Publications

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.

Medium Truck Duty Cycle Data from Real-World Driving Environments: Project Final Report

11/1/2012

Since the early part of the 20th century, the US trucking industry has provided a safe and economical means of moving commodities across the country. At present, nearly 80% of US domestic freight movement involves the use of trucks. The US Department of Energy (DOE) is spearheading a number of research efforts to improve heavy vehicle fuel efficiencies. This includes research in engine technologies (including hybrid and fuel cell technologies), lightweight materials, advanced fuels, and parasitic loss reductions. In addition, DOE is developing advanced tools and models to support heavy vehicle research and is leading the 21st Century Truck Partnership and the SuperTruck development effort. Both of these efforts have the common goal of decreasing the fuel consumption of heavy vehicles. In the case of SuperTruck, a goal of improving the overall freight efficiency of a combination tractor-trailer has been established.

This Medium Truck Duty Cycle (MTDC) project is a critical element in DOE's vision for improved heavy vehicle energy efficiency; it is unique in that there is no other existing national database of characteristic duty cycles for medium trucks based on collecting data from Class 6 and 7 vehicles. It involves the collection of real-world data on medium trucks for various situational characteristics (e.g., rural/urban, freeway/arterial, congested/free-flowing, good/bad weather) and looks at the unique nature of medium trucks' drive cycles (stop-and-go delivery, power takeoff, idle time, short-radius trips). This research provides a rich source of data that can contribute to the development of new tools for FE and modeling, provide DOE a sound basis upon which to make technology investment decisions, and provide a national archive of real-world-based medium-truck operational data to support energy efficiency research. The MTDC project involved a two-part field operational test (FOT). For the Part-1 FOT, three vehicles each from two vocations (urban transit and dry-box delivery) were instrumented for the collection of one year of operational data. The Part-2 FOT involved the towing and recovery and utility vocations for a second year of data collection.

Authors: Lascurain, M.B., Franzese, O., Capps, G., Siekmann, A., Thomas, N., LaClair, T., Barker, A., Knee, H.

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.

Coca-Cola Refreshments Class 8 Diesel Electric Hybrid Tractor Evaluation: 13-Month Final Report.

8/1/2012

This 13-month evaluation used five Kenworth T370 hybrid tractors and five Freightliner M2106 standard diesel tractors at a Coca Cola Refreshments facility in Miami, Florida. The primary objective was to evaluate the fuel economy, emissions, and operational field performance of hybrid electric vehicles when compared to similar-use conventional diesel vehicles. A random dispatch system ensures the vehicles are used in a similar manner. GPS logging, fueling, and maintenance records and laboratory dynamometer testing are used to evaluate the performance of these hybrid tractors. Both groups drive similar duty cycles with similar kinetic intensity (0.95 vs. 0.69), average speed (20.6 vs. 24.3 mph), and stops per mile (1.9 vs. 1.5). The study demonstrated the hybrid group had a 13.7% fuel economy improvement over the diesel group. Laboratory fuel economy and field fuel economy study showed similar trends along the range of KI and stops per mile. Hybrid maintenance costs were 51% lower per mile; hybrid fuel costs per mile were 12% less than for the diesels; and hybrid vehicle total cost of operation per mile was 24% less than the cost of operation for the diesel group.

Authors: Walkowicz, K.; Lammert, M.; Curran, P.

Analyzing Vehicle Fuel Saving Opportunities through Intelligent Driver Feedback

4/16/2012

Driving style changes, e.g., improving driver efficiency and motivating driver behavior changes, could deliver significant petroleum savings. This project examines eliminating stop-and-go driving and unnecessary idling, and also adjusting acceleration rates and cruising speeds to ideal levels to quantify fuel savings. Such extreme adjustments can result in dramatic fuel savings of over 30%, but would in reality only be achievable through automated control of vehicles and traffic flow. In real-world driving, efficient driving behaviors could reduce fuel use by 20% on aggressively driven cycles and by 5-10% on more moderately driven trips. A literature survey was conducted of driver behavior influences, and pertinent factors from on-road experiments with different driving styles were observed. This effort highlighted important driver influences such as surrounding vehicle behavior, anxiety over trying to get somewhere quickly, and the power/torque available from the vehicle. Existing feedback approaches often deliver efficiency information and instruction. Three recommendations for maximizing fuel savings from potential drive cycle improvement are: 1) leveraging applications with enhanced incentives, 2) using an approach that is easy and widely deployable to motivate drivers, and 3) utilizing connected vehicle and automation technologies to achieve large and widespread efficiency improvements.

Authors: Gonder, J.; Earleywine, M.; and Sparks, W.

Notes: Posted with permission. Presented at the 2012 SAE World Congress and Exhibition, April 24-26, 2012, Detroit, Michigan.

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.

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.

FedEx Express Gasoline Hybrid Electric Delivery Truck Evaluation: 12-Month Report

1/1/2011

This document presents the final results of a technology evaluation of gasoline hybrid electric parcel delivery trucks operated by FedEx Express in and around Los Angeles, California. FedEx Express is a large commercial fleet that operates more than 30,000 motorized vehicles and has hybrid electric (diesel and gasoline) vehicles currently in service. FedEx Express has deployed 20 gasoline hybrid electric vehicles (gHEVs) on parcel delivery routes in the Sacramento and Los Angeles areas. These gHEVs (Figure 1) are built upon a Ford E-450 strip chassis, and each vehicle is powered by a Ford 5.4L gasoline engine and Azure Dynamics, Inc. (AZD) Balance Hybrid System. Additional vehicle information is discussed in subsequent sections, while the specifics of the hybrid system evaluated are presented in Table 1. FedEx Express was the domestic launch customer for the AZD Balance Hybrid electric product.

