load reduction test results for 36 charging stations and real-time campus net load data.
Authors: Jun, M.; Meintz, A.
Notes:
This copyrighted publication can be viewed and purchased on the Institute of Electrical and Electronics Engineers's website.
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.
The Role of Demand-Side Incentives and Charging Infrastructure on Plug-in Electric Vehicle Adoption: Analysis of US States. Paper No. 074032
7/13/2018
In the U.S., over 400 state and local incentives have been issued to increase the adoption of plug-in electric vehicles (PEVs) since 2008. This article quantifies the influence of key incentives and enabling factors like charging infrastructure and receptive demographics on PEV adoption. The study focuses on three central questions. First, do consumers respond to certain types of state level vehicle purchase incentives? Second, does the density of public charging infrastructure increase PEV purchases? Finally, does the impact of various factors differ for plug-in hybrid electric vehicles (PHEV), battery electric vehicles (BEV) and vehicle attributes within each category? Based on a regression of vehicle purchase data from 2008 to 2016, we found that tax incentives and charging infrastructure significantly influence per capita PEV purchases. Within tax incentives, rebates are generally more effective than tax credits. BEV purchases are more affected by tax incentives than PHEVs. The correlation of public charging and vehicle purchases increases with the battery-only driving range of a PHEV, while decreasing with increasing driving range of BEVs. Results indicate that early investments in charging infrastructure, particularly along highways; tax incentives targeting BEVs at the lower end of the price premium and PHEVs with higher battery only driving range, and better reflection of the environmental cost of owning gasoline vehicles are likely to increase PEV adoption in the U.S.
Authors: Narassimhan, E.; Johnson, C.
Notes:
This journal article (Environmental Research Letters, Volume 13, Number 7) is copyrighted by IOP Publishing and can be downloaded from the IOPScience website.
Total Thermal Management of Battery Electric Vehicles (BEVs). SAE Paper No. 2018-37-0026
5/30/2018
The key hurdles to achieving wide consumer acceptance of battery electric vehicles (BEVs) are weather-dependent drive range, higher cost, and limited battery life. These translate into a strong need to reduce a significant energy drain and resulting drive range loss due to auxiliary electrical loads the predominant of which is the cabin thermal management load. Studies have shown that thermal subsystem loads can reduce the drive range by as much as 45% under ambient temperatures below -10 degrees C. Often, cabin heating relies purely on positive temperature coefficient (PTC) resistive heating, contributing to a significant range loss. Reducing this range loss may improve consumer acceptance of BEVs. The authors present a unified thermal management system (UTEMPRA) that satisfies diverse thermal and design needs of the auxiliary loads in BEVs. Demonstrated on a 2015 Fiat 500e BEV, this system integrates a semi-hermetic refrigeration loop with a coolant network and serves three functions: (1) heating and/or cooling vehicle traction components (battery, power electronics, and motor) (2) heating and cooling of the cabin, and (3) waste energy harvesting and re-use. The modes of operation allow a heat pump and air conditioning system to function without reversing the refrigeration cycle to improve thermal efficiency. The refrigeration loop consists of an electric compressor, a thermal expansion valve, a coolant-cooled condenser, and a chiller, the latter two exchanging heat with hot and cold coolant streams that may be directed to various components of the thermal system. The coolant-based heat distribution is adaptable and saves significant amounts of refrigerant per vehicle. Also, a coolant-based system reduces refrigerant emissions by requiring fewer refrigerant pipe joints. The authors present bench-level test data and simulation analysis and describe a preliminary control scheme for this system.
Authors: Chowdhury, S.; Leitzel, L.; Zima, M.; Santacesaria, M.; Titov, G.; Lustbader, J.; Rugh, J.; Winkler, J.; Khawaja, A.; Govindarajalu, M.
Foothill Transit Agency Battery Electric Bus Progress Report, Data Period Focus: Jan. 2017 through Dec. 2017
5/16/2018
This report summarizes results of a battery electric bus (BEB) evaluation at Foothill Transit, located in the San Gabriel Valley area of Los Angeles. Foothill Transit is collaborating with the California Air Resources Board and the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) to evaluate the buses in revenue service. The focus of this evaluation is to compare the performance and the operating costs of the BEBs to that of conventional technology buses and to track progress over time. Previous reports documented results from April 2014 through December 2016. This report extends the data analysis through December 2017. NREL plans to publish progress reports on the Foothill Transit fleet every six months through 2020.
Authors: Eudy, L.; Jeffers, 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.
