What is a Fuel Cell? What are
its advantages and its Disadvantages?
A fuel cell is an
electrochemical energy conversion device that converts hydrogen and oxygen into
electricity, heat, and water. It is very much like a battery that can produce
electricity while being recharged continuously.
Advantages of Fuel Cells
Basic fuel cells running
on pure hydrogen are pollution free, giving off only electricity, water, and
heat. The potential for fuel cells to provide zero or near-zero emissions has
been a significant force in the development of the technology over the past 30
years, and is drawing increasing attention to the technology today.
* Because there is no
combustion in a fuel cell, fuel is converted to electricity more efficiently
than any other electrical generating technology available today.
* There are no moving
parts in a fuel cell stack, making them more reliable and quieter than
generators. Even the ancillary systems (fans, pumps, controls) in a complete
fuel cell unit are relatively mature and simple technologies that should prove
extremely reliable.
* Unlike batteries that
must be disposed of once their chemicals are used up, fuel cell reactions do
not degrade over time and can theoretically provide continuous electricity.
* Traditional power
plants must be large in order to gain efficiency, but fuel cells can achieve
higher efficiencies at any scale, making them perfect for small portable,
residential, and transportation uses.
* Because fuel cells are
clean and efficient at any size, they can be located almost anywhere, including
dense urban areas where both air quality and transmission congestion may be of concern.
Fuel cells can offer an alternative to building new power lines, while also
reducing American dependence on foreign oil. Fuel cells can provide more
reliable power wherever electricity is needed, making the whole electric power
grid more robust and reliable. Distributed application of small fuel cells will
also enhance security of key infrastructures, such as our communication and
water systems.
* Economically, fuel
cells represent a prudent path to provide the country's electric power because
they can be installed quickly, are fuel flexible, and can be put in place
incrementally, mitigating the need for more costly and sweeping changes.
Disadvantages of Fuel Cells
In the past, fuel cells
were large and extremely expensive to manufacture, just as the first
calculators and computers were. But, just like these products, the cost of fuel
cells will quickly come down to consumer-affordable levels with mass
production. We are currently in a transition period now, where many fuel cell
companies are investing literally hundreds of millions of dollars to gear up
for mass manufacturing at the same time they are trying to begin to develop a
variety of markets for their product.
Currently, there is no
hydrogen infrastructure to supply coast-to-coast delivery of hydrogen fuel.
Technologies are being developed to provide alternative fuel storage and
delivery methods. SOFCs, MCFCs and PAFCs can internally reform natural gas,
providing the perfect solution for industrial use but MCFCs and PAFCs are too
large for home and transportation use and SOFCs still have years in
development. PEMs and AFCs can use fuel reformers to convert hydrocarbons, such
as gasoline and natural gas, into hydrogen, but this technology can lower the
overall efficiency of the fuel cell by 1/4 and can release small amounts of
pollutants. Onboard fuel storage and conversion solutions are being developed
but they are still years from being perfected.
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