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Clean Cities Coalitions 2017 Activity Report
5/14/2019
The U.S. Department of Energy's (DOE's) national network of Clean Cities Coalitions advance the nation's economic, environmental, and energy security by supporting local actions to promote the use of domestic fuels within transportation. The nearly 100 Clean Cities coalitions, whose territory covers 80% of the U.S. population, bring together stakeholders in the public and private sectors to use alternative and renewable fuels, idle-reduction (IR) measures, fuel economy improvements, and new transportation technologies as they emerge. To ensure success, coalitions leverage a robust set of expert resources and tools provided by national laboratories and DOE. Each year, Clean Cities coordinators submit annual reports of their activities and accomplishments for the previous calendar year. Data and information are submitted via an online tool that is maintained as part of the Alternative Fuels Data Center (AFDC) at the National Renewable Energy Laboratory (NREL). Coordinators submit a range of data that characterize the membership, funding, projects, and activities of their coalitions. They also submit data about sales of alternative fuels; use of alternative fuel vehicles (AFVs), plug-in electric vehicles (PEVs), and hybrid electric vehicles (HEVs); IR initiatives; fuel economy improvement activities; and programs to reduce vehicle miles traveled (VMT). NREL analyzes the submitted data to determine how broadly energy use in the U.S. has shifted due to coalition activities, which are summarized in this report.
Authors: Johnson, C.; Singer, M.
Energy Implications of Current Travel and the Adoption of Automated Vehicles
4/29/2019
Current travel patterns and energy usage could be dramatically disrupted by new vehicle technologies, specifically in the case of automated vehicle (AV) technology. AV adoption could have a wide range of potential energy implications, depending on their usage and the efficiency of the AVs. The National Renewable Energy Laboratory conducted a survey to better understand which groups of people will likely adopt AV technology first, how respondents currently travel, and how respondents may change their travel patterns if AVs are widely adopted. Findings from this study are intended to provide an additional resource for model projections used by researchers to understand how transportation innovations may affect travel behaviors in the coming decades.
Authors: Fleming, K.; Singer, M.
Screening of Potential Biomass-Derived Streams as Fuel Blendstocks for Mixing Controlled Compression Ignition Combustion; SAE Technical Paper No. 2019-01-0570
4/2/2019
Mixing controlled compression ignition, i.e., diesel engines are efficient and are likely to continue to be the primary means for movement of goods for many years. Low-net-carbon biofuels have the potential to significantly reduce the carbon footprint of diesel combustion and could have advantageous properties for combustion, such as high cetane number and reduced engine-out particle and NOx emissions. We developed a list of over 400 potential biomass-derived diesel blendstocks and populated a database with the properties and characteristics of these materials. Fuel properties were determined by measurement, model prediction, or literature review. Screening criteria were developed to determine if a blendstock met the basic requirements for handling in the diesel distribution system and use as a blend with conventional diesel. Criteria included cetane number =40, flashpoint =52 degrees C, and boiling point or T90 =338 degrees C. Blendstocks needed to be soluble in diesel fuel, have a toxicity no worse than conventional diesel, not be corrosive, and be compatible with fuel system elastomers. Additionally, cloud point or freezing point below 0 degrees C was required. Screening based on blendstock properties produced a list of 12 that were available as fuels or reagent chemicals or could be synthesized by biofuels production researchers. This group included alkanes, alcohols, esters, and ethers. These candidates were further examined for their impact fuel properties upon blending with a conventional diesel fuel. Blend properties included cetane number, lubricity, conductivity, oxidation stability, and viscosity. Results indicate that all 12 candidates can meet the basic requirements for diesel fuel blending, although in some cases would require additive treatment to meet requirements for lubricity, conductivity, and oxidation stability.
Authors: Fioroni, G.; Fouts, L.; Luecke, J.; Vardon, D.; Huq, N.; Christensen, E.; Huo, X.; Alleman, T.; McCormick, R.; Kass, M.; Polikarpov, E.; Kukkadapu, G.; Whitesides, R.A.
