'Cool' Fuel Cells May Soon Heat Up

'Cool' Fuel Cells May Soon Heat Up

Oct 01 - InTech

NEW THIN FILM SOLID OXIDE FUEL cells (SOFCs) may someday supplant traditional power plants, said researchers at the University of Houston.

"By using materials science concepts developed in our superconductivity research and materials processing concepts in our semiconductor research, we are able to reduce operating temperatures, eliminate steps, and use less expensive materials that will potentially revolutionize from where we derive electrical energy," said Alex Ignatiev, director of the university's Texas Center for Superconductivity and Advanced Materials (TcSAM) and professor of physics, chemistry, and electrical and computer engineering. "While there are a number of fuel cell research programs at the university, ours focuses on the application of thin film science and technology to gain the benefits of efficiency and low cost."

Compared to traditional fuel cells that can take up an entire room, thin film SOFCs are one micron thick-the equivalent of about one-hundredth of a human hair. If you take the size equivalent of four sugar cubes, the power generated could operate a laptop computer, eliminating clunky batteries and providing additional hours of use. The equivalent of two soda cans would produce more than five kilowatts, enough to power a typical household.

Keeping in mind that one thin film SOFC is just a fraction of the size of a human hair, with an output of 0.8-0.9 volts, a stack of 100-120 of these fuel cells would generate about 100 volts. When connected to a homeowner's natural gas line, the stack would provide the needed electrical energy to run the household at an efficiency of approximately 65%, researchers said. This would be a twofold increase over power plants today, as they operate at 30-35% efficiency. Stand-alone household fuel cell units could form the basis for a new'distributed power'system. In this concept, energy not used by the household would feed back into a main grid, resulting in a credit to the user's account, while overages would similarly receive extra energy from that grid.

These'cool'fuel cells operate at a much lower temperature than other solid oxide fuel cells, yet do not need a catalyst. Despite their 60-70% efficiency, SOFCs operate at 900 to 1,000 Celsius, a very high temperature that requires exotic structural materials and significant thermal insulation. However, a thin film solid oxide fuel cell has an operating temperature of 450 to 500 degrees Celsius.

"While there are a number of fuel cell research programs at the university, ours focuses on the application of thin film science and technology to gain the benefits of efficiency and low cost."

-Ignatiev