A hybrid life cycle assessment of public transportation buses with alternative fuel options
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Alternative fuel options are gaining popularity in the vehicle market. Adopting alternative fuel options for public transportation compared to passenger vehicles contributes exponentially to reductions in transportation-related environmental impacts. Therefore, this study aims to present total air pollutant emissions and water withdrawal impacts through the lifetime of a transit bus with different fuel options.
In consideration of market share and future development trends, diesel, biodiesel, compressed natural gas (CNG), liquefied natural gas (LNG), hybrid (diesel-electric), and battery electric (BE) transit buses are analyzed with an input-output (IO)-based hybrid life cycle assessment (LCA) model. In order to accommodate the sensitivity of total impacts to fuel economy, three commonly used driving cycles are considered: Manhattan, Central Business District (CBD), and Orange County Transit Authority (OCTA). Fuel economy for each of these driving cycles varies over the year with other impacts, so a normal distribution of fuel economy is developed with a Monte Carlo simulation model for each driving cycle and corresponding fuel type.
Results and discussion
Impacts from a solar panel (photovoltaic, PV) charging scenario and different grid mix scenarios are evaluated and compared to the nation’s average grid mix impacts from energy generation to accommodate the lifetime electricity needs for the BE transit bus. From these results, it was found that the BE transit bus causes significantly low CO2 emissions than diesel and other alternative fuel options, while some of the driving cycles of the hybrid-powered transit bus cause comparable emissions to BE transit bus. On the other hand, lifetime water withdrawal impacts of the diesel and hybrid options are more feasible compared to other options, since electricity generation and natural gas manufacturing are both heavily dependent on water withdrawal. In addition, the North American Electricity Reliability Corporation’s (NERC) regional electricity grid mix impacts on CO2 emissions and water withdrawal are presented for the BE transit bus.
As an addition of current literature, LCA of alternative fuel options was performed in this paper for transit buses with the consideration of a wide variety of environmental indicators. Although the results indicate that BE and hybrid-powered buses have less environmental emissions, the US’s dependency on fossil fuel for electricity generation continues to yield significant lifetime impacts on BE transit bus operation. With respect to water withdrawal impacts, we believe that the adoption of BE transit buses will be faster and more environmentally feasible for some NREC regions than for others.
KeywordsAlternative fuel-powered transit buses Environmental life cycle assessment Electricity grid mix Monte Carlo simulation Water withdrawal
This material is based upon work supported in part by the Electric Vehicle Transportation Center funded by the US Department of Transportation University Transportation Centers Program.
Compliance with ethical standards
Dr. Omer Tatari and Tolga Ercan declare that they have no conflict of interest. This article does not contain any studies with human or animal subjects.
- Argonne National Laboratory (2013) GREET1 Model 2013. Chicago: U.S. Department of Energy Argonne National Laboratory. Retrieved from https://greet.es.anl.gov/main
- Assessment and Standards Division Office of Transportation and Air Quality U.S. Environmental Protection Agency (2012) Motor Vehicle Emission Simulator (MOVES). Retrieved from http://www.epa.gov/otaq/models/moves/#generalinfo
- BAE Systems (2015) “HybriDrive Propulsion Systems” on the Internet at http://www.hybridrive.com/literature.php [Accessed on August 2014]
- Bailey L, Mokhtarian PL, Little A (2008) The broader connection between public transportation, energy conservation and greenhouse gas reduction. ICF International, TCRP Project J-11/Task 3 Transit Cooperative Research Program, Transportation Research BoardGoogle Scholar
- Barnitt R (2006) Case study: ebus hybrid electric buses and trolleys. Technical report. National Renewable Energy Laboratory, Golden, COGoogle Scholar
- Barnitt R (2008) BAE/Orion hybrid electric buses at New York City transit. A generational comparison. Technical report. National Renewable Energy Laboratory, Golden, COGoogle Scholar
- Callaghan L, Lynch S (2005) Analysis of electric drive technologies for transit applications: battery-electric, hybrid-electric, and fuel cells. Final report. Federal Transit Administration, Washington, DCGoogle Scholar
- Carnegie Mellon University Green Design Institute (2014) Economic Input-Output Life Cycle Assessment (EIO-LCA) US 2002 (428 sectors) Producer model [Internet], Available from: http://www.eiolca.net/ [Accessed 15 July, 2014]
- Clark NN, Zhen F, Wayne WS, Lyons DW (2007) Transit bus life cycle cost and year 2007 emissions estimation. Final report. Federal Transit Administration, Washington DCGoogle Scholar
- Clark NN, Zhen F, Wayne WS, Schiavone JJ, Chambers C, Golub AD, Chandler KL (2009) Assessment of hybrid-electric transit bus technology. Transportation Research Board, Washington, DCGoogle Scholar
- Cooney G, Hawkins TR, Marriott J (2013) Life cycle assessment of diesel and electric public transportation buses. J Ind Ecol 17(5):689–699Google Scholar
