Publications

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration Results: Fourth Report

7/1/2015

This report presents results of a demonstration of fuel cell electric buses (FCEB) operating in Oakland, California. Alameda-Contra Costa Transit District (AC Transit) leads the Zero Emission Bay Area (ZEBA) demonstration, which includes 12 advanced-design fuel cell buses and two hydrogen fueling stations. The ZEBA demonstration is the largest FCEB demonstration in the United States and involves five participating transit agencies. The ZEBA partners are collaborating with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory (NREL) to evaluate the buses in revenue service. NREL has published three previous reports, in August 2011, July 2012, and May 2014, describing operation of these buses. New results in this report provide an update covering data from November 2013 through December 2014.

Authors: Eudy, L.; Post, M.

Strategic Planning to Implement Publicly Available EV Charging Stations: A Guide for Businesses and Policymakers

7/1/2015

This guide, prepared for the National Association of State Energy Officials, answers questions that private investors and state and local agencies, such as state energy offices, may have in deciding whether and to what extent they should invest in publicly available charging infrastructure. It demonstrates that with continued public support in the near term, new business models could gradually make publicly available charging projects profitable for private businesses without additional government interventions.

Authors: Nigro, N.; Welch, D.; Peace, J.

Strategic Planning to Enable ESCOs to Accelerate NGV Fleet Deployment: A Guide for Businesses and Policymakers

7/1/2015

This guide, prepared for the National Association of State Energy Officials, addresses questions that private investors and state and local agencies may have about key considerations and strategies for deploying NGVs in public and private fleets. The guide analyzes a range of scenarios for tractor- trailer truck, school bus, and light-duty vehicle fleets. Each scenario estimates the potential for NGVs to achieve net cost savings compared to conventional vehicles. Although switching to natural gas can lower costs, many fleet managers have not converted their fleets to NGVs. The business model that energy service companies (ESCOs) apply to energy efficiency projects may help fleet managers transition to NGV projects and realize these potential cost savings.

Authors: Nigro, N.; Welch, D.; Park, J.E.

Characterize the Demand and Energy Characteristics of Direct Current Fast Chargers

6/1/2015

The EV Project partnered with city, regional and state governments, utilities, and other organizations in 18 cities to deploy about 12,500 public and residential charging stations. It also demonstrated 8,650 plug-in electric vehicles. The focus of this paper is to identify the impact of direct current (DC) fast chargers charging on the total system load. It also identifies the characteristics of the aggregated group of DC fast chargers and a single typical DC fast charger and its charge profile or load duration curve.

E15 and Infrastructure

5/28/2015

This report explores the compatibility of refueling station equipment with E15--a 15% ethanol and 85% gasoline blend intended for use in conventional gasoline light duty vehicles model year 2001 or newer. The report includes background information on E15, a literature review seeking to identify issues during the nationwide deployment of E10, a diagram of all station equipment and a supporting table with each piece of equipment, common materials, purpose, and third-party listings for ethanol. The appendices include lists of compatible equipment.

Authors: Moriarty, K.; Yanowitz, J.

Clean Cities Alternative Fuel Price Report, April 2015

5/28/2015

The Clean Cities Alternative Fuel Price Report for April 2015 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, 2015 and April 15, 2015, 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 1 reports that the nationwide average price (all amounts are per gallon) for regular gasoline has increased 12 cents from $2.30 to $2.42; diesel decreased 18 cents from $3.06 to $2.88; CNG price decreased 2 cents from $2.11 to $2.09; ethanol (E85) decreased 8 cents from $2.21 to $2.13; propane increased 1 cent from $2.92 to $2.93; and biodiesel (B20) has decreased 26 cents from $3.18 to 3.92.

According to Table 2, CNG is $.33 less than gasoline on an energy-equivalent basis, while E85 is $0.35 more than gasoline on an energy-equivalent basis.

Authors: Bourbon, E.

What were the Cost Drivers for the DC Fast Charging Installations?

5/12/2015

The EV Project partnered with city, regional and state governments, utilities, and other organizations in 18 cities to deploy about 12,500 public and residential charging stations. It also demonstrated 8,650 plug-in electric vehicles. This evaluation reviews not only the costs and site conditions associated with the 111 DC fast chargers deployed during the EV Project, but also includes estimates obtained for another 50+ DC fast charger sites that were planned, but were not installed.

Idling Reduction for Personal Vehicles

5/7/2015

Fact sheet on reducing engine idling in personal vehicles. Idling your vehicle--running your engine when you're not driving it--truly gets you nowhere. Idling reduces your vehicle's fuel economy, costs you money, and creates pollution. Idling for more than 10 seconds uses more fuel and produces more pollutants that contribute to smog than stopping and restarting your engine does.

