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5 CHAPTER ONE INTRODUCTION BACKGROUND Gasoline and diesel are the primary fuels used in the United States transportation sector, accounting for 93% of all energy use in light-, medium-, and heavy-duty vehicles (EIA 2016). Additionally, the transportation sector is a major contributor to greenhouse gas (GHG) and criteria pollutant emissions. A key strategy to address petroleum use and emissions from the transportation sector is to use alternative fuels (NAS 2013). Fleet vehicles are widely viewed as attractive markets for alternative fuels for the following reasons (DOE 2001; Sperling and Nesbitt 2001): â¢ Certain fleet vehicles, such as buses and shuttle buses, often have higher mileage than privately owned vehicles, mean- ing the environmental benefits are amplified when shifting vehicles to alternative fuels. â¢ Fleet procurement processes tend to enable longer planning horizons than individual consumers typically use. â¢ Fleet vehicles often can be centrally fueled, reducing fuel infrastructure costs. â¢ Airport vehicle fleets often have predictable duty cycles with efficient refueling operations but long idle periods and frequent stops near pedestrians. Although the costs and benefits of alternative fuels are fairly well understood, their use in airport fleets is not. This syn- thesis report compiles airport experiences with alternative fuels in airport-owned and airport-contracted vehicles, including shuttles, emergency response and security vehicles, and facility and maintenance vehicles. Insights provided in the report are designed to assist airports beginning new programs or modifying existing alternative fuel programs, and to help all airports understand the barriers and opportunities presented by alternative fuel use. During report development, airports in the United States and Canada were surveyed about a range of topics involving alternative fuel vehicles, including fuel and vehicle costs, infrastructure, procurement, administrative considerations, envi- ronmental impact analysis, and future interests. Following completion of the online survey, 16 of the participating airports were interviewed via teleconference, giving additional details about their alternative fuel programs. Together, the online survey results and teleconference discussions provided an array of insights about how alternative fuels are being used in airport-owned and airport-contracted vehicles. FUELS This report considers eight alternative fuels, as described in Table 2. These fuels were chosen based on their potential to reduce emissions and petroleum use, and on whether the general population has a firm understanding of their costs and ben- efits. Notably, ethanol was not included in the study because it has been widely used in the market since the 1980s, and only minimal training is needed for personnel to understand the operation of flex-fuel vehicles (i.e., those capable of running on up to 85% ethanol by volume). Similarly, simple hybrid-electric vehicles were not included because the driving experience and refueling operations are the same as those of a petroleum-fueled vehicle. However, vehicles capable of running on grid electricity or in hybrid-electric mode are included [e.g., plug-in hybrid electric vehicles (PHEVs)]. Table 3 provides qualita- tive information on each fuel, allowing for easy comparison of each fuelâs attributes and emissions. Chapter four discusses each of the fuels in greater detail.
6 VEHICLES Airports own, lease, or contract a variety of vehicles that support daily operations. This synthesis report separates airport fleet vehicles into three functional categories: (1) shuttles, (2) emergency response and security, and (3) facility and maintenance. The vehicles within each category have similar duty cycles and administrative managers. The purpose of these groupings is to make this report as organized and user-friendly as possible. Within each functional category, several individual vehicle types are discussed, as described in Table 4. Large commercial service airports have up to hundreds or even thousands of vehicles in their fleets. To demonstrate a âtypicalâ airport-owned vehicle fleet portfolio, Figure 2 shows the makeup of the vehicle fleet at Oakland International Airport, a midsize commercial service airport. The fleet makeup is diverse; 15 vehicle types are represented. Pickup trucks and sedans account for more than 50% of all airport-owned vehicles. FIGURE 2 Example of âtypicalâ airport-owned vehicle fleet (Source: Oakland International Airport). Note that Figure 2 does not show stationary equipment that uses transportation fuels (e.g., diesel-powered pressure washers). In addition, the figure does not reflect the total fuel consumption of the vehiclesâonly the number of vehicles. In