Energy Savings Strategies for Transit Agencies (2013)

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5 The types of fuels that transit vehicles use shape the opportunities for energy conservation. The U.S. transit fleet is powered by a combination of diesel fuel, electricity, natural gas, and gasoline, as shown Table 2, with each service mode using a different mix of fuels. Generally speaking, ferries and buses primarily use diesel fuel or gasoline, whereas most rail systems are powered by electricity. Together these fuel types account for 81% of the total energy consumed by transit. Compressed natural gas (CNG) accounts for another 12%. MEASURING ENERGY USE IN VEHICLES Transit agencies can measure energy used in transit vehicles in several ways. Typically, transit agencies measure energy in terms of the amount of fuel or electricity consumed by vehi- cles. Fuel and electricity consumption represent operational or pump-to-wheel energy use. A certain amount of additional energy, commonly called well-to-pump or upstream energy, is also required to extract, refine, and transport fuel used in vehi- cles or at power plants. Well-to-wheel energy consumption combines both well-to-pump and pump-to-wheel energy use. Although well-to-wheel energy consumption is not routinely measured, it is an important factor when considering some types of energy-saving strategies for transit agencies. For example, switching from diesel fuel to biodiesel has impacts on well-to-wheel energy consumption that will be of inter- est to transit agencies considering their total environmental impacts. This synthesis generally discusses simple fuel con- sumption or pump-to-wheel energy use; however, well-to- wheel impacts are referenced where data are available. Transit agencies can also measure energy use in several types of units. Liquid fuels, including gasoline and diesel, are measured in gallons. Electricity is measured in kilowatt-hours (kWh). CNG is sometimes measured in cubic feet. However, using these units can make it difficult to compare energy use between transportation modes that use different fuel types. Therefore, it is useful to convert fuel consumption to standard units such as British Thermal Units (BTUs) or Gasoline Gallon Equivalents. Table 3 shows the conversion factors between var- ious fuel measurement units and both BTUs and Gasoline Gal- lon Equivalents. Although this synthesis makes an effort to use common units for energy use wherever possible, it is important that transit agencies be conversant in all types of units. When tracking and reporting energy use, agencies some- times track both total energy use and energy use normalized per Transit agencies in the United States operate hundreds of thousands of vehicles, as well as thousands of transit sta- tions and maintenance facilities, in order to take millions of passengers to their destinations each day. This is an energy- intensive undertaking every step of the way. As a result, tran- sit agencies have many opportunities to reduce their energy use or to increase their energy efficiency. They also have many incentives to do so. Reducing energy use saves money, reduces environmental impacts, and improves energy security for transit agencies. Promoting energy savings can also help transit agencies improve the public’s opinion of their services. This chapter explores how transit agencies use energy for different purposes and discusses crucial concepts in transit energy use and energy savings. ENERGY USED FOR VEHICLE PROPULSION The vast majority of the energy that transit agencies consume is used to move vehicles. Figure 2 details the sources of GHG emissions produced by the New York Metropolitan Trans- portation Authority (NYMTA). Because GHG emissions are highly correlated with energy use, the chart is a reasonable proxy for the amount of NYMTA’s total energy use attributed to the use of vehicles (traction) and facilities (non-traction). In total, 79% of the GHG emissions produced—and a similar share of the energy consumed—is attributed to transit vehicles. Although similar statistics are not widely available for other transit agencies, the proportion of total energy used for propul- sion may well be higher for other transit systems. Smaller agen- cies do not have as many non-traction energy users, including bus and rail stations, which consume energy for lighting, equip- ment, and climate control. Energy purchases are also a significant item in transit agencies’ budgets. For example, the Los Angeles Metropoli- tan Transportation Authority (LA Metro) spends $21 million annually (almost 2% of the agency’s operating budget) on electricity to power rail lines (3). The agency spends a simi- lar amount each year to fuel its buses (4). For all of its tran- sit railcar propulsion needs, NYMTA spends approximately $237 million annually (about 3% of its operating budget) on electricity (5). Although these energy expenditures do not represent a large proportion of these agencies’ total operat- ing budgets, they nonetheless suggest opportunities to save millions of dollars a year through energy conservation. chapter two ENERGY USE AT TRANSIT AGENCIES

