Two CTA buses powered exclusively by batteries entered service Wednesday in a $2.5 million electric bus experiment that transit officials expect will be good for the environment, public health and the agency’s bottom line over the long run.
The two prototype all-electric buses, which will be operated initially on six bus routes that serve the downtown area, will be easy for riders to spot. They are painted in shades of green and labeled “electric bus” over the window line.
The telltale signatures of diesel engine buses — plumes of dark smoke blowing out of the tailpipe and a grumbling engine sound — are replaced by a soft whine when the electric buses accelerate.
“It’s just a smoother ride. A cleaner ride too,” bus instructor Don Winston, a 30-year CTA veteran, said before taking reporters on a road test Wednesday morning, hours before the two electric buses, which are outfitted with lithium-ion battery packs on the roof, entered service.
The ride was indeed smoother. There was less vibration as the result of no large rear-mounted engine shaking the vehicle, and start-ups after red lights were more even.
Features inside the electric buses look similar to those in the CTA’s standard buses. But there are some differences. For instance, the seats are lighter to help improve efficiency and the doors are electric-powered instead of air-powered, officials said.
Although other U.S. transit systems have tested all-electric buses, the CTA is the first major transit agency to use the vehicles as part of regular service, said George Cavelle, CTA vice president of vehicle and facility maintenance.
The 40-foot green machines, which as prototypes are priced at about $1 million each, are made by New Flyer Industries. The all-electric propulsion system was built by Siemens.
Regular diesel-powered buses cost $400,000 to $500,000 each, and diesel-electric hybrid buses cost about $700,000, according to the CTA.
The CTA will test the electric buses in service over the next year or so before deciding whether to buy more of vehicles, Cavelle said.
“We already know these buses will be easier to maintain, in terms of not having to change oil like you do with an engine and not having to repair hydraulic lines that run through a conventional bus,” he said.
The big unknown is how far and how long the buses will be able to travel on Chicago’s congested streets and in the city’s challenging weather before needing to be plugged in to an electric outlet for a recharge.
CTA officials said the buses are expected to run 80 to 120 miles, or virtually a full operational day, between recharges, which will take about five hours. CTA buses operate an average of 100 miles per day, officials said.
Charging stations have been installed at the CTA’s Kedzie garage and at a bus maintenance facility, officials said.
CTA officials estimated the electric buses will reduce energy costs by more than $25,000 a year per bus, or roughly $300,000 over the average 12-year bus life span.
The electric buses are not emissions-free; they have a diesel heater for the interior. But operating vehicles that are almost pollution-free would improve air quality if used fleetwide and lead to a reduction in respiratory diseases, which alone is valued at about $55,000 annually per bus, officials estimated.
The electric bus demonstration project is funded by a $2.2 million grant received in 2011 from the Federal Transit Administration, plus about $300,000 in congestion mitigation funding, officials said. The yearlong test was originally expected to start last year, the CTA previously said.
The two prototype electric buses will be used on the following routes: No. 7 Harrison, 120 Ogilvie/Streeterville Express, 121 Union/Streeterville Express, 124 Navy Pier, 125 Water Tower Express and 157 Streeterville/Taylor, the CTA said.
Among the current fleet of roughly 1,800 buses, about 1,500 have diesel engines and 308 are diesel-electric hybrids, officials said.
The fuel efficiency of CTA buses ranges from about 3 mpg on conventional combustion-engine buses that operate on clean diesel to about 5 mpg on diesel-electric hybrids, said Marc Manning, the CTA’s project manager for the electric buses.
The CTA converted its bus fleet to ultra-low-sulfur diesel in 2003, three years before the U.S. Environmental Protection Agency mandated its use, the agency said.
All buses delivered since 2007 have clean-diesel engines and particulate filters that meet EPA emissions standards, the agency said.
The CTA has experimented with true zero-emissions technology. In the late 1990s it tested hydrogen-powered buses that emitted nothing but pure steam.
The exhaust emission from the hydrogen fuel cell-powered vehicles was unadulterated water vapor. Mayor Richard M. Daley toasted what he predicted would be the future of clean-fuel buses when he drank a glass of water collected from the tailpipe of a prototype bus on LaSalle Street.
The CTA tested the buses on several routes downtown, but the cost of the vehicles — $1.4 million each, compared with the $280,000 price of diesel-powered buses at the time — was ultimately deemed prohibitive.
The CTA has also tested buses that run on compressed natural gas and biodiesel.
So-called “soybean buses,” conventional diesel-engine vehicles powered by a mixture of diesel fuel and waste vegetable oil collected from restaurants’ deep-fat fryers, were tried in the early 1990s. City environmental officials declared the pilot program a success, but riders complained that the buses smelled like greasy french fries.
jhilkevitch@tribune.com
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