Environmental Progress - Spring 1998

Zero Emission Buses Hit Chicago Streets

Instead of black smoke, they produce only water clean enough to drink.

The world’s first pollution free buses have begun carrying passengers in Chicago. Powered by hydrogen cells, the buses create energy through an electrochemical process that converts hydrogen directly into electricity without combustion or pollution. Instead of the billowing clouds of black smoke usually associated with diesel-powered vehicles, the buses generate only pure water vapor.

The first $1.4 million bus was delivered in September, and was followed by two others to round out the fuel cell fleet during a two year performance study.

Operators received training in operation and maintenance of the revolutionary vehicles before they were put into revenue service.

The hydrogen cells were developed by Ballard Power Systems. A hydrogen fueling station at the CTA’s Chicago Avenue garage, built and operated by Air Products & Chemicals Inc. of Allentown, Penn., will supply the hydrogen which is derived from natural gas.

Funding came from federal Congestion Mitigation and Air Quality grants and the Regional Transportation Authority. Spare parts, maintenance, training, and engineering are expected to cost $1.6 million, and cost of the hydrogen fuel and construction of a fueling station is estimated at slightly under $1 million. Another $2.9 million was provided by the FTA and the RTA to modify a Chicago transit bus garage to house the vehicle and to pay for associated costs. In all, $9.6 million was allocated for the project.

CTA President David Mosena hailed introduction of the buses, which he said "will allow us to make strides toward providing the city with pollution-free bus service."

"The investment in a project like this is huge," he added, "but no price tag can be placed on cleaner air for generations to come or the quality standard of providing safe, on-time and truly clean service to our customers."

Performance characteristics of the zero-emission buses compare favorable with more conventional mass transit vehicles. They meet performance criteria established under the Urban Mass Transit Authority, are basically the same size and use the same material components of conventional buses. They are nine inches higher than diesel buses, to allow for tanks carrying the compressed hydrogen, and when empty weigh 32,000 pounds compared to 27,500 pounds for the conventional vehicles.

Currently, the Ballard engines are providing 46 percent fuel efficiency, compared to 20 percent for conventional diesel engines. With planned subsystem improvements, the zero-emission engines are expected to exceed 50 percent efficiency.

During their two year test period, the three zero emission buses will be operating on routes that will take them through the downtown area where highest concentration of vehicular pollutants are generated.