6 boarding or per vehicle-revenue-mile. Normalizing energy use is particularly helpful for agencies that are expanding the ser- vice that they provide. Although total fuel use will increase for such agencies, fuel use per vehicle-revenue-mile may decrease. The latter indicates an improvement in average vehicle fuel efficiency. ENERGY USED IN FACILITIES In addition to the energy required for vehicle propulsion, transit agencies use energy to power their buildings and other structures, including administrative offices, maintenance facilities and garages to store and repair vehicles, and sta- tions or stops along transit routes, which range from bus shel- ters to large multimodal transit hubs. Some of these facilities use energy for transit-specific purposes, such as bus repair or maintenance, whereas other facilities use energy for generic purposes such as powering lights, computers, and appliances; heating water; and maintaining the temperature. Energy used in facilities is typically electricity, natural gas, or fuel oil for heating. In an average commercial building the largest portion of energy goes to heating, with significant percentages used for lighting and “other,” which includes service equipment and combined heat and power (8). Figure 3 shows the distribu- tion of energy use in U.S. commercial buildings. The figure provides a reasonable estimate for the breakdown of energy use in transit agencies’ administrative buildings. Other types of facilities, such as maintenance facilities and transit stations, also use energy for transit-specific purposes. COMPARING TRANSIT WITH OTHER TRANSPORTATION MODES Although transit agencies use a significant amount of energy, they also help reduce the overall amount of energy used in the entire transportation system. Public transit vehicles, when efficiently used, are more energy efficient than per- sonal automobiles on a per passenger mile basis. The total amount of energy that a region uses for transportation can therefore be reduced if travelers shift from personal vehicles to public transit. The number of people traveling in each vehicle often determines whether transit is reducing more energy than it consumes. The average fuel economy of a new passenger car is nearly 24 miles per gallon (mpg); therefore, the typical bus, which gets less than five mpg, needs to carry at least six passengers in order to be more energy-efficient on a per passenger mile basis than a single-occupant vehicle FIGURE 2 New York Metropolitan Transportation Authority greenhouse gas emissions. [Greening Mass Transit & Metro Regions (2)]. Mode Electricity Share of Total Energy Consumed in BTUs Diesel fuel Gasoline LNG and blends CNG and blends Biodiesel Other Total Bus 0% 68% 1% 4% 21% 6% 1% 100% Commuter Rail 33% 66% 0% 0% 0% 0% 1% 100% Heavy Rail 100% 0% 0% 0% 0% 0% 0% 100% Light Rail 95% 5% 0% 0% 0% 0% 0% 100% Paratransit 0% 39% 54% 0% 2% 4% 1% 100% Trolley Bus 100% 0% 0% 0% 0% 0% 0% 100% Other 3% 69% 28% 0% 0% 0% 0% 100% All Modes 15% 56% 10% 2% 12% 4% 1% 100% Adapted from 2011 Public Transportation Fact Book (6). CNG = compressed natural gas; LNG = liquefied natural gas. TABLE 2 CATEGORIES OF ENERGY SAVING STRATEGIES AND EXAMPLE

7 (9, 10). Meanwhile, a bus filled to capacity uses less fuel per passenger mile than a personal car with four passengers (9). Although transit agencies can reduce energy use by imple- menting energy-efficient vehicle technologies, improving service to attract new riders or consolidating service to elimi- nate wasteful routes can also increase energy efficiency sub- stantially on a per passenger basis. Transit also helps to reduce congestion, which in turn reduces energy use, because vehicles operate more efficiently in free-flowing conditions. Finally, transit service may encour- age more compact development patterns, which reduces aver- age trip lengths and can make alternative modes such as biking or walking more appealing. Collectively known as displaced energy use, these effects are considered all-important when conducting a comprehen- sive assessment of transit’s impacts on energy use. However, several other research papers have explored the impacts of transit on mode shift, congestion, and compact development. This report focuses on the actions that transit agencies are taking to reduce their own energy consumption. Fuel Type Unit of Measure BTU/Unit Gasoline Gallon Equivalent (GGE) Gasoline (regular) gallon 114,100 1.00 gallon Diesel #2 gallon 129,500 0.88 gallon Biodiesel (B100) gallon 118,300 0.96 gallon Biodiesel (B20) gallon 127,250 0.90 gallon Compressed Natural Gas (CNG) cubic foot 900 126.67 cu. ft. Liquid Natural Gas (LNG) gallon 75,000 1.52 gallon Propane (LPG) gallon 84,300 1.35 gallon Ethanol (E100) gallon 76,100 1.50 gallon Ethanol (E85) gallon 81,800 1.39 gallon Methanol (M100) gallon 56,800 2.01 gallon Methanol (M85) gallon 65,400 1.74 gallon Electricity kilowatt hour (kWh) 3,400 33.56 kWh “Gasoline Gallon Equivalent Definition” (7) [Online]. Available: https://www.afdc.energy.gov/afdc/prep/popups/gges.html [accessed May 7, 2012]. TABLE 3 CONVERSION FACTORS AND ENERGY INTENSITY BY FUEL TYPE Lighting 20% Space Heating 16% Space Cooling 15% Ventilation 9% Refrigeration 7% Water Heating 4% Electronics 4% Computers 4% Cooking 1% Other (5) 15% Unattributed 5% FIGURE 3 Energy use in commercial buildings (BTUs) 2010. (Adapted from “3.1.4—Commercial Sector Energy Consumption,” Buildings Energy Data Book (8) [Online]. Available: http://buildingsdatabook.eren.doe.gov/default.aspx.