Thursday, December 08, 2011

A Four Inch Fuel Cell That Could Power Your Car?!

Yes, it is possible to scale a fuel cell down to the point where it becomes small enough and economical enough to power a car and do so quite competitively.

Fuel cells have the potential to upwards of 3 times more efficient than the internal combustion tech used in vehicles today. However there is one major stumbling block. That of how fuel cells have to be fueled. Since the early days of the space program the emerging technologies surrounding the fledgling fuel cell depended heavily on hydrogen and oxygen not because they were inherently more efficient but the gasses were also used in many other systems aboard spacecraft. The downside of this was that in the public's opinion the only way to fuel a fuel cell was with these self same gases. And since hydrogen had developed a reputation of having zero pollutants it gained favor with both the public's and the appropriations committees. Now the technology is stuck in a spiral of waiting for an infrastructure to produce and distribute the fuel efficiently and at low cost. It could well take decades to create a nationwide hydrogen distribution and storage system, and to convert gas stations into a hydrogen filling station. This leads to the joke about Fuel cells being the tech of the future and always will be.

However, fuel cells do NOT have to run strictly off hydrogen to be clean and efficient. What the public has not been made aware of is that there are two types of fuel cells. Most people when they consider fuel cells think of the proton exchange membrane (PEM) fuel cell, uses hydrogen to generate power. However there is a competing technology - the solid oxide fuel cell (SOFC) developed by Professor Eric Wachsman, director of the University of Maryland Energy Research Center. The solid oxide fuel cell has a distinct advantage over the PEM type. The main advantage is that they can oxidize any fuel!

There are always trade offs, and here is the main one for the Solid Oxide fuel cell. (from the article)
  • "It's the reason why the automotive companies are using PEM fuel cells. PEM fuel cells operate at around 80° Celsius [180° Fahrenheit], which allows them to startup fairly quickly. Current solid oxide fuel cells currently operate at 800° Celsius [1500° Fahrenheit], so it takes a long time to warm up to operating temperature, making them more applicable to stationary power generation."

Wachsman and his colleagues have managed though to squeeze more power out of a smaller area at significantly lower temperatures. The group has also found that stacking their new arrays they get three kilowatts of electricity per kilogram of material, more than an internal combustion engine at approximately one-third the size. Also with changes in design they will be able to reduce the operating temps to around 650 degrees which puts the cell ideal for automotive applications.

More at the articles location here

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