- Engholm A, Johansson G, Persson AA (2013) Life cycle assessment of Solelia Greentech’s photovoltaic based charging station for electric vehicles. Technical report. Uppsala Universitet, Uppsala, SwedenGoogle Scholar
- García Sánchez JA, López Martínez JM, Lumbreras Martín J, Flores Holgado MN, Aguilar Morales H (2013) Impact of Spanish electricity mix, over the period 2008–2030, on the life cycle energy consumption and GHG emissions of electric, hybrid diesel-electric, fuel cell hybrid and diesel bus of the Madrid Transportation System. Energy Convers Manag 74:332–343CrossRefGoogle Scholar
- Hendrickson CT, Lave LB, Matthews HS (2006) Environmental life cycle assessment of goods and services: an input-output approach. Resources for the Future, Washington, DCGoogle Scholar
- Hess D (2007) What is a clean bus? Object conflicts in the greening of urban transit. Sustain: Sci Pract Policy 3(1):45–58Google Scholar
- International Standards Organization (2006) ISO 14040-Environmental management-life cycle assessment-principles and framework. http://www.iso.org/iso/catalogue_detail?csnumber=37456. Accessed Aug 2014
- Johnson C (2010) Business case for compressed natural gas in municipal fleets. Technical report. National Renewable Energy Laboratory, Washington, DCGoogle Scholar
- Kawashima T (2014) Electric bus system with rapid charging at every bus stop using renewable energy. Mech Eng J 2(1):13-00085-13-00085Google Scholar
- Kay M, Clark M, Duffy C, Laube M, Lian FS (2011) Bus life cycle cost model for federal land management agencies: user’s guide. Final report. U.S. Department of Transportation Research and Innovative Technology Administration John A. Volpe National Transportation Systems Center, CambridgeGoogle Scholar
- Larrousse PJ, Aoyagi G, Bailly JP, Barker JB, Barnes LEE, Barnes RL, Blair GL, Freeland RL, Gambaccini LJ, Hunter-zaworski K, Lerner-lam Eva, Monroe Don S (2000) TCRP report 59 hybrid-electric transit buses: status, issues, and benefits. Technical report. Transit Cooperative Research Program by Federal Transit Administration, Washington, DCGoogle Scholar
- Laver R, Schneck D, Skorupski D, Brady S, Cham L, Booz Allen Hamilton (2007) Useful life of transit buses and vans. Final report. Federal Transit Administration, Washington, DCGoogle Scholar
- M.J. Bradley & Associates LLC (2013) Comparison of modern CNG, diesel and diesel hybrid-electric transit buses : efficiency & environmental performanceGoogle Scholar
- Natural Gas Vehicles for America (2014) https://www.ngvamerica.org/stations/cng-station-construction-and-economics/ Accessed on August 2014
- Neff J, Dickens M (2013) 2013 Public transportation fact book. Annual Report (64th Edition). American Public Transportation Association, Washington, DC, pp 1–66Google Scholar
- New Flyer Industries Inc (2014) http://www.bloomberg.com/news/2013-09-13/new-flyer-ceo-sees-growth-as-u-s-buses-age.html (Sep, 2013). Accessed on July 2014
- Peschiera B, Williamson SS (2013) Review and comparison of inductive charging power electronic converter topologies for electric and plug-in hybrid electric vehicles. In Transportation Electrification Conference and Expo (ITEC), 2013 IEEE. IEEE, Detroit, pp 1–6Google Scholar
- Richardson S (2013) Hybrid-diesel vs. CNG: an updated comparison of transit fleet alternatives. Technical report. Public Solutions Group LtdGoogle Scholar
- Samaras C (2008) A life-cycle approach to technology, infrastructure, and climate policy decision making: transitioning to plug-in hybrid electric vehicles and low-carbon electricity. Doctoral Dissertation, retrieved from ProQuest Dissertations and ThesesGoogle Scholar
- Tesla Motors Inc. (2014) Tesla Motors Inc. 2020 Gigafactory. http://www.teslamotors.com/gigafactory. Accessed June 2014
- Transportation Research Board National Research Council (1993) Safe operating procedures for alternative fuel buses a synthesis of transit practice. Technical report. Transit Cooperative Research Program, Washington, DCGoogle Scholar
- Traut E, Hendrickson C, Klampfl E, Liu Y, Michalek JJ (2011) Optimal design and allocation of electrified vehicles and dedicated charging infrastructure for minimum greenhouse gas emissions. In 90th Annual Meeting of the Transportation Research Board, Washington, DCGoogle Scholar
- U.S. Bureau of Labor Statistics (2015a) Consumer price index database on the internet. At http://www.bls.gov/cpi/#data [Retrieved on September 2014]
- U.S. Bureau of Labor Statistics (2015b) Producer price index database on the internet. At http://www.bls.gov/ppi/#data [Retrieved on September 2014]
- U.S. Department of Energy (2013) Clean cities alternative fuel price report. U.S. Department of Energy, @@Washington DC, pp 1–17Google Scholar
- U.S. Energy Information Administration (2013) Annual energy outlook 2013 with projection to 2040. Final report. U.S. Energy Information Administration Office of Integrated and International Energy Analysis, U.S. Department of Energy, Washington, DCGoogle Scholar
- U.S. Environmental Protection Agency (2014) Inventory of U.S. greenhouse gas emissions and sinks: 1990–2012. Final report. U.S. Environmental Protection Agency, Washington, DCGoogle Scholar
- Wu M, Peng MJ (2011) Developing a tool to estimate water use in electric power generation in the United States. Argonne National Laboratory, https://greet.es.anl.gov/publication-watertool
- Wu HH, Gilchrist A, Sealy K, Israelsen P, Muhs J (2011) A review on inductive charging for electric vehicles. 2011 I.E. Int Electr Mach Drivers Conf (IEMDC), IEEE, pp 143–147Google Scholar