Fuel Cells
A fuel cell is a device that converts chemicals into electricity. A battery
also converts chemicals into electricity, but the difference between batteries
and fuel cells is that fuel cells have a continuous supply of chemicals for the
conversion process.
The most common type of fuel cell uses hydrogen and oxygen. The fuel cell
converts these into water and in the process creates electricity. The fuel cell
creates direct current (DC) electricity which can be used to power lights,
motors, and many appliances.
Fuel cells are very clean source of energy. The technology behind them is still
developing, but eventually they may be used to power cars, buses, and may even
supply residential electricity.
Individual fuel cells produce relatively little electricity, so they are put
together in “stacks” to provide a useful amount of electricity. Currently, a
stack the size of the suitcase is sufficient to power a car.
Fuel cells require hydrogen and oxygen to operate. The oxygen can come from the
air, but hydrogen is a more difficult substance to handle. It is difficult to
store and transport, so fuel cells often use another device called a reformer to
convert other substances such as hydrocarbon or alcohol fuels into hydrogen.
Unfortunately, this conversion process cuts down on the efficiency of the fuel
cell.
It is hoped that fuel cells will eventually power cars, buses, and other devices
that depend on gasoline. Developing reformers that can use methane or propane
would make fuel cells highly practical. Some developers are also looking at a
way to store and transport hydrogen.
Fuel cells could also be used for devices like laptop computers, cell phones,
hearing aids, and other things that use traditional batteries for power. Fuel
cells would be easy to recharge -- simply add more of the fuel.
The technology is already available to supply household electricity in certain
areas. Using natural gas or propane reformers, up to 7 kW of electricity can be
generated. The system also produces heat that can be used to heat water and
provide at least some of the heating requirements of the house.
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