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Proterra EcoRide

Proterra EcoRide BE35
EcoRide BE35 in service with Foothill Transit
Overview
ManufacturerProterra
Production2010–2014
Body and chassis
ClassTransit bus
LayoutRear-engine, rear-wheel-drive
Powertrain
Electric motorUQM Technologies PP220[1][2]
Transmission
Dimensions
Wheelbase236 to 237 in (5.99 to 6.02 m)[1][2]
Length35 ft 8+1⁄2 in (10.9 m)[1][2]
Width101.4 to 103 in (2.58 to 2.62 m)[1][2]
Height132 to 134 in (3.35 to 3.40 m)[1][2]
Curb weight27,680 to 28,180 lb (12,600 to 12,800 kg)[1][2]
Chronology
SuccessorProterra Catalyst

The Proterra EcoRide BE35 is a 35 foot (11 m) (nominal length) fast-charge battery electric bus that seats 38 (including the driver) with a total passenger capacity of 60 in its composite low floor body. Foothill Transit was the first transit agency to operate the buses in revenue service, starting in September 2010.[3][4] It is the first 30 ft (9 m) or larger, heavy-duty all-electric bus ever to complete federally required durability, reliability and safety testing at the Bus Research and Testing Center in Altoona, Pennsylvania. The 12yr/500,000 miles (800,000 km) STURAA test was completed on March 5, 2012.[1]

The BE35's electric traction motor draws from lithium-titanate batteries supplied by Altairnano that can be recharged in 5–10 minutes while stopped at a bus stop via overhead terminals connected to a charging station, without driver involvement.[5] The quick charging during a brief layover typically enables a further 26 miles (42 km) of operation.[6][7]

History

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TransTeq EcoMark I for 16th Street Mall service

CEO Dale Hill and VP Phil Sweesy of Mobile Energy Solutions, LLC (MES) in Golden, Colorado had previously designed, engineered, and manufactured the 36 CNG-fueled TransTeq EcoMark I hybrid buses for the 16th Street Mall in Denver, Colorado.[8][9][10][11] In 2006, MES announced it was designing a battery-electric bus codenamed "Origin One", recharged by onboard hydrogen fuel cells; the company announced it had already won a contract for two buses from the Greater New Haven Transit District, the transit agency serving New Haven, Connecticut.[12] This was followed by a 2007 contract for two more fuel cell buses for Burbank, California; by this time the key characteristics were announced: a 35-foot (11 m) composite body provided by Martin Marietta, lithium-titanate batteries, and plug-in charging in addition to onboard charging through the use of a range-extending auxiliary power unit (APU) consisting of two 16 kW fuel cells from Hydrogenics.[13]

Developmental funding was provided by the Federal Transit Administration (FTA), who had awarded a grant under the National Fuel Cell Bus Program to a team led by the Center for Transportation and the Environment (CTE); CTE had selected MES to develop the prototype bus.[14] MES was also a partner in the FTA's Electric Drive Strategic Plan program.[15] MES acquired an old school bus to serve as a mobile development laboratory (MDL) for drivetrain development, including the battery, traction motor, and control system. The MDL was damaged after one battery cell leaked electrolyte, short-circuited, and caught on fire, leading MES to redesign its battery management system and add a protective enclosure for the battery modules in the finished prototype.[16]: 15 

MES changed its name to Proterra in June 2008[17] and exhibited a prototype of the HFC35 transit bus that October at the American Public Transit Association Expo in San Diego.[18]: 34  As shown with the fuel cell APU, Proterra claimed the HFC35 had a range of 250 miles (400 km) before needing to be refueled or recharged.[15] Alternatively, the HFC35 could be optioned with diesel, gasoline, or natural gas APUs.[19]

In 2009, Proterra demonstrated a variant of the HFC35 that omitted the APU altogether,[20] which Proterra named the EcoRide BE35.[21] The BE35 stopped in four California cities during its weeklong tour: San Jose, Los Angeles, Sacramento, and San Francisco.[22][23]

