FUEL
CELL FAQs
Frequently
Asked Questions About Fuel Cells
What
is a fuel cell?
A fuel cell is an
electrochemical engine that converts the chemical energy of a fuel directly
to electricity. Almost always the fuel is hydrogen or a hydrogen rich
gas mixture. The fuel cell reaction is:
Hydrogen + Oxygen
(from the air) --> Electricity + Water + Heat
How
does a fuel cell compare with other energy production technologies?
A fuel cell is similar
to a battery in that both devices convert chemical energy directly to
electricity. However, a fuel cell never needs to be recharged, as does
a battery. As long as fuel and air are supplied, the fuel cell produces
uninterrupted electrical power.
Our usual way of generating electric power is through the steam cycle.
A fuel is burned to produce heat, the heat is used to produce steam,
the steam turns a turbine, and the turbine's power is used to turn
a generator to produce electricity. A fuel cell circumvents this complex
and inherently inefficient process by directly converting the fuel's
chemical energy to electricity in a single step.
What are the advantages of using a fuel cell?
A fuel cell is quiet,
clean, modular, and durable. No pollution whatsoever is produced during
operation. The only byproducts are heat (which cogeneration systems
utilize for water and space heating) and water. The product water is
pure enough that it is used as drinking water on board the space shuttle.
These characteristics make a fuel cell a good neighbor that can be used
for power even in densely populated urban areas where emissions requirements
are stringent.
A fuel cell operates at an efficiency of 40-50%, significantly higher
than conventional power generators. A steam power plant is typically
35% efficient, while the efficiency of an internal combustion engine
in most vehicles is only about 15%.
For
what applications are fuel cells useful today?
Fuel cells can be
used for:
-
remote
power: for off-grid homesites, field weather stations, telecommunication
repeaters
-
portable
power: for electronic devices as small as cell phones and laptop computers
-
vehicular power: for automobiles, trucks, boats, etc.
-
distributed generation: for stationary, on-site power generation
Remote power may
prove to be the first commercially viable market for fuel cells, especially
in applications where the noise, emissions, or fuel requirements associated
with conventional generators are a concern. Although fuel cell power
for cars gets a lot of attention these days, it may be a more difficult
market for fuel cells to reach, due to the relatively low per-horsepower
cost of conventional internal combustion engines and the robustness
and high power density required of a vehicular power system.
If
fuel cells are so great, why aren't we using them?
Fuel cells are actually
being used more widely than many people think. In addition to a few
high-profile applications such as the space shuttles, the organization
Fuel Cells 2000
lists over 600 past and present fuel cell installations worldwide on
their website. However, fuel cells are still meeting only a tiny fraction
of our energy generation needs.
There are two main reasons fuel cells have not yet caught on more broadly.
One, development work still needs to be done. Two, the price is currently
too high. There is nothing inherently expensive about a fuel cell but
as with most technologies, prices will not be competitive until many
units are sold. By demonstrating the practicality and environmental
benefits of fuel cell power, the Schatz Energy Research Center's
projects are an important step in advancing the worldwide effort to
make fuel cells widely available.
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