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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.
Model Year 2018: Alternative Fuel and Advanced Technology Vehicles
8/7/2018
The fact sheet details the model, vehicle type, emission class, transmission type/speeds, engine size, and fuel economy of a variety of flexible fuel vehicles, hybrid electric vehicles, all-electric, and extended range electric vehicles, as well as CNG and propane vehicles.
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.
Clean Cities Alternative Fuel Price Report, April 2018
6/14/2018
The Clean Cities Alternative Fuel Price Report for April 2018 is a quarterly report on the prices of alternative fuels in the U.S. and their relation to gasoline and diesel prices. This issue describes prices that were gathered from Clean Cities coordinators and stakeholders between April 1, 2018 and April 16, 2018, and then averaged in order to determine regional price trends by fuel and variability in fuel price within regions and among regions. The prices collected for this report represent retail, at-the-pump sales prices for each fuel, including Federal and state motor fuel taxes.
Table 2 reports that the nationwide average price (all amounts are per gallon) for regular gasoline has increased 17 cents from $2.50 to $2.67; diesel increased 7 cents from $2.96 to $3.03; CNG increased 1 cent from $2.17 to $2.18; ethanol (E85) increased 15 cents from $2.06 to $2.21; propane remained the same at $2.83; and biodiesel (B20) increased 3 cents from 2.84 to $2.87.
According to Table 3, CNG is $.49 less than gasoline on an energy-equivalent basis, while E85 is $0.20 more than gasoline on an energy-equivalent basis.
Authors: Bourbon, E.
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.
State of the States: Fuel Cells in America 2017, 8th Edition
5/23/2018
This January 2018 report, the eighth in a series, provides a comprehensive analysis of state activities supporting fuel cell and hydrogen technology, including profiles of all 50 states with a catalog of recent installations, policies, funding, and deployments around the country.
Authors: Curtin, S.; Gangi, J.
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.
Determining Off-Cycle Fuel Economy Benefits of 2-Layer HVAC Technology. SAE Paper No. 2018-01-1368
4/12/2018
This work presents a methodology to determine the off-cycle fuel economy benefit of a 2-Layer HVAC system which reduces ventilation and heat rejection losses of the heater core versus a vehicle using a standard system. Experimental dynamometer tests using EPA drive cycles over a broad range of ambient temperatures were conducted on a highly instrumented 2016 Lexus RX350 (3.5L, 8 speed automatic). These tests were conducted to measure differences in engine efficiency caused by changes in engine warmup due to the 2-Layer HVAC technology in use versus the technology being disabled (disabled equals fresh air-considered as the standard technology baseline). These experimental datasets were used to develop simplified response surface and lumped capacitance vehicle thermal models predictive of vehicle efficiency as a function of thermal state. These vehicle models were integrated into a database of measured on road testing and coupled with U.S. typical meteorological data to simulate vehicle efficiency across seasonal thermal and operational conditions for hundreds of thousands of drive cycles. Fuel economy benefits utilizing the 2-Layer HVAC technology are presented in addition to goodness of fit statistics of the modeling approach relative to the experimental test data.
Authors: Jehlik, F.; Chevers, N.; Moniot, M.; Song, Y.; Hirabayashi, H.; Nomura, M.; Wood, E.
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.
Exploring Telematics Big Data for Truck Platooning Opportunities. SAE Paper No. 2018-01-1083
4/3/2018
NREL completed a temporal and geospatial analysis of telematics data to estimate the fraction of platoonable miles traveled by class 8 tractor trailers currently in operation. This paper discusses the value and limitations of very large but low time-resolution data sets, and the fuel consumption reduction opportunities from large scale adoption of platooning technology for class 8 highway vehicles in the US based on telematics data. The telematics data set consist of about 57,000 unique vehicles traveling over 210 million miles combined during a two-week period. 75% of the total fuel consumption result from vehicles operating in top gear, suggesting heavy highway utilization. The data is at a one-hour resolution, resulting in a significant fraction of data be uncategorizable, yet significant value can still be extracted from the remaining data. Multiple analysis methods to estimate platoonable miles are discussed. Results indicate that 63% of total miles driven at known hourly-average speeds happens at speeds amenable to platooning. When also considering availability of nearby partner vehicles, results indicate 55.7% of all classifiable miles driven were platoonable. Analysis also address the availability of numerous partners enabling platoons greater than 2 trucks and the percentage of trucks that would be required to be equipped with platooning equipment to realize more than 50% of the possible savings.
Authors: Lammert, M.P.; Bugbee, B.; Hou, Y.; Mack, A.; Muratori, M.; Holden, J.; Duran, A.; Swaney, E.
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.