most airport fleets, TABLE 2 DESCRIPTIONS OF FUEL TYPES INCLUDED IN STUDY Fuel Type Description Biodiesel Animal or vegetable oilâderived fuel made via transesterification process. Biodiesel is rarely used in its pure form (B100) and is often blended with conventional diesel (B2, B5, and B20, where the number following the âBâ is the percentage of biodiesel blended). Typically, biodiesel is not blended at levels above 20% without modification to the fuel storage tank and engine. In this report, the term âBiodieselâ refers to B2, B5, and B20 unless otherwise stated. Renewable Diesel Fuel made from waste oils, fats, and vegetable oils that can be blended directly with conventional diesel up to 100% with no modification to the engine. Also known as âgreen diesel.â Typically produced via hydrotreating process. Compressed Natural Gas (CNG) Fossil-based gaseous fuel, comprised mostly of methane. Renewable Natural Gas Fuel made from municipal solid waste and other bio-based feedstocks that is interchangeable with conventional natural gas and provides considerable greenhouse gas benefits, depending on the production process. Also known as âbio- methane.â Typically sourced via anaerobic digestion of municipal solid waste. Liquefied Natural Gas (LNG) Conventional natural gas converted to liquid form through cooling. Liquefied Petroleum Gas (LPG) Fossil-based fuel created as by-product of natural gas and petroleum refining. Delivered and stored as liquid fuel. Also known as propane fuel. Hydrogen Gaseous fuel typically used in fuel cell or direct combustion. Electricity Fuel from the electricity grid, stored aboard vehicles in batteries. For this report, includes all-electric vehicles and plug-in hybrid electric vehicles.
7 TABLE 3 QUALITATIVE COMPARISON OF ALTERNATIVE FUELS P as se ng er C ar Fuel Cost Vehicle Cost Fuel Availability Vehicle Availability GHG Emissions (kg/mi) Air Quality (Tailpipe Emissions Only) NOx (g/mi) PM2.5 (mg/mi) PM10 (mg/mi) CO (g/mi) Gasoline1 0.31 0.12 4.78 5.41 2.7 Hydrogen2 * 0.26 0 0 0 0 Electric3 0.21 0 0 0 0 H ea vy -D ut y P ic ku p T ru ck Fuel Cost Vehicle Cost Fuel Availability Vehicle Availability GHG Emissions (kg/mi) Air Quality (Tailpipe Emissions Only) NOx (g/mi) PM2.5 (mg/mi) PM10 (mg/mi) CO (g/mi) Diesel4 0.62 1.15 21.89 25.22 0.46 BD205 0.53 0.94 10.89 11.84 0.37 RD1006 0.44 0.94 10.89 11.84 0.37 CNG 0.55 0.46 10.16 11.48 7.49 LPG 0.55 0.46 10.16 11.48 7.49 RNG7 No data ** 0.09 0.46 10.16 11.48 7.49 T ra ns it B us Fuel Cost Vehicle Cost Fuel Availability Vehicle Availability GHG Emissions (kg/mi) Air Quality (Tailpipe Emissions Only) NOx (g/mi) PM2.5 (mg/mi) PM10 (mg/mi) CO (g/mi) Diesel4 3.12 1.17 21.29 23.14 0.52 BD205 2.68 1.17 21.29 23.14 0.52 RD1006 2.21 1.17 21.29 23.14 0.52 CNG 3.31 0.59 21.29 23.14 23.00 LNG 3.30 0.59 21.29 23.14 23.00 RNG7 No data ** 0.55 0.59 21.29 23.14 23.00 Electric3 1.50 0.00 0.00 0.00 0.00 Sources: Fuel cost: DOE 2017c; vehicle cost: ANL 2016b; fuel availability: DOE 2017b; vehicle availability: DOE 2017a; emissions: ANL 2016a; renewable natural gas GHG emissions: CARB n.d. Key: Worse than reference Slightly worse than reference Similar to reference Slightly improved over reference Improved over referenceReference fuel Colors should not be compared between vehicle types or columns. Notes: * Fuel currently available only in California. **Fuel available mainly on West Coast of the United States. 1. E10 gasoline. 2. Gaseous hydrogen from natural gas reforming using conventional material. 3. Electricity produced using average U.S. grid mix. 4. Low-sulfur diesel. 5. Biodiesel from average Midwest soybeans and transesterification. Mixed with low-sulfur diesel at a ratio of 20-80 biodiesel-diesel. 6. Renewable diesel from hydrotreated pyrolysis oil from forest residues. Vehicle uses 100% renewable diesel. 7. Renewable natural gas from landfill gas, upgraded to pipeline quality. TABLE 4 DESCRIPTIONS OF VEHICLE TYPES FROM SURVEY RESPONDENTS Functional Category Description and Use Shuttles Vehicles used primarily to move people (e.g., employees, passengers, tenants) between terminals, parking lots, or other loca- tions. Can be indoor or outdoor. Includes employee vehicle pool/car share vehicles. Vehicle types include buses (>40 pas- sengers), shuttle buses (<40 passengers), cut-aways, and vans. Emergency Response and Security Vehicles used primarily by emergency services or security personnel. Vehicle types include Airport Rescue and Firefighting vehicles, pickup trucks or sport utility vehicles (SUVs), sedans, carts (e.g., golf carts, shuttles), and ambulances. Facility/Maintenance Vehicles used primarily for operational support of the airport. Vehicle types include pickup trucks or SUVs, sedans, bucket trucks, dump trucks, utility trucks, forklifts, snow removal vehicles, sweepers, and garbage trucks.
