Proterra Catalyst

The Proterra Catalyst is a battery-electric low-floor transit bus that was built by Proterra from 2014 to 2020. The second generation of Proterra's battery-electric buses, it succeeded the earlier EcoRide as the company's flagship product.

Proterra Catalyst
Top: Catalyst BE40 operated by King County Metro Bottom: Catalyst BE35 operated by San Diego International Airport
Overview
Manufacturer	Proterra
Production	2014–2020
Body and chassis
Class	Transit bus
Layout	Rear-engine, rear-wheel-drive
Powertrain
Electric motor	UQM Technologies PP220 (original)[1] UQM Technologies SPM250-130-2 (ProDrive)[2] 2×Parker Hannifin GVM310-125 (DuoPower)[3]
Transmission	Eaton EEV-7202[1]
Dimensions
Wheelbase	BE40: 296.5 in (7.53 m)[1] BE35: 243 in (6.17 m)[4]
Length	BE40: 42 ft 7+1⁄2 in (12.99 m)[1] BE35: 36 ft 11+1⁄2 in (11.3 m)[4]
Width	102 in (2.59 m)[1]
Height	134 in (3.40 m)[1]
Curb weight	BE40: 27,370 lb (12,400 kg)[1] BE35: 29,910 lb (13,600 kg)[4]
Chronology
Predecessor	Proterra EcoRide
Successor	Proterra ZX5

History

In 2014 Proterra introduced the Catalyst, a fast-charge 100% electric bus to replace the EcoRide BE35. The bus was built on the EcoRide's design and engineering and delivered a longer, lighter and more fuel-efficient bus. The second-generation bus measures either 42 ft (12.8 m) or 36 ft (11.0 m) and weighs approximately 27,000 lb (12,000 kg). The bus is built from lightweight, durable carbon composite. The overall lower weight helps reduce wear and tear on streets. It has no tailpipe and runs virtually silent.

Specifications

With the on-route fast charging system, the Catalyst can be operated continuously, 24/7, without the need to head to the depot for lengthy charge times. Catalyst buses equipped with the Fast Charge (FC) battery pack can charge at a rate of up to 500 kW.^[5] The company added a 35 ft (10.7 m) model of the Catalyst to its product line in October 2015.

Catalyst is a modular system, offered with two different lengths, two different drivetrains, and seven different batteries, depending on the required passenger capacity, speed (hill performance),^[6] and range, respectively.^[7]

Proterra Catalyst combinations^[7]

		Drivetrain
		DuoPower		ProDrive
Output[a]		Peak	Continuous	Peak	Continuous
		240–510 hp 180–380 kW	150–257 hp 112–192 kW	245–295 hp 183–220 kW	150–181 hp 112–135 kW
		MPGe	Range	MPGe	Range
Battery	FC (94 kW-hr)	26.8–27.1 mpg‑US 8.8–8.7 L/100 km	67–68 mi 108–109 km	22.0 mpg‑US 10.7 L/100 km	55 mi 89 km
	FC+ (126 kW-hr)	25.8–26.1 mpg‑US 9.1–9.0 L/100 km	86–94 mi 138–151 km	21.5 mpg‑US 10.9 L/100 km	72 mi 116 km
	XR (220 kW-hr)	27.9–28.1 mpg‑US 8.4–8.4 L/100 km	163–164 mi 262–264 km	23.3 mpg‑US 10.1 L/100 km	136 mi 219 km
	XR+ (330 kW-hr)	26.8–27.1 mpg‑US 8.8–8.7 L/100 km	235–238 mi 378–383 km	22.0 mpg‑US 10.7 L/100 km	193 mi 311 km
	E2 (440 kW-hr)	25.8–26.1 mpg‑US 9.1–9.0 L/100 km	302–305 mi 486–491 km	21.5 mpg‑US 10.9 L/100 km	251 mi 404 km
	E2+[b] (550 kW-hr)	25.2 mpg‑US 9.3 L/100 km	367 mi 591 km	20.7 mpg‑US 11.4 L/100 km	303 mi 488 km
	E2 max[b] (660 kW-hr)	24.3 mpg‑US 9.7 L/100 km	426 mi 686 km	20.0 mpg‑US 11.8 L/100 km	350 mi 560 km
Notes Output depends on battery type. This battery not offered for the 35-foot Catalyst

