Gas to electricity

New solid oxide fuel cell converts natural gas to electricity and auxiliary heat, long life predicted for Fairbanks unit

Patricia Jones

Petroleum News Contributing Writer-Fairbanks

Unique in its small size, a five-kilowatt solid oxide fuel cell fueled by natural gas — the key component of a $383,878 research project — was installed July 30 in Fairbanks, Alaska and began generating electricity and auxiliary heat two days later.

Incorporating a fuel cell stack built by Siemens Westinghouse, the electric generating unit was assembled by Ontario-based Fuel Cell Technologies for researchers at Arctic Energy Technology Development Laboratory, a part of the University of Alaska Fairbanks.

“This is the first (of its size) to run continuously on natural gas in the United States,” Dennis Witmer, director of the laboratory, told Petroleum News during a tour Aug. 5. “It’s been running 103 hours and has produced 405 kilowatts of power.”

The research project, funded mostly by the U.S. Department of Energy through its Arctic Energy office in Fairbanks, is housed at the administrative offices and warehouse of Fairbanks Natural Gas, the only commercial source of natural gas in Interior Alaska.

Fairbanks Natural Gas provided space and natural gas for the fuel cell unit, which weighs 2,500 pounds, and will use the electric power in its warehouse. In winter months, up to six kilowatts of heat will be funneled into the warehouse.

“We have no natural gas at the university … FNG was willing to house it, while our program pays all the installation costs. They’re not billing us for gas and we’re not billing them for electricity,” Witmer said. “They have a vested interest in letting this unit chug away.”

Also unique to this solid oxide fuel cell is a projected long life. Typically, this type of fuel cell begins to degrade after the first 1,000 hours or more of operation at a fairly rapid rate, Witmer said. Not so with this unit.

“The performance is supposed to improve for the first 10,000 hours, then start degrading,” Witmer said. “The degradation rate is much, much slower, about one tenth of a percent for every 1,000 hours, or approximately 1 percent per year.”

How long the unit produces electricity is one of three key points to the research project. Witmer said researchers will also monitor the unit’s efficiency, projected to be about 50 percent for power generation and up to 90 percent when including heat generated.

The unit’s entire operating system, which includes an inverter, switches and controls, ventilation system and a battery storage system, will also be monitored by researchers.

Consuming 30 cubic feet of natural gas per hour, the fuel cell heats gas to above 800 degrees Celsius, the point where that fuel reforms into hydrogen, creating the chemical reaction that generates power. A ceramic material that can withstand high heat contains the chemical reaction.

Siemens has previously produced 25 and 250 kilowatt solid oxide fuel cells for cooperative demonstration projects, Witmer said. This unit is designed for residential, small commercial and remote facility applications.

DOE is contributing $247,825 in funds for the purchase, installation and testing of the five-kilowatt solid oxide fuel cell. UAF will contribute another $135,053 to the project.