Clean Energy on a roll

The newest shuttle bus operating on the UD campus consumes no fossil fuels and produces only a single emission—water.

The bus, unveiled during a ceremony April 9, is powered by hydrogen fuel cells. Supported by a $1.7 million grant from the U.S. Department of Transportation’s Federal Transit Administration, the project is matched by private financing from companies working in partnership with the University.

Researchers from the College of Engineering, who are driving the project, say they envision a multidisciplinary demonstration project. The team first researched and demonstrated ways to make hydrogen fuel cells more efficient and less expensive to produce and operate and then installed the cells in a public bus, which now is being tested as it operates on a regular passenger route around the Newark campus.

The project also includes development of a safe and efficient hydrogen refueling station to be used by the bus and, eventually, by other hydrogen-powered vehicles. Another goal of the project is to educate the public and transit officials about the developing technology of such fuel cells.

“A fuel cell vehicle has zero harmful emissions. Wisps of steam or a trickle of water—that’s all it produces,” Ajay Prasad, professor of mechanical engineering, says. Prasad is the principal investigator for the project, which is being coordinated by the Delaware Center for Transportation in the Department of Civil and Environmental Engineering. Co-investigators are Ardeshir Faghri, professor of civil and environmental engineering and director of the transportation center, and Suresh Advani, George W. Laird Professor of Mechanical Engineering.

“Most of the major automotive companies are aggressively pursuing fuel cell technology right now,” Prasad says. “When we sought this funding, we were not interested in just buying a fuel-cell-powered bus and operating it, which already is being done in some places. We wanted to introduce some innovations and inject some cutting-edge research on fuel cells into this project.”

The consortium working on the project includes EBus of Downey, Calif., which adapted its 22-foot, 22-passenger vehicle chassis and electric drive system for the bus; Ballard Power Systems of Vancouver, British Columbia, a major producer of fuel cells; Electric Power Research Institute of Palo Alto, Calif., which provided expertise and software; Air Liquide Advanced Technologies U.S. of Newark, Del., which provided a facility to house the bus and installed a hydrogen station next to it for refueling; and the Delaware Transit Corp.

The bus has twin, high-pressure tanks in its roof that can store 16 kilograms of hydrogen, with an estimated range of 200 miles.
Initially, the bus will operate on the University campus, with later demonstrations planned off-campus for the general public in collaboration with Delaware Transit Corp. During this period, the researchers say they will track performance, efficiency, control algorithms, emissions levels, operation costs, the frequency of maintenance needed and the ease of repairs.

Prasad, Advani and others in the mechanical and chemical engineering departments already are researching aspects of fuel cell technology. Faghri and others in the Delaware Center for Transportation have expertise in such fields as civil and transportation engineering.

“Companies throughout Delaware are very interested in this project,” Faghri says of the fuel cell bus. “The state has had a few alternative-fuel transportation projects before, but this is by far the largest. And, there’s a lot of work to be done, because we’re doing this for the first time. We want to move through research and development to a demonstration project, with commercialization as our eventual goal.”

The researchers identified three key hurdles to widespread use of hydrogen fuel cells to power vehicles—the cost of the cells, the ability to produce hydrogen on a large scale with minimal greenhouse gas emissions and the ability to refuel as needed.

“My feeling is that hydrogen fuel cells are eventually going to be common in hybrid buses and cars, where they would be combined with electric storage, in the same way that hybrids now combine gasoline and electric power,” Advani says. “The fuel cell technology exists now, but we have to overcome those hurdles. When that happens, maybe in 10 or 15 years, I think you’ll see a lot more cars powered by hydrogen.”

Prasad agrees, predicting that the problems of cost and access to hydrogen will be overcome in the next decade or so, through a combination of technological breakthroughs and mass production of cells and hydrogen fuel.

About 30 buses powered by hydrogen fuel cells currently operate in London and other European cities, Advani notes, with other fuel cell bus demonstration projects in progress in the U.S. and worldwide. Regionally, Georgetown University also is conducting a demonstration project involving fuel cell buses.

Almost all bus projects use large fuel cell stacks rated at 100 to 200 kilowatts or higher. The unique feature of the UD bus is that the fuel cell has been downsized to 19 kilowatts to match it to the urban transit driving schedule, which greatly reduces overall costs.

“To the best of our knowledge, this is the first fuel-cell-powered bus that has such a small stack,” Advani says. “If we can demonstrate that it can handle the urban transit drive cycle, it will take us one step closer to commercialization.”

Fuel cells convert the energy contained in hydrogen directly to electricity by combining it electrochemically with oxygen. Hydrogen and air flow into a membrane electrode assembly, which consists of two electrodes separated by a membrane, sandwiched between two current collector plates.

Hydrogen gas is separated into protons and electrons at the anode. The electrons flow through an external electrical load, while
the protons travel through the membrane to the cathode. There, they combine with oxygen and the returning electrons to make water.

Under the supervision of Prasad and Advani, researchers at the Fuel Cell Research Laboratory in UD’s mechanical engineering department make their own fuel cells and test them under different conditions in an effort to improve performance and efficiency. In addition, researchers in the chemical engineering department are exploring such questions as whether a less expensive substance could replace platinum as a catalyst in the fuel cell. (For more on this related research, see the following two pages.)

Prasad is enthusiastic about the participation of Air Liquide in the project, saying the company “single-handedly solved the problem of refueling our bus.” The company also has provided office space to two UD students to foster close collaboration.

Prasad says two hydrogen refueling stations are located in Washington, D.C., with another planned for New York. A station in Delaware, midway between those cities, would fit with federal plans to create “a hydrogen corridor” of stations in the Northeast, he says.
The bus is designed to serve as a public education tool as well as a research subject.

“We want the public to understand that hydrogen fuel technology is a viable and safe power source,” Prasad says. “Seeing a bus in operation will help convince people that this is the wave of the future in terms of clean energy.”

The research team also praised Delaware’s congressional delegation for supporting the project and the request for federal funds. “This project is important, not just for the University but for the whole state,” Faghri says.

Neil Thomas, AS ’76, and Martin Mbugua