Drivetrains

At introduction, the Catalyst was equipped with a single electric traction motor, the UQM Technologies HD220.^[1][8] The HD220 was rated at 220 kW (300 hp) peak power (120 kW (160 hp) continuous) and 700 N⋅m (520 ft⋅lb) peak torque (350 N⋅m (260 ft⋅lb) continuous); a later revision, designated HD220+, increased continuous power and torque ratings to 150 kW (200 hp) and 440 N⋅m (320 ft⋅lb), respectively.^[9]

The DuoPower drivetrain was introduced in October 2017; it uses two electric traction motors and has a claimed 20% increase in efficiency compared to the original single-motor drivetrain, which was redesignated ProDrive.^[10] As ProDrive, the Catalyst was equipped with an upgraded UQM HD250 motor,^[2] which offered increased ratings of 250 kW (340 hp) peak power (150 kW (200 hp) continuous) and 900 N⋅m (660 ft⋅lb) peak torque (360 N⋅m (270 ft⋅lb) continuous).^[9] The DuoPower traction motors are permanent magnet alternating current motors^[11] manufactured by Parker Hannifin as part of their Global Vehicle Motor (GVM) series.^[3][12]

Batteries

Buses equipped with the FC (Fast Charge) family of batteries are intended for circulator routes; XR (eXtended Range) battery buses are intended for intermediate-mileage routes; and E2 (Efficient Energy) battery buses are intended for high-mileage routes.^[13] The buses were initially offered with lithium-titanate battery chemistry, which Proterra redesignated the TerraVolt FC. FC batteries can be fully recharged in less than ten minutes.^[14]

The TerraVolt XR lithium nickel manganese cobalt oxide batteries^[5] were introduced in 2015 with improved range but slower charging, approximately one hour to full charge.^[14]

TerraVolt E2 batteries were introduced in 2016 with the longest range and slowest charging.^[13] The E2 battery range features a 3–5 hour charge time.^[13][15] E2 batteries have an energy density of 160 W-hr/kg and 260 W-hr/L, and use cells from LG Chem.^[16]

Batteries are carried under the Catalyst chassis, and use an interchangeable mounting system, so each Catalyst can hold between four and ten battery packs. The batteries can be swapped out, upgraded, or reconfigured as needs change.^[5]

Charging

Charging infrastructure alternatives

Overhead / en-route (Feb 2016)

Curbside (Nov 2015)

Under evaluation with King County Metro Transit at Eastgate Park & Ride

Buses can charge en route, allowing more trips and higher productivity for circulator or loop routes. One common example is to have charging stations at major transit centers. Two examples of this are the Washington Plaza Bus Terminal in New York and the Mill Woods Transit Center in Edmonton.

Charging rates range from 60 to 120 kW (using the SAE J1772 CCS ports) and from 166 to 350 kW (using a J3105 overhead fast-charger).^[17][18] In 2018, Proterra began offering the OppCharge (SAE J3105-1) overhead charger instead of its proprietary "blade" overhead charger.^[19]

Replacement

Main article: Proterra ZX5

On September 15, 2020, Proterra announced the replacement to the Catalyst, the ZX5. The ZX5 40' replaced the BE40 and the ZX5 35' replaced the BE35. Edmonton Transit Service was the launch customer, ordering 40 ZX5 40' buses.

Notable operators

Operator	Location	Model	Model Year(s)	Quantity
King County Metro	Seattle	BE40	2015	3
DC Circulator	Washington, D.C.		2017	14
NYMTA	New York City			5
SEPTA	Philadelphia			25
Toronto Transit Commission	Toronto		2019-2020	25
Chicago Transit Authority	Chicago		2020	25

Gallery

• 
  The rear of the Proterra Catalyst
• 
  A corporate-branded Catalyst testing in Washington.
• 
  A corporate-branded Catalyst testing in Minnesota.
• 
  A Catalyst BE40 of King County Metro
• 
  A Catalyst BE40 of the NYMTA
• 
  A Catalyst BE40 of DC Circulator
• 
  A Catalyst BE40 of Santa Clara VTA
• 
  A Catalyst BE40 bus of SEPTA
• 
  A Catalyst BE40 of Pioneer Valley Transit Authority.
• 
  A Catalyst BE35 of StarMetro
• 
  A Catalyst BE40 of Chicago CTA
• 
  Catalyst interior, looking back from forward aisle. Like other partial low-floor buses, there is a step at the rear axle for mechanical clearance.
• 
  Catalyst driver's seat and farebox
• 
  Catalyst instrument panel
• 
  Additional driver's controls
• 
  Front interior of Proterra Catalyst (MTA NYCT Spec)
• 
  Rear interior of Proterra Catalyst (MTA NYCT Spec)
• 
  Port Authority of New York and New Jersey Proterra Catalyst

