A commercial design of an advanced fuel cell - the building block of
a family of environmentally super-clean, fuel-flexible power plants -
has passed several milestones in a joint public-private development effort.
The Direct FuelCell is a versatile, combustion-less
power source being developed in the Department of Energy's fuel
cell research program. It can use natural gas, methanol, ethanol,
bio-gas or other hydrogen-rich fuels.
FuelCell Energy, Inc. has completed one year of commercial design validation
and endurance testing of a 250 kilowatt-class Direct FuelCellTM (DFCTM)
power plant at the Danbury, Connecticut headquarters. The "direct"
in the name refers to internal conversion of fuel gas to hydrogen instead
of externally in a separate unit. This approach reduces costs and makes
more efficient use of what would have been wasted excess heat.
The demonstration included the longest running (8600 hours) carbonate
fuel cell fuel cell stack ever as well as the largest. Beginning operation
in February 1999, this grid connected power plant used a full-size stack
of 340 nine-square foot area cells. The stack was manufactured at the
company?s state-of-the-art production facility in central Connecticut.
This stack is the building block for FuelCell Energy's family of commercial
products ranging in size from 250 kilowatts to 3 megawatts.
The next step toward commercialization will be field trials of the packaged
"FuelCell Energy's one-year anniversary of the start up of this
advanced power plant is a major milestone in our efforts to develop the
clean energy systems of tomorrow," said Rita Bajura, Director of
the National Energy Technology Center. The Center is the primary technical
arm for the Energy Department's Fossil Energy advanced power systems program.
"This is not a small scale laboratory experiment but rather a full-sized,
grid-connected power plant that has been powering FuelCell Energy's own
facilities and providing power to the local utility grid for a year,"
Bajura said. "It has been running in an unattended mode for the past
eight months and has operated exactly as designed, delivering clean, high
quality electric power efficiently, quietly and reliably."
In parallel with its Danbury stack validation testing, FuelCell Energy
has been negotiating and starting field trials for benefit of interested
customers. Negotiations have resulted in commitments for sub-megawatt
field trials planned for a Mercedes Benz automobile production site in
Tuscaloosa, AL and for a site served by the Los Angeles Department of
Water and Power.
Meanwhile, field trials of the sub-megawatt FuelCell Energy stack successfully
started in Europe in November 1999 at Bielefeld, Germany by the company's
European partner, MTU, a unit of Daimler-Chrysler. The MTU unit provides
225 kilowatts of electricity with utilization of waste heat. The unit
showed overall thermal efficiency of 77% with 45% fuel-to-electricity
All of the demonstrations, including the Danbury system operate on pipeline
natural gas. In the DFCTM pipeline gas is directly fed to the fuel cell
stack, which results in a simple reliable and cost-effective system.
The Danbury plant uses a full-size stack (the commercial building block)
and operates at atmosphere pressure. Multiples of the basic stack building
block will be used by FuelCell Energy to construct megawatt-class power
plants. The achievement is significant for both the 250 kilowatt- and
megawatt-class power plant types because no further scaleup of stack size
is required for commercialization.
During the one-year operation, the plant has delivered more than 1.3
million kilowatt-hours of electricity. It was intentionally subjected
to six thermal cycles (including one with fuel supply loss simulated),
different types of emergency trips, and other robustness tests.
This new power generation system's ability to respond to load demand
in seconds has also been demonstrated.
The Danbury power plant operation verified that the DFCTM exhaust is cleaner
than the U.S. Clean Air Act standard. The emissions of nitrogen oxides,
sulfur oxides, and carbon monoxide are <0.1 ppm, <0.01 ppm, and
<1.0 ppm respectively.
In a similar parallel test of full-scale cells, an 8 kilowatt DFC stack
has logged 14,000 hours on multiple types of fuels, helping to verify
the logevity and fuel versatility of the technology.
Dr. Mark Williams, the Energy Department's Fuel Cell Product Manager
at NETL said, "The potential value of fuel cells is already widely
recognized. We are very pleased with the operational ruggedness of FuelCell
Energy's 250 kilowatt system as a whole and the endurance results of the
prototype commercial cells in particular."
Dr. Williams said that the next steps to commercialization of the DFC's
are field trials currently underway and high volume manufacturing required
for lower cost commercial production.
The milestones are part of the U.S. Department of Energy's Cooperative
Agreement with FuelCell Energy. The program is managed by National Energy
Technology Laboratory in Morgantown, WV and Pittsburgh, PA, under the
DOE Fossil Energy. Its goals are to enable industry to take advantage
of fuel cells by reducing costs and enhancing performance, and to strengthen
the nation's economy by developing American leadership in manufacturing
fuel cell systems.