The No. 66 bus is packed on a recent weekday afternoon as it travels from Chicago’s near west side to Navy Pier along the Lake Michigan shore and closes its route.
The seats and windows squeak and rattle like a regular diesel bus, but nobody seems to notice the high-pitched whine of the electric motor that drives it.
The Chicago Transit Authority wants just that. Buses that don’t pollute the air can still run routes with the same reliability as they do, even when cold weather cuts battery range.
Yet to make electric buses work, the CTA has had to go to great lengths and expense. It built fast-charging sites at both ends of the No. 66 route that plug into bus roofs.
Drivers constantly monitor the batteries to make sure they don’t wear out, putting the bus at risk of becoming stranded. If they charge less than 50%, they should top off the charger.
“We’re working through the day-to-day challenges of inclement weather in Chicago,” said Don Hargrove, senior maintenance manager at the garage that is home to most of the authority’s 23 electric buses.
The CTA began experimenting with electric buses in 2014 and has developed a system that Hargrove says will see the transit authority move to an entirely electric fleet by 2040.
Other transit systems are going through the same process to reduce pollution and help fight climate change.
Cold weather is the CTA’s biggest problem. As temperatures drop, the lithium-ion batteries powering the buses are not as efficient and lose range. Most of the energy from the battery goes into heating the interior of the bus to 70 F (21 C).
Richard Lynn, assistant chief bus equipment engineer, said, “Whenever the bus stops to pick up passengers, let people go, the doors open.” “You have to warm up that new batch of cold air.”
Lin said the electric buses have a small diesel engine that heats the interior in extreme temperatures to increase battery range. But most of the time the buses use electric coil heaters, similar to a giant toaster, which can zap the battery. When the CTA bought its buses, more efficient heat pumps were not available as an option, he said.
For every 10-mile one-way trip on the No. 66 route, electric buses lose about 8% of their battery energy. In the winter, they start with about 100 miles of range on a full charge. So after about six one-way trips, the policy says to charge drivers as they drop below 50%.
Typically the schedule calls for 10 to 15 minutes of charging, and the buses receive approximately 1% of a full charge for each minute they are plugged in.
Lin said that with enough chargers, electric buses could run on all routes. “Putting chargers in the right locations, having enough chargers available as we grow our fleet, is a matter of our strategy.”
Currently, the CTA has about 1,900 buses, and most run on diesel fuel. Transit systems are starting to swap them for electricity, but the investment is huge. Each electric bus costs about $1.1 million, about $500,000 more than a diesel model.
But after the initial capital outlay for the buses and charging stations, electric buses are much less expensive to operate. The CTA has calculated that it costs $2.01 per mile to operate 40-foot-long electric buses. It’s $3.08 for a diesel bus and $2.63 per mile for a diesel-electric hybrid.
It will take decades for the authority to recoup its investment in electric buses, but CTA officials say the cost of electric buses will go down because there will be more sales.
In Juneau, Alaska’s capital, which has a more temperate climate but winter temperatures can still dip below zero, officials also have plans for a fully electric bus fleet, though the one they got in 2020 has been hit by mechanical problems. suffers from
Capital City Transit has ordered seven electric buses since 2010 to replace diesel models, said operations superintendent Rich Ross. “The new buses are expected to run on regular routes because of the increased battery capacity,” he said, “which was not available when we ordered our first bus.”
Ross said cold winter conditions could still knock 100 miles off the new buses’ expected 282-mile range, so on the coldest days, they could be placed on commuter routes that only operate during peak transit hours. Let’s go
Like Chicago, Capital City Transit plans to build “en route” charging stations for buses to plug in when they’re running low.
Back at No. 66 in Chicago, Don Carter, 54, says he’s glad electric buses are running the route because they’re good for the environment.
The only difference is that electric buses are quieter than rattling diesel engines and noisy heaters, but few people notice, she says. “When I’m coming to work, everyone is rushing to get to and from the bus,” she says. “It’s just quieter. It’s easier to talk to people. When the heat goes up and you barely notice it.