Tuesday, April 5, 2011

Bigger, is it Really Better?

Right now the electricity generation come from centralized power plants.  These plants are enormous, expensive to build, maintain, and produce large amount of waste.

Here are some quick examples of this.  Coal power plants produce around 45% of the electricity in the US.  The fuel necessary to run these plants is cheap and abundant.  However, these plants are only between 25-33% efficient at converting this fuel to energy while producing nearly 41% of all carbon dioxide emissions in the US.  Nuclear power is another large scale power generation system that is used.  Nuclear power can be used to efficiently create clean energy.  It accounts for roughly 13-14% of the worlds electricity.  It is vastly more effiecent are create energy then combustion reactions.  Nuclear power still is not without its drawbacks.  Disposal of nuclear waste in the US still has not been solved with place arguing where and how to store it.  The potential for a disaster affecting large areas is always around as scene in Fukushima, Three Mile Island, and Chernobyl.  So I was wondering don't we have something else, maybe something a little smaller?  That's were Solid-oxide fuel cells come in.

First lets discuss what a fuel cell is.  Fuel cells are a devices that acts like a factories that take in fuel (normally hydrogen) and convert it into electrical energy.  They are similar to combustion engine in this way.  Fuel cells are different because they have little to no moving parts meaning they do not need to expend extra energy to rotate a gear or pumps reducing the chance of mechanical failure.  Thanks to the way fuel cell convert fuel to energy there is very little emissions.  Fuel cells can easily vary in size and materials.  Solid-oxide fuel cells or SOFCs is a type of fuel cells that use ceramics as a means of conducting electricity.  Ceramics are used in fuel cell because they offer structural stability and fuel flexibility.  To achieve this fuel flexibility SOFCs must be operated at temperatures greater than 600°C.  Right now a company called Ceramic Fuel Cells Limited, based in Melborne, Australia, is developing a washing machine sized SOFCs that can power individual homes using natural gas.

BlueGen is the name of the small scale generator Ceramic Fuel Cells Limited is trying to market.  This device is currently 60% efficient at converting natural gas to electricity.  The BlueGen produces about 12500 kilowatts hours of electricity a year.  This is around twice as much as electricity consumed by the average Australian home.  Since the BlueGen is a SOFC heat is a byproduct.  With a special attachment the off heat can be used to warm water for the household.  Another advantage to the BlueGen is if one unit fails only one household is affect reducing the chance major harm.  This technology is looking so promising Ceramic Fuel Cells Limited has been selected as a finalist in DuPont Australia &New Zealand Innovation Awards recognizing the commercialization of outstanding science and technology.

With so many advantages to SOFCs I don't know why there use would spread throughout the world.

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