Deployment

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TARC EcoRide BE35, docked in overhead charger (2015)

The HFC35 prototype exhibited at APTA '08 in San Diego[24] was later demonstrated in Washington, D.C. (Nov 2008)[5] and a nationwide tour in regular service was scheduled for 2009, starting in Columbia, South Carolina[15] as a football stadium shuttle for the University of South Carolina (with maintenance, refueling, and charging at Central Midlands Regional Transit Authority), with Capital Metro in Austin, Texas,[25] and at the 2010 Olympic and Paralympic Winter Games in Vancouver, British Columbia.[16]: 4, 18  A second HFC35 was ordered by the City of Burbank, and a third was ordered by the United States Department of Defense (DoD) for use in Washington state.[16]: 13  Burbank's HFC35 entered service in May 2010.[26] The DoD HFC35 was delivered to Joint Base Lewis–McChord in Tacoma, Washington,[27] where it was powered by hydrogen reformed from mewthane produced during wastewater treatment.[28][29]

The first production BE35 was delivered to Foothill Transit in September 2010, operating as the "EcoLiner" on line 291 between Pomona and La Verne.[4] Other agencies that purchased BE35 buses and charging equipment included the Nashville Metropolitan Transit Authority,[30] Worcester Regional Transit Authority,[31] San Joaquin Regional Transit District (Stockton),[32] VIA Metropolitan Transit (San Antonio),[33][34] StarMetro (Tallahassee),[35][36] Regional Transportation Commission of Washoe County (Reno), and Clemson Area Transit (Seneca, South Carolina);[37] most purchases were funded by more than $25 million in grants from the FTA's Transit Investments for Greenhouse Gas and Energy Reduction (TIGGER) program.[38]

Proterra introduced the 40-foot (12 m) Catalyst in 2014, featuring a longer range and new fast-charging system.[39]

Design

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Proterra drew inspiration from existing and prototype composite buses: the Neoplan USA Metroliner in Carbon [de], Advanced Technology Transit Bus (ATTB), and NABI CompoBus, concluding that a composite bus body was best suited to reduce weight and accommodate an equivalent number of seats (37) as a conventional 40-foot (12 m) low-floor transit bus. The composite body forms were finished by Pearson Composites in Warren, Rhode Island, and the shells were assembled by C&C Fiberglass Components using vacuum-assisted resin transfer molding.[14] Some of the people who helped develop ATTB would go on to work for MES.[15]

Although the batteries can be recharged quickly, the overall capacity is low. The BE35 and HFC35 shared the same electric powertrain and battery design;[16] while the HFC35 had a range-extending APU, no additional battery storage capacity was added to the BE35. The battery pack has a total storage capacity of 54 to 72 kW-hr,[40] composed of three or four 18 kW-hr battery strings. Each string weighs 550 pounds (250 kg).[41] A single string is built from sixteen modules wired in series, each rated at 50 A-hr and 23 volts; the total string is 368 volts and 18.4 kW-hr, and three or four strings are used in parallel for the overall capacity of 54 or 72 kW-hr.[42]: 12  However, using on-route fast charging, an EcoRide BE35 set a record in April 2014 by driving more than 700 miles (1,100 km) in 24 hours.[43][44] In June 2016, Proterra announced it would grant royalty-free access to the patents covering their FastFill overhead charging system.[45]

Proterra uses the TerraVolt branding for the battery system and ProDrive for the drivetrain module, which includes the traction motor and optional range-extending APU.[46][47] The traction motor announced with the HFC35 and the first versions of the EcoRide BE35 was supplied by UQM Technologies and branded PowerPhase 150,[19] offering a peak and continuous power output of 150 and 100 kW (200 and 130 hp), and peak and continuous torque of 650 and 400 N⋅m (480 and 300 ft⋅lb), respectively.[48] The traction motor was upgraded to the UQM PowerPhase HD220 in 2013, which increases peak power and torque to 220 kW (300 hp) and 700 N⋅m (520 ft⋅lb), respectively.[49]

