Even though the fuel cell was invented before the internal combustion engine, the two technologies have not been accepted into the mainstream at the same pace. NASA has been using fuel cell systems for decades in the space program, but much research and cost-cutting will have to be done before the technology can become an everyday power supply for industry, business, and homeowners.
The U.S. Department of Energy (DOE) wants to help make that happen.
Why is fuel cell technology worth the effort?
A fuel cell is a site for an electrochemical reaction combining hydrogen and oxygen; the end result is the release of electric energy, water, and heat. So, unlike traditional methods of producing electricity, fuel cell systems emit little or no carbon monoxide or other pollutants. And although fuel cells do require a supply of hydrogen — from a renewable energy source or a hydrocarbon fuel — they turn their fuel sources into electricity at high levels of efficiency and can help reduce our dependency on fossil fuels.
At Virginia Tech, DOE is funding a number of fuel cell research projects, some of them substantial and long-term. One is the Virginia Tech Center for Automotive Fuel Cell Systems, established in 1998 by DOE’s Graduate Automotive Technology Education Program and directed by mechanical engineering Professor Doug Nelson. Aimed at investigating ways of making fuel cell technology a viable alternative to the internal combustion engine, the center secured renewed support from DOE in 2005 (for more information about this center and other fuel cell research in the Virginia Tech mechanical engineering department, see the 2001 issue of Research, www.research.vt.edu/resmag/resmag2001/fuel_cell.html).
DOE also has renewed its support ($150,000 to $200,000 per year for the next three years) of electrical and computer engineering Professor Jason Lai’s successful efforts to increase fuel cell system efficiency.
During the past three years, Lai and his research team in the Virginia Tech Future
Energy Electronics Center have used their expertise in power electronics to boost DCto-
DC power conversion in low-voltage (22- to 50-volt) fuel cell systems to a power output of 400 volts DC and an efficiency level of 97 percent. This is beyond the 95 percent state-of-the-art efficiency achieved by industry research and significantly higher than the 75 to 80 percent efficiency that is the current industry standard.
But Lai is aiming at near perfection — a five-kilowatt (KW) fuel cell power plant that produces AC electricity from a DC source at a rate of 99 percent efficiency. A 5 KW fuel plant could, for example, provide all the electricity needed by a family living in a 2,000- to 5,000- square-foot home, Lai says.
To achieve 99 percent efficiency, Lai — who holds 13 power electronics patents and has another three pending — is developing a fuel cell power converter that will step up the electrical output from a low-power 400 volts DC to the high-power 120 volts or 240 volts AC that are standard for household and industry uses.
The second goal of Lai’s project is to develop a strategy for integrating 5 KW fuel cell power plants into utility energy grids. “The advantages to the electric industry will be the increase in efficiency and the reduction in emissions that fuel cell systems offer,” he says.
A third goal is to improve the efficiency of electric power use. “The utility grid voltage and current are not synchronized and that results in power losses,” Lai explains. “The lost electricity is still circulating in the system — whether the system is a utility grid or an air conditioner compressor — but it’s not being used and is causing power system instability. With power electronics we can correct the current angle and make it synchronized with voltage, thus reducing the loss of electric power.”
In addition to primary sponsorship from DOE, Lai has three partners in his fuel cell systems research — EPRI (Electric Power Research Institute) Solutions in Knoxville, Tenn.; Southern California Edison; and Siemans Westinghouse, which manufactures solid oxide fuel cell power plants and wants Lai to find ways to boost their efficiency.
Utilities and automakers are beginning to use fuel cell systems, and Lai expects there will be some installation of fuel cell power plants in homes within 10 years.
“A century ago, Thomas Edison dreamed that DC power could be distributed to every household,” he says. “But Westinghouse delivered lower-cost AC power through transformers and changed everything.
“Edison could have realized his dream if he had had power electronics to transform DCs,” Lai adds with a smile.
• Dr. Jason Lai’s webpage
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