The Dynamics of PEVs in the Secondary Market and Their Implications for Vehicle Demand, Durability, and Emissions
4/13/2018
California is one of the first markets in the world to have a significant secondary market for plug-in electric vehicles (PEVs). This study examines the status of the nascent secondary PEV market in California. It reviews who purchases these vehicles and how used PEVs are utilized. It also examines the role of PEV purchase incentives via surveys of used PEV buyers and by analyzing the purchase behavior for used vehicles nationwide and in California.
Authors: Turrentine, T.; Tal, G.; Rapson, D.
Range Extension Opportunities While Heating a Battery Electric Vehicle. SAE Paper No. 2018-01-0066
4/3/2018
The Kia Soul battery electric vehicle (BEV) is available with either a positive temperature coefficient (PTC) heater or an R134a heat pump (HP) with PTC heater combination (1). The HP uses both ambient air and waste heat from the motor, inverter, and on-board-charger (OBC) for its heat source. Hanon Systems, Hyundai America Technical Center, Inc. (HATCI) and the National Renewable Energy Laboratory jointly, with financial support from the U.S. Department of Energy, developed and proved-out technologies that extend the driving range of a Kia Soul BEV while maintaining thermal comfort in cold climates. Improved system configuration concepts that use thermal storage and waste heat more effectively were developed and evaluated. Range extensions of 5%-22% at ambient temperatures ranging from 5 degrees C to -18 degrees C were demonstrated. This paper reviews the three-year effort, including test data of the baseline and modified vehicles, resulting range extension, and recommendations for future actions.
Authors: Meyer, J.J.; Lustbader, J.; Agathocleous, N.; Vespa, A.; Rugh, J.; Titov, G.
Analysis of Fast Charging Station Network for Electrified Ride-Hailing Services. SAE Paper No. 2018-01-0667
4/3/2018
Today's electric vehicle (EV) owners charge their vehicles mostly at home and seldom use public direct current fast charger (DCFCs), reducing the need for a large deployment of DCFCs for private EV owners. However, due to the emerging interest among transportation network companies to operate EVs in their fleet, there is great potential for DCFCs to be highly utilized and become economically feasible in the future. This paper describes a heuristic algorithm to emulate operation of EVs within a hypothetical transportation network company fleet using a large global positioning system data set from Columbus, Ohio. DCFC requirements supporting operation of EVs are estimated using the Electric Vehicle Infrastructure Projection tool. Operation and installation costs were estimated using real-world data to assess the economic feasibility of the recommended fast charging stations. Results suggest that the hypothetical transportation network company fleet increases daily vehicle miles traveled per EV with less overall down time, resulting in increased demand for DCFC. Sites with overhead service lines are recommended for hosting DCFC stations to minimize the need for trenching underground service lines. A negative relationship was found between cost per unit of energy and fast charging utilization, underscoring the importance of prioritizing utilization over installation costs when siting DCFC stations. Although this preliminary analysis of the impacts of new mobility paradigms on alternative fueling infrastructure requirements has produced several key results, the complexity of the problem warrants further investigation.
Authors: Wood, E.; Rames, C.; Kontou, E.; Motoaki, Y.; Smart, J.; Zhou, Z.
Development of 80- and 100- Mile Work Day Cycles Representative of Commercial Pickup and Delivery Operation
4/3/2018
When developing and designing new technology for integrated vehicle systems deployment, standard cycles have long existed for chassis dynamometer testing and tuning of the powertrain. However, to this day with recent developments and advancements in plug-in hybrid and battery electric vehicle technology, no true 'work day' cycles exist with which to tune and measure energy storage control and thermal management systems. To address these issues and in support of development of a range-extended pickup and delivery Class 6 commercial vehicle, researchers at the National Renewable Energy Laboratory in collaboration with Cummins analyzed 78,000 days of operational data captured from more than 260 vehicles operating across the United States to characterize the typical daily performance requirements associated with Class 6 commercial pickup and delivery operation. In total, over 2.5 million miles of real-world vehicle operation were condensed into a pair of duty cycles, an 80-mile cycle and a 100-mile cycle representative of the daily operation of U.S. class 3-6 commercial pickup and delivery trucks. Using novel machine learning clustering methods combined with mileage-based weighting, these composite representative cycles correspond to 90th and 95th percentiles for daily vehicle miles traveled by the vehicles observed. In addition to including vehicle speed vs time drive cycles, in an effort to better represent the environmental factors encountered by pickup and delivery vehicles operating across the United States, a nationally representative grade profile and key status information were also appended to the speed vs. time profiles to produce a 'work day' cycle that captures the effects of vehicle dynamics, geography, and driver behavior which can be used for future design, development, and validation of technology.
Authors: Duran, A.; Li, K.; Kresse, J.; Kelly, K.
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.