Feasibility Analysis of Taxi Fleet Electrification using 4.9 Million Miles of Real-World Driving Data; SAE Paper No. 2019-01-0392
4/2/2019
Ride hailing activity is rapidly increasing, largely due to the growth of transportation network companies such as Uber and Lyft. However, traditional taxi companies continue to represent an important mobility option for travelers. Columbus Yellow Cab, a taxi company in Columbus, Ohio, offers traditional line-of-sight hailing as well as digital hailing through a mobile app. Data from Columbus Yellow Cab was provided to the National Renewable Energy Laboratory to analyze the potential for taxi electrification. Columbus Yellow Cab data contained information describing both global positioning system trajectories and taxi meter information. The data spanned a period of 13 months, containing approximately 70 million global system positioning system points, 840 thousand trips, and 170 unique vehicles. A variety of scenarios were evaluated using Columbus Yellow Cab data and the Electric Vehicle Infrastructure Projection Tool (EVI-Pro) to understand challenges and opportunities associated with operating an electrified taxi fleet. Two main factors-access to home charging and vehicle specifications-are shown to be major variables affecting successful electric fleet operation. The analysis indicates that 95.7% of taxi travel days can be successfully completed by a 250-mile-range electric vehicle assuming access to overnight and public charging infrastructure. However, when no overnight access is available to fleet vehicles, only 39.9% of taxi travel days are possible with 250-mile range electric vehicles. An additional scenario, reducing the vehicle range from 250 miles to 100 miles (while controlling for infrastructure access and permitting overnight charging) resulted in only 34.4% of taxi travel days being completed.
Authors: Moniot, M.; Rames, C.; Burrell, E.
Next-Generation Grid Communications for Residential Plug-in Electric Vehicles
1/25/2019
As residential plug-in electric vehicle (PEV) charging loads increase, they represent significant contributions to local distribution circuits, and if not managed, can have negative effects on local electricity grid stability. For residential PEV participation to be effective for grid stabilization, it is key to have detailed data collection, coordination at charging stations owned by different parties, sensitivity to each driver’s needs and preferences, and real-time understanding of each vehicle’s state of charge or charge necessary. This pilot project tested the technology ecosystems required to handle adding significant PEV load to the grid.
Authors: Patadia, S.; Rodine, C.
MOVES Activity Updates Using Fleet DNA Data: Interim Report
1/16/2019
The U.S. Environmental Protection Agency's Motor Vehicle Emissions Simulator (MOVES) is a publicly available tool used by researchers and policy makers to help understand motor vehicle emission sources at national, county, and project levels. However, estimates of heavy-duty activity (MOVES2014), have been identified as areas needing improvement. The start activities in MOVES2014 are calculated using a limited data set, prompting the concern that inventory values are not representative. In addition, MOVES2014 is believed to underestimate heavy-duty activity that is not captured in the current drive cycles used to represent on-network activity. For example, MOVES2014 does not account for work-day idling activity that takes place on off-network roads, such as at a distribution center while the truck is queuing or during loading and unloading. Under the guidance and expertise of the EPA, the National Renewable Energy Laboratory has leveraged its extensive Fleet DNA database of heavy-duty vehicles to reinforce the data set behind the next-generation MOVES model and enhance idle activity and start fractions using six heavy-duty vehicle classes. The data available in Fleet DNA from 420 conventional, diesel powered vehicles provided over 120,000 hours of operation. Start fraction, soak fraction, and idle fraction by hour of the day were derived for each source type, state, and vocation, and results were provided in the form of .CSV files representing MOVES table inputs. This midterm report details these results providing graphical analysis and context for the start, soak, and idle distributions.
Authors: Kotz, A.; Kelly, K.
Technology Maintenance Readiness Guide for Zero-Emission Buses
1/10/2019
Transit agencies all over the United States are deploying zero-emission buses (ZEBs), including battery electric buses and fuel cell electric buses. Air quality is the primary driver for adopting ZEBs, especially in states where legislation has been passed to regulate vehicle emissions. The U.S. Department of Energy, through its National Renewable Energy Laboratory (NREL), tracks the progress of these advanced technologies as they are being developed and demonstrated. NREL works with transit agencies and their manufacturing partners to conduct independent third-party evaluations to validate performance under real-world service and report on the status of the technologies toward entering the market. The results are intended to help transit agencies understand the technology status and make informed purchase decisions.
