Tuesday, November 14, 2006

Prototype Propane Fuel Cell

The Alaska Energy Technology Development Laboratory at the University of Alaska Fairbanks recently announced a successful field test of a prototype propane fuel cell.
The cell, manufactured by Massachusetts-based Acumentrics and installed at the Kenai Fjords National Park’s Exit Glacier Nature Center near Seward, ran for more than 1,100 hours straight and did so with no measurable degradation in its efficiency.
“From a technical point of view, it is an important milestone we have achieved here,” said Dennis Witmer, director of AETDL. “It is one step closer to these kinds of fuel cells becoming devices that can be useful in remote locations.”
The fuel cell was part of the original design for the nature center. It was first installed and used in the summer of 2004. Since then, a team of researchers and technicians has been fine-tuning the cell’s performance. In August, Park Service officials fired it up again and it ran until the end of the season.
“It’s not going back to the factory this winter. It has been mothballed for the winter and we plan on starting it up (next) summer,” said Tim Hudson, associate regional director for operations and resources for the National Park Service’s Alaska region. “We like the promise of this technology as a way to replace diesel generators, decrease the possibility of fuel spills and provide a cleaner and quieter source of power.”
The Exit Glacier fuel cell is notable for several reasons. It uses a fuel source--propane--that is more portable and usable in remote areas than the hydrogen or natural gas that usually powers fuel cells. It was also able to adjust its output to deal with fluctuations in power demand at the center, a phenomenon known as load following. And its most recent test run happened in real-world conditions, rather than in a laboratory with controlled power demands and constant monitoring and adjustment by technicians.
In addition, Witmer said, the Exit Glacier cell is able to efficiently generate relatively small amounts of power. A typical diesel generator is most efficient when it is generating 100 kilowatts of electricity, which is about 100 times more than a small building or cell phone tower would use.
“At one kilowatt, there is no convenient, efficient technology … and that is where fuel cells really have a hope of finding some market,” he said.
The reason for the efficiency is the way fuel cells generate electricity. Like a diesel generator, they use a hydrocarbon fuel source. But while the electricity in a traditional generator results from fuel burning and driving a mechanical generation device, the energy in a fuel cell comes from an electrochemical reaction.
“A fuel cell is a device that converts the energy from fuel directly into DC electricity,” Witmer said. “The idea is that the efficiencies are better with the direct electrochemical conversion, especially at lower power levels.”
In addition to generating electricity, the fuel cell provided heat to the nature center during its test run from mid-August to late September.
Witmer said that propane fuel cells are still a long way from being practical for the average consumer. However the successful test at Exit Glacier shows that the technology is meeting technical milestones. If the cells are eventually available to the public, it’s hard to predict all of their potential applications, he said, noting the number of devices that have come about as the internal combustion engine became smaller and more economical.
“Because we don’t have anything really good smaller than a diesel generator, we really don’t know what the demand would be for a one-kilowatt generator,” Witmer said. “That to me is the really exciting thing.”
The Exit Glacier Nature Center fuel cell test is the result of a cooperative agreement between the National Park Service and the Arctic Energy Technology Development Laboratory at the University of Alaska Fairbanks. Other funding partners include the U.S. Department of Energy’s National Energy Technology Laboratory, fuel cell manufacturer Acumentrics, the Propane Education and Research Council, fuel cell contractor Energy Alternatives, the Denali Commission and the Alaska Energy Authority

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