Authors: Barnitt, R.

To Idle or Not to Idle: That is the Question

11/1/2010

Should I idle my car to warm it up before I drive? Should I shut the engine off while waiting to pick up a passenger or for a train to go by? Is it better to pick up food at a drive-through or to park and go into the restaurant? These are common questions that people ask when they want to know more about how to drive "green." There are conflicting answers in the literature, which has led to confusion. This poster presents the results of measurements performed on both diesel and gasoline passenger vehicles at Argonne National Laboratory. The answers are found to depend on vehicle type, ambient temperature, time, local laws, and what criteria are used to define "green."

An Action Plan for Cars: The Policies Needed to Reduce U.S. Petroleum Consumption and Greenhouse Gas Emissions

12/1/2009

Reducing petroleum consumption and GHG emissions from cars and light?]duty trucks in the United States over the next several decades requires that we implement a clear and coordinated set of policies now. This report describes a portfolio of policies which, in the view of the authors, is needed to put personal vehicle transportation on the road to sustainability in the longer term. To incentivize adoption of more fuel efficient vehicles, we propose coupling existing near?]term fuel economy standards with a feebate incentive program and gradual increases in fuel taxes. We further propose driver education initiatives that would give vehicle owners information on how to maximize fuel savings in their purchase and driving decisions. Finally, we underscore the need for a long?]term strategy for fuels that evaluates fuels?]related programs based on their contribution to reducing life?]cycle petroleum consumption and greenhouse gas (GHG) emissions. Together, these policies offer a robust plan of action that will focus and streamline current efforts to achieve these two important national goals. Perhaps most importantly, this plan lays a much?]needed foundation for a comprehensive, adaptable long?]term policy effort. A more detailed summary of the recommended set of policy measures can be found in Section 2.

Authors: Heywood, J.; Baptista, P.; Berry, I.; Bhatt, K.; Cheah, L.; De Sisternes, F.; Karplus, V.; Keith, D.; Khusid, M.; MacKenzie, D.; McAulay, J.

Clean Cities Annual Metrics Report 2008

9/1/2009

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. Approximately 412 million gallons of gasoline were displaced through the Clean Cities efforts in 2008?14% more than in 2007. This displacement represents the combined results of the activities reported by coalitions (as analyzed by NREL) and the impacts of the Fuel Economy Guide and related activities (as estimated by ORNL). Three major changes were made to the Clean Cities survey this year: E10 is no longer counted toward petroleum displacement goals, coordinators no longer relied on a default assumption for the percent of time flex-fueled vehicles used alternative fuel, and B20 was moved from the AFV to the blends category. The first of these changes substantially reduced the reported petroleum displacement by blends from what they otherwise would have been in 2008. AFVs still accounted for the largest share (48%) of the total 412-million-gallon displacement. Fuel economy impacts (combined impacts of coalition and ORNL activity) were responsible for displacing 129 million gallons. The use of biofuels (ethanol and biodiesel) as fuels for AFVs and in low-level biodiesel blends displaced 100 million gallons, or 24% of the total, and idle reduction and HEV technologies combined to displace 20 million gallons. 2008 was the first year that greenhouse gas (GHG) reductions were estimated for Clean Cities activities. The program kept a total of 2.7 million tons of carbon dioxide equivalent (CO2e) from being emitted to the atmosphere?the equivalent of removing over 507,000 passenger cars from U.S. roads.

Authors: Bergeron, P.; Johnson, C.

Compendium of Regulatory Language of U.S. Idle Ordinances and Laws

2/1/2009

Beginning with EPA's model state idling law, this document presents the regulatory language for all known city, county, multi-jurisdictional, and statewide idle laws across the United States. The regulatory language presented represents idle laws as incorporated by the controlling authorityat the time of collation. These laws vary in their prescribed maximum idle times, number and type of exceptions, and geographic scope. They are presented so that an interested party can use these laws to help guide creation of idle laws that suit their area. Pdf includes an interactive contents page to direct reader to state and city.

School Bus Idling Reduction: Project Report and Implementation Guide for Oklahoma School Districts

1/1/2009

School bus idling wastes fuel and financial resources while producing exhaust emissions that are harmful to human health and the environment. Beginning in late 2006, the Association of Central Oklahoma Governments, Choctaw-Nicoma Park Public Schools, and the Oklahomas Department of Environmental Quality undertook a two-year project to determine the extend of fuel and emissions savings that Oklahoma school district might expect by instituting a maximum five-minute school bus idling policy. This report offers the study's findings to public school districts in Oklahoma and elsewhere. Results indicate that for every five minutes of daily idling time reduced over the course of a school year, 7.5 gallons of fuel per bus can be saved for a collective savings of more than 58,000 gallons of diesel fuel saved annually.

Energy Use and Emissions Comparison of Idling Reduction Options for Heavy-Duty Diesel Trucks

11/15/2008

Pollution and energy analyses of different idling reduction (IR) technologies have been limited to localized vehicle emissions and neglected upstream energy use and regional emissions. In light of increasing regulation and government incentives for IR, we analyzed the full-fuel-cycle effects of contemporary approaches. Our analysis incorporates direct impacts at the truck and upstream energy use and emissions estimates from the GREET model with published climate and vehicle operation data. We compared emissions, energy use, and proximity to urban populations for nine alternatives, including idling, electrified parking spaces, auxiliary power units, and several combinations of these.

Petroleum Reduction Planning Tool

11/1/2008

The Petroleum Reduction Planning Tool helps fleets, consumers, and business owners create a strategy to reudce conventional fuel use in fleet and personal vehicles. This interactive tool allows users to evaluate and calculate petroleum reductions by choosing one or a combination of methods.