8 the vast majority of fuel is used in the buses, shuttles, and vans, even though they represent a small percentage of the fleet. These vehicles have relatively low fuel economies and high vehicle miles traveled compared with other vehicles in the airport fleet. LITERATURE REVIEW Several publicly available websites and documents provide use- ful comparisons across alternative fuel and vehicle categories. For example, the U.S. Department of Energyâs (DOEâs) Alter- native Fuel Data Center provides data on all the fuels included in this report, including fuel costs, refueling station locations, and tools for fleet managers (DOE 2016a). A recent study by the National Academies of Science, Engineering, and Medicine (NAS) provides an all-encompassing examination of transitions to alternative fuels, including future performance of alternative fuel vehicles, costs, and barriers to implementation (NAS 2013). Alternative fuel studies that focus exclusively on fleet vehicles are less common. DOE (2001) summarized alternative fuel use at three case study airports and concluded that although some fuels can lead to cost savings compared with equivalent diesel vehicles, external funding for alternative fuel programs is critical to their success. ACRP Synthesis 24: Strategies and Financing Opportunities for Airport Environmental Programs (Molar 2011) provides a wealth of information on funding opportunities and strategies available to airports and applicable to alternative fuels. Sperling and Nesbitt (2001) examined the decision-making process of fleet managers and found that the most compelling attributes of alternative fuelsâsuch as the ability to reduce emissionsâare not important motivators for fleet managers, who are more likely to prioritize minimizing the cost for a given level of service. In addition, the authors observed that fleets often have short-term budgets relative to other larger organizations, making vehicles with long payback periods less appealing. Relatively little research has been conducted on the emissions benefits of alternative fuels at airports. One report, ACRP Web-Only Document 13: Alternative Fuels as a Means to Reduce PM2.5 Emissions at Airports (Pearce et al. 2012), investi- gates the potential PM2.5 (particulate matter with a diameter of 2.5 micrometers or less) emissions reductions from 18 differ- ent alternative fuels in aircraft, ground support equipment (GSE), and road vehicles. The report findings show that, at five case example airports, parking vehicles contribute a maximum of 2.0% of on-airport PM2.5 emissions (San Diego International Airport), and other non-GSE vehicles contribute a maximum of 3.0% (Hartsfield Atlanta International Airport). Airport GHG inventories also provide valuable data on emissions. They indicate that airport-owned and airport-contracted vehicle emissions contribute to a sizeable portion of the emissions over which an airport has direct control. Typically, inven- tories divide emissions into Scope 1, 2, and 3 (Kim et al. 2009): â¢ Scope 1 emissions are those under the direct control of the airport and include airport fleet vehicles. â¢ Scope 2 emissions result from electricity consumed by the airport but generated off-airport. â¢ Scope 3 emissions include all other emissions attributable to, but not directly generated by, the airport, such as those from aircraft, GSE, and employee commuting (WRI 2012). Fleet managers at airports have several tools at their disposal to compare alternative fuel emissions, learn about financing alternative fuels, and determine associated cost savings. These tools are highlighted in Table 5 along with additional tools that are not specific to determining the emissions or economics of alternative fuels, but nevertheless may be useful for airport managers. ORGANIZATION OF THE REPORT The following chapters present results and analysis from the online survey and interviews. Chapter two describes the meth- odology for recruiting airports. Chapter three provides an overview of the findings and examines broad, cross-cutting topics. Understanding Life-Cycle Costs To evaluate the true cost of ownership of vehicles, airport fleet managers should consider estimating the life-cycle cost of ownership, typically in $/mi. This formula incorporates upfront vehicle costs, fuel costs, maintenance and repair costs, infrastructure costs, and vehicle disposal costs. Additionally, the life-cycle costs should capture differences in the training requirements, permitting, or management of the vehicles, if needed. How Important Are Greenhouse Gas Emissions from Fleet Vehicles? At the Philadelphia, Los Angeles, and MinneapolisâSaint Paul International Airports, fleet vehicles account for 38%, 43%, and 45% of Scope 1 emissions, respectively.
