Publications

BAE/Orion Hybrid Electric Buses at New York City Transit

1/1/2008

This report is part of a series of evaluation from the U.S. Department of Energy through the Advanced Vehicle Testing Activity (AVTA) at NREL. The role of AVTA is to bridge the gap between research and development and the commercial availability for advanced vehicle technologies that reduce petroleum use while meeting air quality standards.

DOE/NREL evaluated the original 10 prototype diesel-hybrid buses from Orion and BAE Systems operated by the New York City Transit Co. (NYCT) The next report focused on 10 new compressed natural gas (CNG) and 10 next generation diesel hybrid electric buses. In the present evaluation, the focus is on hybrid-electric transit buses (equipped with BAE Systems' HybriDrive propulsion system) purchased by NYCT in an order group of 200 (Gen II), and their performance during their first year of service.

Authors: Barnitt, R.

Energy Independence and Security Act of 2007

12/19/2007

The Energy Independence and Security Act (EISA) of 2007 put into law many of the provisions of Executive Order 13423. The goal of the EISA law is to move the United States toward greater energy independence and security, to increase production of clean renewable fuels, to protect consumers, to increase the efficiency of products, buildings, and vehicles, to promote research on and deploy greenhouse gas capture and storage options, and to improve the energy performance of the Federal Government.

On-Road Evaluation of Advanced Hybrid Electric Vehicles over a Wide Range of Ambient Temperatures

12/1/2007

Hybrid electric vehicles can provide increased fuel economy over convention gasoline powered vehicles but these advantages can be affected dramatically by wide variations in operating temperatures. To investigate cold and hot temperature effects on HEV operation and efficiency, an on-road evaluation protocol was defined and conducted over a 6-month study at widely varying temperatures ranging from -14 degrees C to 31 degrees C.

Authors: Carlson, R.; Duoba, M.; Bocci, D.; Lohse-Busch, H.

Plug-In Hybrid Electric Vehicles: How Does One Determine Their Potential for Reducing U.S. Oil Dependence?

12/1/2007

Estimation of the potential of plug-in hybrid electric vehicles' (PHEVs') ability to reduce U.S. gasoline use is difficult and complex. Although techniques have been proposed to estimate the vehicle kilometers of travel (VKT) that can be electrieid, these methods may be inadequate and/or inappropriate for early market introduction estimates. Factors that must be considered with respect to the PHEV itself include (1) kWh battery storage capability; (2) kWh/km depletion rate of the vehicle; (3) liters/km use of gasoline; (4) average daily kilometers diven; (5) annual share of trips exceeding the battery depletion distance; (6) driving cycle(s); (7) charger location; (8)charging rate. Taking into account PHEV design trade-off possibilities (kW vs. kWh of battery, in particular), this paper attempts to extract useful information relating to these topices. Costs per kWh of PHEVs capable of charge depleting (CD) all-electric range vs. those CD in "blended mode (CDB) are examined. Lifetime fuel savings of alternative PHEV operating/utilization strategies are compared to battery cost estimates.

Authors: Vyas, A.; Santini, D.; Duoba, M.; Alexander, M.

Impact of Component Size on Plug-In Hybrid Vehicle Energy Consumption Using Global Optimization

12/1/2007

Plug-in hybrid electric vehicles are a promising alternative to gas-only vehicles and offer the potential to greatly reduce fuel use in transportation. Their potential energy consumption is highly linked to the size of the components. This study focuses on the impact of the electric system energy and power on control and energy consumption. Based on a parallel pre-transmission architecture, several vehicles were modeled with an all-electric range from 5 to 40 miles on the Urban Dynamometer Driving Schedule to illustrate various levels of available electric energy. Five other vehicles were created, with various levels of power and the same battery energy. The vehicles were then simulated under optimal control on multiple combinations of cycle and distance by using a global optimization algorithm. The results from each optimization were analyzed to highlight control patterns. The potential minimal fuel consumption that can be achieved by each of them is presented in this report.

Authors: Karbowski, D.; Haliburton, C.; Rousseau, A.

Validation of Hydrogen Fuel Cell Vehicle and Infrastructure Technology

10/1/2007

Hydrogen-powered fuel cell vehicles could play a central role in future transportation system. They produce only electricity, heat, and water at point of use. They could also use predominantly domestic--potentially renewable--energy supplies instead of imported oil for transportation.

Through a 2003 competitive solicitation, DOE selected four automobile manufacturer/energy company teams to participate in the project--Chevron/Hyundai-Kia, DaimlerChrysler/BP, Ford/BP, and GM/Shell. DOE is cost-share fundung those teams to build small fleets of fuel-cell vehicles plus fueling stations to demonstrate their use in five regions of the United States.

Clean Cities Annual Metrics Report 2006

7/1/2007

Clean Cities coordinators submit an annual report of their activities and accomplishments for the previous calendar year. Coordinators submit a range of data that characterize the membership, funding, projects, and activities of their coalitions as well as data about sales of alternative fuel blends, deployment of alternative fuel vehicles, hybrid electric vehicles, idle reduction initiatives, and fuel economy activities. NREL analyzes the data and translates them into gasoline reduction impacts.