Testing

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The first HFC35 prototype was not available for service for approximately two months to address a failure in a DC-DC converter, which provided the interface between the fuel cell APU and the traction battery.[16]: 21 

Results from the BE35 STURAA test showed an average, combined fuel economy of 1.81 kWh/mi (1.12 kW⋅h/km) or 20.84 miles per US gallon (11.29 L/100 km) diesel equivalent.[2]: 39  Compared to the buses it replaces—conventional diesel buses average 3.86 miles per US gallon (60.9 L/100 km); CNG buses return 3.27 miles per US gallon (72 L/100 km) diesel equivalent; and diesel-hybrid buses average about 4.6 miles per US gallon (51 L/100 km)[50]—the results are up to 600% better. During 15,000 miles (24,000 km) of testing at Altoona for the first BE35, unscheduled maintenance included the replacement of the transmission (twice) and the traction motor (once).[1]: 86–90 

Foothill Transit EcoRide BE35, line 291 (2016)

Foothill Transit has been working with the California Air Resources Board and the United States Department of Energy National Renewable Energy Laboratory (NREL) to study the real-world performance of its Proterra buses.[51][52][53] Observed economy for twelve BE35 buses in the Foothill Transit fleet was 17.24 miles per US gallon (13.64 L/100 km) diesel equivalent, compared to an observed 4.15 miles per US gallon (56.7 L/100 km) diesel equivalent for a fleet of eight NABI 42-BRT CNG-fueled buses. However, the BE35 fleet operates on circulator routes at slower speeds compared to the NABI CNG fleet, which were dispatched as needed to any Foothill Transit route. The BE35 fleet achieved an availability of 80.6%, less than the desired 85% availability due to constraints on parts availability and low-voltage battery (i.e., not the propulsion batteries) reliability; the NABI CNG fleet achieved an availability of 96.8%. Total maintenance costs for the BE35 fleet ($0.41/mi) is also higher than the maintenance cost for the NABI CNG fleet ($0.27/mi).[53]