Idling Reduction for Emergency and Other Service Vehicles

5/7/2015

This is a fact sheet about reducing idling for emergency and service vehicles. Emergency vehicles, such as police cars, ambulances, and fire trucks, along with other service vehicles such as armored cars, are often exempt from laws that limit engine idling. However, these vehicles can save fuel and reduce emissions with technologies that allow them to perform vital services without idling.

Stop and Restart Effects on Modern Vehicle Starting System Components

4/28/2015

Many drivers of personal and commercial vehicles believe that turning the vehicle off and on frequently instead of idling will cause premature wear of the starter system (starter motor and starter battery). As a result, they are concerned that the replacement cost of the starter motor and/or battery due to increased manual engine cycling would be more than the cumulative cost of the fuel saved by not idling unnecessarily. A number of variables play a role in addressing this complex concern, including the number of starting cycles per day, the time between starting cycles, the intended design life of the starting system, the amount of fuel used to restart an engine, and the cumulative cost of the saved fuel. Qualitative and quantitative information from a variety of sources was used to develop a life-cycle economic model to evaluate the cost and quantify the realistic factors that are related to the permissible frequency of starter motor cycles for the average vehicle to economically minimize engine idle time. Annual cost savings can be calculated depending on shutdown duration and the number of shutdown cycles per day. Analysis shows that cost savings are realized by eliminating idling exceeding one minute by shutting down the engine and restarting it. For a typical motorist, the damage to starting system components resulting from additional daily start cycles will be negligible. Overall, it was found that starter life is mostly dependent on the total number of start cycles, while battery life is more dependent on ensuring a full charge between start events.

Authors: Windover, P.R.; Owens, R.J.; Levinson, T.M.; Laughlin, M.D.

What were the "Best Practices" Identified for Residential Charger Installations?

4/1/2015

This lessons learned white paper is based on data from the EV Project which enrolled 8,000 residential participants to install and use residential electric vehicle supply equipment. Along with background information and key conclusions, this paper describes observations regarding permitting practices and best installation conditions.

Building a Business Case for Compressed Natural Gas in Fleet Applications

3/19/2015

Abstract: Natural gas is a clean-burning, abundant, and domestically produced source of energy. Compressed natural gas (CNG) has recently garnered interest as a transportation fuel because of these attributes and because of its cost savings and price stability compared to conventional petroleum fuels. The National Renewable Energy Laboratory (NREL) developed the Vehicle Infrastructure and Cash-Flow Evaluation (VICE) model to help businesses and fleets evaluate the financial soundness of CNG vehicle and CNG fueling infrastructure projects.

Authors: Mitchell, G.

Clean Cities Alternative Fuel Price Report, January 2015

3/17/2015

The Clean Cities Alternative Fuel Price Report for January 2015 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 January 1, 2015 and January 15, 2015, 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 1 reports that the nationwide average price (all amounts are per gallon) for regular gasoline has decreased $1.04 from $3.34 to $2.30; diesel decreased 71 cents from $3.77 to $3.06; CNG price decreased 5 cents from $2.16 to $2.11; ethanol (E85) decreased 67 cents from $2.88 to $2.21; propane decreased 16 cents from $3.08 to $2.92; and biodiesel (B20) has decreased 63 cents from $3.81 to 3.18.

According to Table 2, CNG is $.19 less than gasoline on an energy-equivalent basis, while E85 is $0.82 more than gasoline on an energy-equivalent basis.

Authors: Bourbon, E.

Sample Workplace Charging Policy

3/2/2015

A sample workplace charging policy developed by the U.S. Department of Energy's Workplace Charging Challenge.

Authors: Workplace Charging Challenge

Effects of Regional Temperature on Electric Vehicle Efficiency, Range, and Emissions in the United States

2/11/2015

We characterize the effect of regional temperature differences on battery electric vehicle (BEV) efficiency, range, and use-phase power plant CO2 emissions in the U.S. The efficiency of a BEV varies with ambient temperature due to battery efficiency and cabin climate control. We find that annual energy consumption of BEVs can increase by an average of 15% in the Upper Midwest or in the Southwest compared to the Pacific Coast due to temperature differences. Greenhouse gas (GHG) emissions from BEVs vary primarily with marginal regional grid mix, which has three times the GHG intensity in the Upper Midwest as on the Pacific Coast. However, even within a grid region, BEV emissions vary by up to 22% due to spatial and temporal ambient temperature variation and its implications for vehicle efficiency and charging duration and timing. Cold climate regions also encounter days with substantial reduction in EV range: the average range of a Nissan Leaf on the coldest day of the year drops from 70 miles on the Pacific Coast to less than 45 miles in the Upper Midwest. These regional differences are large enough to affect adoption patterns and energy and environmental implications of BEVs relative to alternatives.

Authors: Yuksel, T.; Michalek, J. J.

Notes: This Environmental Science & Technology article is copyrighted by the American Chemical Society and only available by accessing it through ACS Publications.