9 Chapter four highlights interview results and findings for each of the fuel types. Chapter five discusses user experiences for three vehicle categories. Chapter six concludes this synthesis report with a summary of the study findings and next steps. TABLE 5 TOOLS FOR ALTERNATIVE FUELS IN AIRPORT FLEETS Tool Name Description Emissions Tools URL Greenhouse Gas Regulated Emis- sions and Energy Use in Transporta- tion Model (GREET) This model enables users to easily perform life-cycle analysis simulations of alternative transportation fuels and vehicle technologies. https://greet.es.anl.gov/ Aviation Environmental Design Tool (AEDT) AEDT is a software system that dynamically models aircraft performance in space and time to simulate fuel burn, emis- sions, and noise. https://aedt.faa.gov/ MOtor Vehicle Emission Simulator (MOVES) This emission modeling system estimates emissions for mobile sources at the national, county, and project levels for criteria air pollutants, GHGs, and air toxins. https://www.epa.gov/moves EMission FACtor (EMFAC) This emissions model is developed and used by the California Air Resources Board to assess emissions from on-road vehi- cles including cars, trucks, and buses in California. https://www.arb.ca.gov/msei/categories.htm How Clean Is Your Electric Vehicle? This calculator allows users to compare emissions of plug-in hybrid electric and battery electric vehicles to gasoline-only vehicles, by ZIP code. http://www.ucsusa.org/clean-vehicles/electric- vehicles/ev-emissions-tool#.WJC2aUn2bct Economic Tools Alternative Fuel Life-Cycle Environ- mental and Economic Transportation (AFLEET) Tool This tool helps users examine both the environmental and economic costs and benefits of alternative fuel and advanced vehicles. https://greet.es.anl.gov/afleet Alternative Fuel Price Report The Clean Cities Alternative Fuel Price Report provides regional alternative and conventional fuel prices for bio- diesel, compressed natural gas, ethanol, hydrogen, propane, gasoline, and diesel. http://www.afdc.energy.gov/fuels/prices.html VICE 2.0: Vehicle and Infrastructure Cash-Flow Evaluation (VICE) Model The VICE model version 2.0 is the second generation of the financial model developed by the National Renewable Energy Laboratory for fleet managers, to assess the financial sound- ness of converting their fleets to run on CNG. http://www.afdc.energy.gov/vice_model/ Vehicle Cost Calculator This tool uses basic information about driving habits to calcu- late total cost of ownership and emissions for makes and mod- els of most vehicles, including alternative fuel and advanced technology vehicles. http://www.afdc.energy.gov/calc/ Electric Vehicle (EV) Charging Financial Analysis Tool This tool was developed to evaluate the financial viability of EV charging infrastructure investments involving multiple pri- vate and public sector partners. https://www.c2es.org/publications/ business-models-financially-sustainable-ev- charging-networks Electric Vehicle Explorer This tool enables users to determine whether an EV is right for them by comparing the costs of several vehicles. http://gis.its.ucdavis.edu/evexplorer/#!/ locations/start General Tools Alternative Fueling Station Locator This interactive map enables users to find alternative fueling stations near an address or ZIP code or along a route in the United States. http://www.afdc.energy.gov/locator/stations/ Petroleum Reduction Planning Tool This planning tool helps vehicle fleets reduce petroleum con- sumption and GHG emissions. https://www.afdc.energy.gov/prep/ Database of Federal and State Laws and Incentives This database enables users to search incentives and laws related to alternative fuels and advanced vehicles by jurisdiction. http://www.afdc.energy.gov/laws/search