Designed to lessen the impact of public transport on the environment, Proterra’s all-electric buses were added to the Citibus fleet in Aug. 2019. Although there are only a couple of these buses currently on campus, Chris Mandrell, general manager at Citibus, said they travel on average 150 miles each day on the Red Raider and Double T bus routes.
Citibus has deliberately used these new buses sparingly. Despite the positive early reception received from Lubbock residents, Mandrell said the long-term reliability of these vehicles remains to be seen.
While a diesel engine in a conventional public bus contains roughly 3200 parts, Mandrell said the engines used in Proterra buses contain only four parts: a rotor, stator and two bearings. Streamlined and efficient, these new electric buses have brought a long-awaited update to the Citibus fleet.
“If you were to convert the (electricity) used to (diesel), this bus would be getting 18 miles to the gallon,” he said. “There’s a readout on the digital display of the dashboard that tells the driver an approximate conversion of how its efficiency equates to a diesel bus.”
The buses, each one 40 feet in length, were obtained by Citibus through the Low or No Emission Vehicle Program, or 5339(c) Program, Mandrell said. In 2017, Citibus and the City of Lubbock received $1,750,000 for two Proterra buses as well as its on-route fast charger and bus depot charging station.
This federal grant provides funds to local and state entities to incentivize investment in zero-emission and low-emission transit vehicles, according to the United States Department of Transportation website. The grant program was established under Fixing America’s Surface Transportation Act, or FAST Act, introduced in the House of Representatives on Jan. 6, 2015 by Representative Rodney Davis (R-IL).
Replacing a bus in a city’s public transport fleet is pricey, Stacy Stockard, media relations coordinator for Texas Tech Transportation & Parking Services, said. Traditional diesel buses cost between $250,000 to $500,000 and electric buses can cost up to $750,000.
Side-view of a Proterra electric bus as it heads south bound on Akron Ave., towards Memorial Circle. Photo by Reece Nations.
“In 2015, we had worked with some consultants that deal with busing to just evaluate what was going on, if needs were being met, how all of us needed to adjust,” Stockard said. “And so, one of the things that came up in that survey was that most of the fleet was beyond the typical lifespan for buses.”
The consultation determined that even though the buses on Texas Tech’s campus were still safe for use and in satisfactory condition, they were older than an average public transportation vehicle, Stockard said. The average lifespan of a public bus is 12 years nationally, and the average age of a Citibus at Texas Tech University was 14 years in 2015.
Citibus plans to add more electric buses to their fleet, but making the fleet all-electric is not currently a priority, Mandrell said. Currently, the buses’ charging station is connected to the Lubbock Power and Light electrical grid and is therefore not as sustainable as it would be if solar panels were enabling the charging process.
Interior view of a Proterra electric bus, devoid of all passengers. Photo by Reece Nations.
“By working with LP&L, we’ve found that we can save about eight-hundred bucks a month if we charge (the buses) one after another,” he said. “It’s because of the way that they do their billing. They have a demand charge, so it benefits us more if we don’t charge them simultaneously.”
The Port Arthur Transit Department, VIA Metropolitan Transit in San Antonio, Capital Metropolitan Transportation Authority in Austin and Dallas Area Rapid Transit have all also integrated electric buses into their fleets, according to the Federal Transit Administration website.
Each electric bus saves 250,000 pounds of carbon dioxide each year if driven 45,000 miles annually, Dale Hill, founder of Proterra said. Hill, one of the nation’s leading innovators in battery-electric bus technology, had the designs for Proterra’s buses patented.
“We have four-hundred buses in service around the United States and Canada,” Hill said. “And so, we have a pretty good history on maintenance.”
Over a period of eight years, Hill said Proterra’s buses have led to an average of $150,000 in savings related to maintenance costs for transportation providers. Once obtained by a transit agency, Proterra provides a service technician who can train their mechanics to maintain and fix the electric buses.
Proterra’s cloud-based bus maintenance monitoring system can also be used to diagnose issues with the buses mechanical and electronic systems, he said. From the coolant systems to the taillight bulbs, any irregularity detected by the service will notify a service technician of the issue.
“Proterra is the only bus manufacturer out there that builds a bus from the ground up to be a battery-electric bus,” Hill said. “Everybody else is taking a diesel bus and trying to retrofit it. The result is, we’re able to build a lighter vehicle because our batteries are located within the floor of the bus.”
About Reece Nations, Managing Editor