References

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  1. ^ a b c d e f g h i STURAA Test: 12 Year, 500,000 mile bus from Proterra, Inc. | Model BE-35 (Report). Pennsylvania Transportation Institute. April 2012.
  2. ^ a b c d e f g h STURAA Test: 12 Year, 500,000 mile bus from Proterra, Inc. | Model BE-35 (Report). Pennsylvania Transportation Institute. May 2013.
  3. ^ "L.A. Gets World's First Rapid-Charge Electric Bus". TechChunks. US. September 20, 2010. Retrieved April 18, 2016.
  4. ^ a b Barry, Keith (September 13, 2010). "Quick-charge electric bus rolls into L.A. County". Wired. Retrieved July 12, 2018.
  5. ^ a b Barry, Keith (November 4, 2009). "Altairnano batteries make Proterra a magic bus". Wired. Retrieved July 12, 2018.
  6. ^ "California City First To Get 2nd-Generation Proterra Electric Bus".
  7. ^ "Electric bus manufacturers BYD and Proterra are making serious moves". 22 July 2014.
  8. ^ "Proterra In The News: Innovative Hydrogen Transportation Project Unveiled in New Haven, Connecticut" (Press release). Proterra Online. September 1, 2005. Archived from the original on October 19, 2008.
  9. ^ Franklin, Rod (August 26, 2002). "Buses combine natural gas with electrical system". Boston Business Journal. Retrieved 12 November 2020.
  10. ^ "FTA Awards $5.67 Million to Demonstrate Economical Hybrid-Electric Fuel Cell Bus" (Press release). Proterra. October 13, 2006. Archived from the original on October 19, 2008.
  11. ^ Lawson, Pamela (December 8, 2005). "Proterra In The News: A clean getaway: Changing transportation with hybrids". Proterra Online. Archived from the original on October 19, 2008.
  12. ^ "Proterra In The News: Colorado Company Building New Energy-Efficient Bus" (Press release). Proterra Online. February 21, 2006. Archived from the original on October 19, 2008.
  13. ^ "Proterra In The News: Burbank Zero Emission Bus Project Fist of its Kind West of the Mississippi" (Press release). Proterra Online. August 15, 2007. Archived from the original on October 19, 2008.
  14. ^ a b Winkel, John (May 17, 2009). "Team-built bus body bests all". Composites World. Retrieved 12 November 2020.
  15. ^ a b c d Hubbard, David (January 1, 2009). "Efficiency grows from the ground up". Bus Ride. Retrieved 13 November 2020.
  16. ^ a b c d e Eudy, Leslie; Chandler, Kevin (October 2011). National Fuel Cell Bus Program: Proterra Fuel Cell Hybrid Bus Report, Columbia Demonstration (PDF) (Report). Federal Transit Administration. Retrieved 13 November 2020.
  17. ^ "Mobile Energy Solutions, LLC changes name to Proterra" (Press release). Proterra. June 24, 2008. Archived from the original on October 19, 2008.
  18. ^ Starcic, Janna; Roman, Alex; Schlosser, Nicole (November–December 2008). "Transportation's Green Future on Display at APTA EXPO" (PDF). Metro Magazine. pp. 20–50. Archived from the original (PDF) on December 29, 2009.
  19. ^ a b "Proterra LLC Introduces HFC35 Alternative-Fuel Transit Bus" (Press release). Proterra. June 24, 2008. Archived from the original on October 19, 2008.
  20. ^ Gage, Deborah (February 7, 2009). "Battery-powered bus offers a quiet ride". San Francisco Chronicle. Retrieved 12 November 2020.
  21. ^ Kanellos, Michael (February 6, 2009). "Too Much! The Electric Bus!". Greentech Media. Retrieved 12 November 2020.
  22. ^ "Proterra's zero emission bus tours California". busworld. February 10, 2009. Retrieved 13 November 2020.
  23. ^ Barz, Sara (February 14, 2009). "A zero-emission bus tours California, Toyota flirts with ethanol, and more green auto news". grist. Retrieved 13 November 2020.
  24. ^ "Proterra unveils HFC35 hybrid transit bus". Fuel Cells Bulletin. 2008 (12): 2. December 2008. doi:10.1016/S1464-2859(08)70429-2.
  25. ^ "Proterra Prototype Fuel Cell Hybrid Bus". Center for Transportation and the Environment. 13 December 2013. Retrieved 13 November 2020.
  26. ^ Cadelago, Christopher (May 1, 2010). "Burbank gets first plug-in fuel cell bus". Burbank Leader. Retrieved 13 November 2020.
  27. ^ "Fort Lewis Hydrogen Fuel Cell Pilot Program". Center for Transportation and the Environment. 14 July 2013. Retrieved 13 November 2020.