Survey results indicate that about 375 million gallons of gasoline were displaced through Clean Citiew efforts in 2006, 50 percent more than in 2005. Alternative fuel vehicles accounted for 71 percent of the reduction. Biofuels (ethanol and biodiesel) used in AFVs displaced 128 million gallons, 34 percent of the total 375 million.

Authors: Bergeron, P.; Putsche, V.

Plug-In Hybrid Electric Vehicle R&D Plan, External Draft

2/1/2007

The U.S. Department of Energy is supporting the development of hybrid vehicles that have the ability to operate in botn electrical/mechanical and electric-only modes recharging from a standard electric outlet. This is in line with President Bush's challenge of technology that would allow 40 miles electric range, enough to satisfy approximately 70 percent of daily U.S. travel. In May 2006, the FreedomCAR and Vehicle Technology Program convened a 2-day meeting to discuss a path forward. This report is the external draft of the research & development plan for the plug-in hybrid electric vehicle program.

Tackling Climate Change in the U.S.: Potential Carbon Emissions Reductions from Energy Efficiency and Renewable Energy by 2030

1/1/2007

Energy efficiency and renewable energy technologies have the potential to provide most, if not all, of the U.S. carbon emissions reductions that will be needed to help limit the atmospheric concentration of carbon dioxide to 450 to 500 ppm. The document includes a section on plug-in hybrid electric vehicles. This section focuses on plug-in hybrid electric vehicle technology, which adds additional battery capacity and charging capability to current hybrid electric vehicle technology. Plug-in vehicles thereby make possible substantial vehicle operation on energy derived from the electrical grid rather than from gasoline.

Authors: Kutscher, C., Editor; Lilienthal,P.; Brown, H.

The Evolution of Powertrain Technology 2008 and Beyond: Engines, Hybrids, Battery Electric, Fuel Cells, Transmissions

1/1/2007

The objectives of this study were to provide automotive suppliers and OEMs with a set of plausible alternatives that cover the future vehicle market, crude oil prices, regulatory and business environment; provide an assessment of benefits and costs of various powertrain technologies; identify the technical and market barriers that must be overcome to bring these technologies to market; provide a forecast of the potential market share of these technologies.

Authors: Gott, P.; Linna, J-R; Mello, J.

Dynamic Programming Applied to Investigate Energy Management Strategies for a Plug-In HEV.

10/23/2006

This paper explores two basic plug-in hybrid electric vehicle energy management strategies: an electric vehicle centric control strategy and an engine-motor blended control strategy.

Authors: O'Keefe, M.P.; Markel, T.

Cost-Benefit Analysis of Plug-In Hybrid Electric Vehicle Technology

10/23/2006

This paper presents a comparison of vehicle purchase and energy costs, and fuel-saving benefits of plug-in hybrid electric vehicles relative to hybrid electric and conventional vehicles.

Authors: Simpson, A.

Model Year 2007: Alternative Fuel and Advanced Technology Vehicles

10/1/2006

This document provides facts and figures for all model year 2007 alternative fuel and advanced technology vehicles (including hybrid electric cars) available to fleet buyers and the general public.

Plug-In HEV Vehicle Design Options and Expectations

9/27/2006

Presentation provides an overview of plug-in hybrid electric vehicle (PHEV) design options and expections.

Authors: Markel, T.

King County Metro Transit: Allison Hybrid Electric Transit Bus Laboratory Testing

9/1/2006

The National Renewable Energy Laboratory's ReFUEL facility conducted chassis dynamometer testing of two 60-foot articulated transit buses, one conventional and one hybrid. Both test vehicles were 2004 New Flyer buses powered by Caterpillar C9 8.8L engines, with the hybrid vehicle incorporating a GM-Allison advanced hybrid electric drivetrain. Both vehicles also incorporated an oxidizing diesel particulate filter. The hybrid vehicle demonstrated the greatest improvement in fuel economy in the low speed, heavy stop-and-go driving conditions of the Manhattan (N.Y.)test cycle (74.6%), followed by the Orange County (Calif.) test cycle (50.6%), the Central Business District cycle (48.3%), and the King County (Wash.) Metro test cycle (30.3%). Emission trends were similar to fuel economy improvement trends. The hybrid shoed reductions in NOx emissions over the Manhattan cycle (38.7%), the Orange County cycle (28.6%), the Central Business District cycle (26.6%), and the King County test cycle (17.8%). Vehicle exhaust emissions, fuel consumption, and state of charge of the energy storage system were measured for repeated test conditions. The remainder of this document includes the experimental setup, test procedures, and results from vehicle testing performed at the NREL ReFUEL laboratory.

Authors: Hayes, R.R.; Williams, A.; Ireland, J.; Walkowicz, K.