Finding a Spark

Listening to Foothill Transit’s director of operations, George Karbowski, it is easy to see how similar transit is to hobbies. In Seoul, South Korea, an amusement park tram is running on electric power fed from strips imbedded in the road — like a slot car track. And Karbowski’s zeal describing the new Proterra buses Foothill Transit unveiled this spring is like a kid opening his first electric radio-control car. And that’s what these new buses most resemble, not hybrids, not plug-in hybrids, but quick-charge radio control cars — although it should be noted the buses aren’t radio controlled.

“This is really a terrifically exciting project,” Karbowski says.

He explains that the whole project started while discussing what to do with some federal stimulus dollars Foothill Transit received. Karbowski says in a moment of weakness he raised his hand and asked about electric buses, and it just went from there.

“My wife said, that’s what you get for opening your mouth,” he laughs.

Karbowski says the Foothill Transit board has been the real motivating force behind the project. When it was brought to motion, the entire executive board seconded it, a first in Foothill’s history.

Karbowski says the order is for three buses by this summer with an option for nine more. That is if these new electric buses prove their mettle in service.

“The key to demonstrating this project, when everybody talks about electric buses they talk about how many miles can you go on a battery charge,” Karbowski says.

“Well, we’re deploying these buses within a system and that system includes an in-route charger. So we tell everybody the mileage is unlimited when it’s running in this system. It can literally run 24-hours-a-day seven-days-a-week.”

The initial three buses plus the option for nine more will allow Foothill to completely electrify one line. And it’s not just any line, it’s a critical line to the system.

“We’re not hiding this in the back corner. We put it on a line that carries about 5 percent of our annual ridership with only 2 percent of our buses,” Karbowski says.

“It is a very transit dependent line. It travels by schools, hospitals, DMVs, Social Security. It has a high wheelchair ridership. It’s a line that requires a workhorse bus.

“We don’t want to bring a niche electric vehicle in and say oh yeah we’re running it for the sake of doing it. We want to demonstrate that this is a true transit option.

“And then if we can validate the lifecycle costs, operating that kind of service then you know the future could be just about anything.”

Electric Power

Karbowski explains that the secret to these buses really lies in its batteries.

“There are a couple of things that lend themselves to making this project a reality, but probably the single most important item is the development of new battery technology, Karbowski says.

Karbowski explains that lithium ion batteries will accept huge amounts of charge and discharge very quickly.

“With a conventional lead acid battery or a NiCad or a variety of other batteries that are out there, when you try to charge or discharge them very quickly they build up really high heat because of the resistance in the anode and cathode,” Karbowski says.

“The lithium ion battery — the chemistry of the battery — it doesn’t do that. They do generate some heat during charging, so the battery system does have its own cooling system.”

The batteries Foothill is using were designed by Altairnano and are actually lithium-titanate because of the titanium used for the batteries anode and cathode. Karbowski says that they chose these batteries because titanium anode and cathode material has the highest charge and discharge amount.

“So again it’s a factor of you can plug huge amounts of electricity into the battery, but it either won’t accept it because of high resistance or build up a lot of heat. The lithium ion batteries do not do that, so that’s what is really the driver for the project,” Karbowski says.