This is part one of SearchDataCenter.com's update on fuel cell technology in the data center. Read part two here.
Fuel cells—is the future here already, or do we have to wait
It's not for lack of interest on the part of vendors. MGE UPS Systems had unveiled a fuel cell-based uninterruptible power supply (UPS) prototype in 2004, but "lack of customer interest/demand and the fact that the technology is still in its infancy for this type of application" caused MGE to cease work on it, according to a company spokesperson.
Several years ago, Siemens Power Generation was on the verge of introducing large-scale stationary fuel cells that by themselves could power an entire data center, but it decided to hold off and invest in the next generation of fuel cell technology, leaving it out of the market until at least 2008, according to information on its Web site.
Right now the two main players in the data center fuel cell market are UTC Power and American Power Conversion (APC). Each is targeting a distinctly different use of fuel cells.
UTC Power offers a stationary, on-site fuel cell product called the PureCell 200 -- essentially a 17-foot long box that can be installed inside or outside your facility and generate 200 kilowatts of power.
As you probably know, fuel cells need hydrogen to generate electricity, and the PureCell, like most on-site fuel cells of this magnitude, strips the needed element out of a piped-in supply of natural gas. Electricity (plus 925,000 BTUs per hour of heat—enough to keep your facility warm in the winter and provide enough hot water for even the most heavily caffeinated office) is generated using liquid phosphoric acid as an electrolyte.
The phosphoric acid fuel cell (PAFC) is a proven first-generation technology that has been in use at some pioneering facilities for a decade. The nation's largest such installation of PAFCs is in Garden City, NY, where Verizon has seven of UTC's 200-kW fuel cells powering a large call switching center and office building.
Dennis Hughes, the lead property manager at the First National Bank of Omaha, has been using PAFCs made by UTC in his facility since it opened in 1999.
"We have four fuel cells in the facility, but we only need two of those for our critical load," says Hughes. "We run all four fuel cells every day—what doesn't get used for critical load gets shared out for secondary load in the building. In the summertime, we will sometimes put our fuel cells only on critical load, let the rest be picked up by our three 1250-kW generators, and any excess power we have over we shove out through the transformers back to the grid."
In this scenario, Hughes sees the grid mostly as an unlikely source of backup power should one of the two redundant natural gas feeds to the fuel cells fail at the same time his diesel generators and flywheels stop working. "We think of the electric grid as our third line of defense: fuel cells being first, generators being second, and commercial power being third place." Suffice it to say that your next credit card purchase isn't likely to be lost to a blackout.
"We were looking for a system that would take us at least 20 years from the time the building was built until we'd have to think about doing anything else," says Hughes. "We wanted a system that would have at least the 'five-nines' of availability that our mainframe has." First National's fuel cells give them an extra two-decimal-place cushion—99.99999% availability.
As for cost, the fuel cells came out as winners when taking into account the cost of natural gas, excess power sold to the grid, and maintenance. It didn't hurt that the Department of Energy gave First National a rebate of $1,000 for every kilowatt of installed fuel cell power, either. The upfront cost of purchasing and installing a PAFC today is much higher than the cost of a diesel generator or gas turbine, but the 20-year payback is comparable due to the fuel cell's lower maintenance and better efficiency.
For a facility with a noise or emissions restriction, a fuel cell like this becomes an especially attractive option. The only case in which a non-fuel-cell option within UTC's lineup is more efficient is if you intend for your on-site power source to provide cooling as well as heating byproducts; a gas turbine generator can typically run a chiller's compressor while simultaneously capturing useful waste heat more efficiently than a PAFC can perform these functions.
On the horizon are solid oxide fuel cells (SOFC—the technology Siemens is betting on) and molten carbonate fuel cells (MCFC), each of which offer even higher rates of efficiency than PAFCs, but have several stability problems to work out.
About the author: Karim U. Khan is a freelance journalist based in Highlands, N.J. He is also editor-in-chief of corporate site selection publication, Business Facilities magazine.
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