Past Event Coverage
Proterra Rolls Out Its Full-Size Battery Electric Transit Bus
‘Transit Can Have a Zero-Emission Future’
“This is the beginning of something big,” says Ryan Popple. He’s the new CEO of Greenville, S.C.-based Proterra (Booth 5037), which has recently shifted from 35-foot 100% pure battery electric transit buses to 40-foot vehicles more suitable to the transit market.
Proterra’s strategy is to build lightweight buses with relatively small battery packs. Operators quick-charge the buses at regular in-route stops, allowing the vehicles to perform a full day’s work with minimal disruption.
A “V2” Proterra bus is in Altoona trials now. “Transit,” says Popple, “can have a zero-emission future.”
“This is an important conference for operators to seriously start considering electric transportation for their fleets,” he says of APTA Expo 2014 in Houston.
Proterra’s largest customer, Southern California’s Foothill Transit, is the lead customer for the new 40-foot model, having ordered two to supplement 15 of the 35-foot originals.
Seattle King County Metro subsequently ordered two of the 40-foot Proterra buses, with options for as many as 200 more.
The V2 bus is 1,000 pounds lighter than the firm’s 35-footer, approximately 60 of which are either in-service or on-order, Popple says.
Proterra said last month that Japan’s Toshiba will supply SCiB brand lithium titanium battery modules for the new 40-footers. The second-generation V2 buses have motors and controllers from UQM Technologies, and a two-speed transmission developed with Eaton.
Eaton (Booth 4201) also furnishes the high-power DC chargers used for in-route charging. The Toshiba batteries, designed to accept repeated fast charges, help make the Proterra in-route charging strategy possible.
“With a rapid recharge capability and outstanding life performance, Toshiba’s SCiB battery is ideally suited for zero-emission public transit,” said Toshiba International power electronics VP Greg Mack.
Proterra has configured the 40-foot V2 with eight active liquid-cooled Toshiba SCiB modules affording 100 kilowatt-hours of energy storage.
The Toshiba units, with BMS/battery management system designed and programmed by Proterra, is located in the bus undercarriage, improving center-of-gravity and vehicle handling and easing access for maintenance.
“We are very deliberate in each part we select for our buses, putting vendors through a rigorous qualification process,” said Popple. “Battery quality is critical to the performance of electric vehicles,” he said. “SCiB technology will enable Proterra to offer its customers the highest-performance, safest, and most reliable urban transit vehicles.”
Single-charge range is a “nominal” 50 miles, but Proterra prefers to state it at a conservative 30, Popple says – a figure operators can count on even if hauling a full load of 70 passengers, running air conditioning or heating, and doing so at the highway speeds necessitated for some suburban routes.
With the two-speed Eaton gearbox, he says, “You get a tremendous amount of low-end torque for city driving [and hills], and shift to highway speeds with high efficiency for suburban drive cycles.”
The 40-foot Proterra V2 is priced at $825,000. Deliveries are to start this year or early next. Production of the existing 35-footer – Popple calls it the V1.5 – is now expected to extend into early 2015, he says, behind follow-on orders from existing operators.
In addition to Foothill, Proterra transit customers include San Joaquin RTD in Stockton, Calif.; RTC in Reno, Via Metropolitan in San Antonio; StarMetro in Tallahassee; the City of Seneca, S.C.; Nashville MTA; TARC in Louisville, Ky; and Worcester RTA in Massachusetts.
Proterra buses have logged nearly half a million miles.