Clean Cities Coalitions 2016 Activity Report
10/10/2018
The U.S. Department of Energy's (DOE's) national network of Clean Cities Coalitions advance the nation's economic, environmental, and energy security by supporting local actions to promote the use of domestic fuels within transportation. The nearly 100 Clean Cities coalitions, whose territory covers 80% of the U.S. population, bring together stakeholders in the public and private sectors to use alternative and renewable fuels, idle-reduction (IR) measures, fuel economy improvements, and new transportation technologies as they emerge. To ensure success, coalitions leverage a robust set of expert resources and tools provided by national laboratories and DOE. Each year, Clean Cities coordinators submit annual reports of their activities and accomplishments for the previous calendar year. Data and information are submitted via an online tool that is maintained as part of the Alternative Fuels Data Center (AFDC) at the National Renewable Energy Laboratory (NREL). Coordinators submit a range of data that characterize the membership, funding, projects, and activities of their coalitions. They also submit data about sales of alternative fuels; use of alternative fuel vehicles (AFVs), plug-in electric vehicles (PEVs), and hybrid electric vehicles (HEVs); IR initiatives; fuel economy improvement activities; and programs to reduce vehicle miles traveled (VMT). NREL analyzes the submitted data to determine how broadly energy use in the U.S. has shifted due to coalition activities, which are summarized in this report.
Authors: Johnson, C.; Singer, M.
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.
Ethanol Basics
9/11/2018
Ethanol is a widely used, domestically produced renewable fuel made from corn and other plant materials. Ethanol can be blended with gasoline in different amounts. In fact, more than 98% of gasoline sold in the United States contains ethanol to oxygenate the fuel and help to reduce air pollution. Using ethanol in fuel also helps the nation increase the use of domestic alternative fuels, thereby potentially reducing reliance on imported oil. Gasoline and gasoline blendstocks can also use ethanol as an octane enhancer to increase vehicle performance.
A Life-Cycle Analysis of the Greenhouse Gas Emissions from Corn-Based Ethanol
9/5/2018
This analysis, conducted by ICF for the U.S. Department of Agriculture. This report has analyzed the current GHG profile of U.S. corn ethanol and two projected emissions profiles for 2022. The starting point is the GHG life-cycle analysis (LCA) done by the U.S. Environmental Protection Agency (EPA) in 2010 for U.S. corn ethanol as part of its Regulatory Impact Analysis (RIA) for the Revised Renewable Fuel Standard (RFS2). In the RIA, EPA projected that in 2022, the life cycle emissions associated with ethanol would be 21 percent lower than those of an energy equivalent quantity of gasoline.
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.
Economy and Emissions Impacts from Solazyme Fuel in UPS Delivery Vehicles
8/10/2018
To improve understanding of the potential fuel economy and emissions impacts from switching a fleet of vehicles from conventional petroleum diesel to synthetic renewable diesel, the National Renewable Energy Laboratory (NREL) conducted fuel economy and emissions analyses at NREL's Renewable Fuels and Lubricants (ReFUEL) Laboratory. Representative test cycles were developed based on real-world data from six package delivery vehicles and six class 8 day-cab tractors operated by UPS in the Dallas, Texas, area. A three-week in-field data collection period yielded 170 days of real-world vehicle operations data that NREL used to select representative standard drive cycles for testing. Fuel economy and emissions tests at the ReFUEL Laboratory showed that, in general, when switching from conventional diesel to renewable diesel observed changes in tailpipe carbon dioxide (CO2), fuel consumption, and fuel economy are primarily driven by changes in fuel properties such as the hydrogen-to-carbon ratio, density, and lower heating value (LHV). The vehicles tested with the renewable diesel showed a consistent 4.2% reduction in tailpipe CO2 emissions, but a 3.5%-4.8% reduction in fuel economy compared with local pump diesel. This is consistent with the 4.2% lower volumetric LHV of the sourced renewable diesel compared to the pump diesel. The UPS package car tested on renewable diesel also demonstrated a 4.1% oxides of nitrogen (NOx) reduction. NOx emissions from the UPS selective-catalyst-reduction-equipped tractor were an order of magnitude lower than the package car but showed relatively higher variability in results from cycle to cycle.
Authors: Kelly, K.; Ragatz, A.
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.