  28. ^ "Hydrogen from waste in US military FCVs". Fuel Cells Bulletin. 2012 (3): 1. March 2012. doi:10.1016/S1464-2859(12)70059-7.
  29. ^ "Proterra Fuel Cell Hybrid Bus in DoD Hydrogen Energy Cycle Pilot Project". Green Car Congress. July 11, 2009. Retrieved 13 November 2020.
  30. ^ "Nashville MTA Orders More Proterra EcoRide Electric Buses". Next-Gen Transportation News. September 15, 2015. Retrieved 13 November 2020.
  31. ^ "Proterra to Provide Three EcoRide Zero-Emission Battery-Electric Transit Buses to WRTA" (Press release). Mass Transit (magazine). September 26, 2012. Retrieved 13 November 2020.
  32. ^ Loveday, Eric (May 27, 2013). "Pair of Rapid-Charge Electric Proterra EcoRide B35 Buses Enter Service in California". Inside EVs. Retrieved 13 November 2020.
  33. ^ Rivard, Robert (June 25, 2015). "Electric Trolley Pays a Quiet Visit to San Antonio". San Antonio Report. Retrieved 13 November 2020.
  34. ^ "VIA adds three EcoRides to fleet". BusRide. April 1, 2013. Retrieved 13 November 2020.
  35. ^ "StarMetro Showcases Zero Emission Bus". Center for Transportation and the Environment. November 2012. Retrieved 13 November 2020.
  36. ^ "Proterra to deliver 3 electric transit buses and charging station to StarMetro in Florida". Green Car Congress. October 4, 2011. Retrieved 13 November 2020.
  37. ^ "All-electric transit has arrived". BusRide. August 1, 2013. Retrieved 13 November 2020.
  38. ^ "Proterra to supply 5 transit systems with electric buses". Metro Magazine. November 10, 2010. Retrieved 13 November 2020.
  39. ^ Brophy, Jim (April 29, 2017). "Bus Stop Classics: Proterra All-Electric Urban Transit Bus – The Clean and Quiet Shape of Things to Come". Curbside Classic. Retrieved 13 November 2020.
  40. ^ "GM Ventures Invests in Battery Electric Bus Company" (Press release). General Motors Corporate Newsroom. June 13, 2011. Retrieved 13 November 2020.
  41. ^ "Who killed the electric bus?" (PDF). Theo Fruendt. Retrieved 13 November 2020.
  42. ^ Brecher, Aviva (December 2012). Transit Bus Applications of Lithium Ion Batteries: Progress and Prospects (PDF) (Report). Federal Transit Administration. Retrieved 13 November 2020.
  43. ^ Rosen, Len (May 25, 2014). "Proterra's Electric Bus Travels Over 1,100 Kilometers in 24 Hours". 21st Century Tech Blog. Retrieved 13 November 2020.
  44. ^ Kane, Mark (May 4, 2014). "Proterra Sets Record for Most Miles Traveled in a Day by a Battery-Electric Transit Bus". Inside EVs. Retrieved 13 November 2020.
  45. ^ "Proterra Opens Its Electric Vehicle Fast-Charging Technology to Mass Transit Industry" (Press release). Proterra. June 28, 2016. Retrieved August 4, 2016.
  46. ^ "TerraVolt Energy Storage Systems". Proterra. Archived from the original on September 7, 2011.
  47. ^ "All-Electric ProDrive System". Proterra. Archived from the original on September 7, 2011.
  48. ^ "Proterra EcoRide Battery-Electric Transit Bus Uses UQM PowerPhase 150 System". Green Car Congress. February 9, 2009. Retrieved 12 November 2020.
  49. ^ "UQM Electric-Drive Platform Will Be Built Into Proterra Buses". Next-Gen Transportation News. March 13, 2013. Retrieved 13 November 2020.
  50. ^ Argonne GREET model 2012, assuming 36,000 miles (58,000 km) per year and fuel consumption of 3.86 miles per US gallon (60.9 L/100 km) diesel and 3.27 miles per US gallon (72 L/100 km) diesel equivalent for CNG.
  51. ^ Eudy, Leslie; Prohaska, Robert; Kelly, Kenneth; Post, Matthew (January 2016). Foothill Transit Battery Electric Bus Demonstration Results (PDF) (Report). National Renewable Energy Laboratory. Retrieved July 13, 2018.
  52. ^ Eudy, Leslie; Jeffers, Matthew (June 2017). Foothill Transit Battery Electric Bus Demonstration Results: Second Report (PDF) (Report). National Renewable Energy Laboratory. Retrieved July 13, 2018.
  53. ^ a b Eudy, Leslie; Jeffers, Matthew (May 2018). Foothill Transit Battery Electric Bus Progress Report (PDF) (Report). National Renewable Energy Laboratory. Retrieved July 13, 2018.
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