New Energy Source
In the near future, millions of homes and businesses
may get their electricity from small on-site generators
that create no pollution and need no power lines. Fuel
cells -- the electrochemical generators now used to run
spacecraft -- can revolutionize the way we get our
electricity, especially in remote areas.
"Fuel cells have the potential to change the way
we look at electricity in fundamental ways," said
Bob Rose of the U.S. Fuel Cell Council, a Washington,
D.C.-based trade association. "Think of it: Instead
of depending on the grid for power, you can make your
own and use the grid as a backup."
Unlike batteries, which consume themselves, fuel cells
are almost endlessly rechargeable as long as there is a
source of hydrogen. "There is enormous potential for
residential fuel cells worldwide," said Peter Bos,
director of the Fuel Cell Commercialization Group, a
California association of U.S. and Canadian utilities.
Fuel cells consist of an electrolyte sandwiched between
two electrodes. Oxygen from air passes over one electrode
and hydrogen over the other, creating an electrochemical
reaction that produces electricity, water and heat. Fuel
cells have been around since 1839, but it wasn't until the
1950s and 1960s that scientists began using them to power
space craft.
There are five types of fuel cells, categorized by the
type of electrolyte they use: proton exchange membrane;
phosphoric acid; alkaline; molten carbonate, and solid
oxide. Each type has its own operating characteristics,
such as size and operating temperature, that make it
useful in specific applications ranging from large power
plants to transportation to low-wattage remote sites.
High initial costs and relatively short lives have been
the major obstacles to widespread use of fuel cells, a
polution-free way of generating power. As unit costs
decrease and quality improves, electricity from fuel
cells will be available for the same price or less than
what traditional utilities charge, Bos said. "If you have
a choice of a small, independent source of electricity,
guess which one you will choose?" he asked.
