Sandia-industry team powers a mining locomotive with pollution-free hydrogen
A potentially revolutionary locomotive rolled into the hydrogen-powered age recently on a test track in Reno, Nev., energized by environmentally friendly fuel cells that a Sandia/California team added to the mining vehicle.
"This is the first ever built in the world, and we learned a lot," says Jennifer Chan (8731), lead engineer and project lead since October. "It’s a major step." The advance was welcomed by the mining industry, which bestowed a "best of show" award on the locomotive at the Canada Mining Expo last May.
In Reno, the four-ton commercial vehicle, originally designed to operate on battery packs, showed its prowess by pulling a 500-pound section of loose track at a Burlington-Northern (Kappes, Cassiday & Associates) warehouse sidetrack in Reno. The fuel cells supplied 8.5 kW power as the locomotive glided quietly along the 400-foot test track.
Fuel cells combine hydrogen and oxygen to create water, releasing energy but virtually no pollution. Although they are not yet mass-produced, fuel cells are routinely used in such cost-insensitive applications as powering the space shuttle.
In looking for a transportation market "point of entry," the Fuel Cell Institute, which proposed the project, selected mining vehicles as a potential economically viable initial application.
Nearly all mines employ diesel power, requiring expensive ventilation. Replacing diesel with hydrogen-powered vehicles would save an estimated 30-40 percent in ventilation costs, easily offsetting the cost of the fuel cells. "Those costs alone make this very viable economically," says David Barnes, project manager for prime contractor Vehicle Projects.
There might also be benefits to switching electric- and battery-powered mine vehicles for hydrogen-fueled ones, Barnes says. Batteries have to be charged overnight and switched out, while electric vehicles are tethered by long "extension cords" that present a hazard if run over. And if the electricity comes from coal-fired plants, its generation creates pollution.
The two fuel cell stacks, by the Milan-based company Nuvera, each have a maximum output of 7 kW. Sandia designed and built a metal hydride storage system to safely store the volatile hydrogen, absorbed onto a powdered metal alloy known as a "hydride bed" at the relatively low pressure of 150 psi. The bed can hold almost all the contents of six cylinders of hydrogen, which is normally compressed in the canisters to 2,000 psi.
The bed capacity lets the vehicle operate for a full eight-hour shift before requiring refueling above ground (which may take about an hour).
Sandia developed the "balance of plant" as well as the power plant for the locomotive. The balance of plant includes the water-cooling of the fuel cell, heating of the hydride bed (the heat from the fuel cell is used to heat the hydride bed for optimal operation), balance of air and hydrogen supply to the fuel cells, and the controls and safety systems. The power plant includes the integration of the hydride beds and balance of plant with the locomotive.
Following the above-ground safety assessment, the locomotive will be trucked in a temperature-controlled shipping container to Canada, where it will be compared to electric-powered locomotives at Val d’Or, a former metal mine maintained as an underground experimental mine.
"It’s a major, major step forward," says mining engineer Harry Bursey of project partner Warren Equipment. "If we handed out knighthoods, one would be involved." He anticipates the project will be a legacy to upcoming mine workers, such as his son, a geologic engineer in tunneling.
"Diesel exhaust fumes are not only uncomfortable," he explains, "they can be bad on health in the confined atmosphere of an underground mine, and in tunneling as well. The application of fuel cells to replacing diesel engines is absolutely vital. It’s a very forward-looking solution."
The project’s success could pave the way for production of some 150 hydrogen-powered mine vehicles per year.
The next aspect of the project, to begin this summer, is demonstration of a hydrogen-powered 100kW front-loader for mine use.
So far, nine Sandians have worked for two years on the project with the Fuel Cell Propulsion Institute, Vehicle Projects, the University of Nevada, Warren Equipment, Hatch consultants, the Canadian regulatory agency, MSHA, and Placer Dome and KC&A mining companies.
Besides Jennifer, team members include Ray Baldonado (8214), Ken Black (8120), Don Meeker (8724), Dan Morse (8723), Systems Engineering Dept. 8731 Manager Bill Replogle, Ken Stewart (8730), George Thomas (Sandia/California retiree/consultant), Dan Trujillo (8120), and Mark Zimmerman (8731). Jay Keller (8362) coordinates funding through DOE’s Office of Power Technology.