Competition

• New Flyer XE35 Xcelsior CHARGE
• New Flyer XE40 Xcelsior CHARGE
• BYD K9M
• Nova Bus LFSe and LFSe+

External links

Test reports

• Federal Transit Bus Test, Proterra BE40 (PDF) (Report). Bus Testing and Research Center. May 2015.
• Federal Transit Bus Test, Proterra Catalyst E2 (PDF) (Report). Bus Testing and Research Center. September 2017.
• Federal Transit Bus Test, Proterra 35-foot Catalyst FC (PDF) (Report). Bus Testing and Research Center. June 2018.
• Federal Transit Bus Test, Proterra CAT35PD (PDF) (Report). Bus Testing and Research Center. January 2019.
• Federal Transit Bus Test, Proterra CAT40DP (PDF) (Report). Bus Testing and Research Center. September 2020.
• Federal Transit Bus Test, Proterra CAT40DP (800V six-pack) (PDF) (Report). Bus Testing and Research Center. October 2020.

References

1. Federal Transit Bus Test: 12 Year/500,000 Mile bus from Proterra, Inc. | Model BE40 (Report). Pennsylvania Transportation Institute. May 2015.
2. Federal Transit Bus Test, Proterra CAT35PD (Report). Bus Testing and Research Center. January 2019.
3. Federal Transit Bus Test, Proterra CAT40DP (Report). Bus Testing and Research Center. September 2020.
4. Federal Transit Bus Test, Proterra 35-foot Catalyst FC (Report). Bus Testing and Research Center. June 2018.
5. "Proterra Catalyst Platform Introduction" (PDF). Louisiana Alternative Fuels Conference & Expo. April 14, 2016. Retrieved July 13, 2018.
6. "Proterra 40 Foot Bus drivetrain performance" (PDF). Proterra. Retrieved July 12, 2018.
7. "The Proterra Catalyst 35-foot transit vehicle". Proterra. Retrieved July 12, 2018.
8. "UQM Technologies receives new orders for Proterra's Catalyst bus program for calendar year 2016 delivery" (Press release). UQM Technologies. November 5, 2015. Retrieved November 9, 2020.
9. "Transit Buses". UQM Technologies. Retrieved November 9, 2020.
10. "Proterra introduces two-motor DuoPower drivetrain for its Catalyst electric buses; partnership with Van Hool". Green Car Congress. October 9, 2017. Retrieved July 12, 2018.
11. "Parker Hannifin to showcase its latest mobile system solutions at bauma 2019" (Press release). Parker Hannifin. April 8, 2019. Retrieved November 9, 2020.
12. "Electric and Hybrid Vehicle Accessory, Power Generation & Traction Motor Solutions" (PDF). Parker Hannifin. 2014. Retrieved November 9, 2020.
13. "Proterra launches new Catalyst E2 series electric bus with nominal range of up to 350 miles". Green Car Congress. September 12, 2016. Retrieved July 12, 2018.
14. "Proterra introduces new extended range battery pack for electric transit buses; up to 180 miles". Green Car Congress. February 24, 2015. Retrieved July 12, 2018.
15. Marshall, Aarian (September 12, 2016). "This new electric bus can drive 350 miles on one charge". Wired. Retrieved July 12, 2018.
16. "Proterra and LG Chem announce co-development of new battery cell" (Press release). Proterra, Inc. September 19, 2017. Retrieved November 6, 2020.
17. "Catalyst Specifications: 40 foot bus" (PDF). Proterra, Inc. Retrieved November 6, 2020.
18. "Catalyst Performance Specifications: 35 foot bus" (PDF). Proterra, Inc. Retrieved November 6, 2020.
19. Kane, Mark (May 20, 2018). "Proterra Switches To SAE J3105 Standard For Overhead Charging". Inside EVs. Retrieved November 9, 2020.