WASHINGTON, Nov. 19 (UPI) -- Canadian and American scientists have made progress commercializing devices that generate electricity from the chemical reaction that creates water, researchers said Tuesday.
Many scientists and environmentalists consider fuel cells, as the devices are called, to be one of the best alternatives for meeting the planet's growing energy needs. Unlike systems that burn fossil fuels, they operate without exhaust gases thought to contribute to global warming.
A team at the Alberta Research Council is focusing on miniaturizing the devices, while work at Lawrence Berkeley National Laboratory in California aims at toughening the heart of a fuel cell for residential uses.
The ARC project, overseen by research scientist Partho Sarkar, is working to shrink fuel cell designs based on electrodes laid atop a ceramic base. The latest result is a prototype tube-shaped cell only 2 centimeters long and 2 millimeters in diameter, somewhat smaller than a AAA battery, capable of running a small electric fan.
"For a calculator, which only needs a low voltage, you could use one cell," Sarkar told United Press International. "For larger portable devices, which need 3 to 5 volts, we would have to put together a stack (of cells)."
Dean Richardson, a venture manager at ARC, said the project originally aimed at transportable power applications, akin to today's small gas-powered generators. Replacing batteries in handheld devices has turned out to be another attractive option, he said. Commercially available products are about two years away, he added.
One byproduct of all fuel cells is heat, but the idea of using a tubular configuration can effectively deal with that in a small space, said Steve Visco, a researcher at Berkeley's Materials Sciences Division.
"A (flat) configuration can undergo a lot of thermal stress when the fuel cell starts up, but a tube doesn't have nearly the same problems," Visco told UPI. Similar designs can have interior temperatures many times the boiling point of water yet their surfaces will be cool to the touch, he said.
Heat also is key to the Berkeley team's work. Fuel cell systems of the type the lab is researching currently run at about 1,000 degrees Celsius, requiring the use of expensive ceramics and limiting their useful lifetimes, Visco said. Lowering the temperature would allow stronger, less costly steels to support the fuel cells.
The Berkeley team devised extremely thin electrodes set atop a porous stainless steel base about 2 millimeters thick. This combination can operate efficiently at between 600 and 800 degrees Celsius, about the same as the burner in a residential water heater, Visco said.
The lower-temperature fuel cell is expected to go into residential power units putting out about 5 kilowatts, Visco said, more than enough to take the strain off of electricity grids during peak demand. Smaller versions could go into recreational vehicles, removing an emissions source from remote locations such as national parks, he said.
A Spanish company is interested in commercializing the Berkeley design, he said, and the team hopes to deliver a demonstration model within 18 months, with mass-market versions following in another year or so.
The ARC researchers also are interested in developments with the metal-based fuel cell stack, Sarkar said. The Canadian designs could be improved by these developments, he said, particularly with regard to the lower operating temperatures.
Both teams are trying to reach a cost goal of $400 per kilowatt, which would make fuel cells economically competitive with gas-turbine generators. Current fuel-cell systems have costs running about 10 times the research goal, Visco said, while the materials going into the stainless-steel fuel cell stack amount to only $37 per kilowatt.
