The Energy Evolution - Hydrogen and Fuel Cells: Advances in Transportation and Power - page 21

HYDROGEN AND GLOBAL WARMING
Hydrogen fuel cells do not emit carbon dioxide, but extracting hy-
drogen from natural gas, gasoline or other products requires energy and
involves other by-products. Obtaining hydrogen from water through elec-
trolysis consumes large amounts of electrical power. If that power comes
from plants burning fossil fuels, the end product can be clean hydrogen,
but the process used to obtain it can be polluting.
After the hydrogen is extracted, it must be compressed and trans-
ported, if this equipment operates on fossil fuels, they will produce CO 2 .
Running an engine with hydrogen extracted from natural gas or water
could produce a net increase of CO 2 in the atmosphere.
FUEL CELL APPLICATIONS
Fuel cells seem like an energy user's dream: an efficient, combus-
tion-less virtually pollution-free power source, capable of being sited in
downtown urban areas or in remote regions, that runs almost silently and
has few moving parts. Based on an electrochemical process discovered
more than 150 years ago, fuel cells supplied electric power for spacecraft
in the 1960s. Today they are being used in more and more distributed gen-
eration applications to provide on-site power and waste heat in some cas-
es for military bases, banks, police stations and office buildings from natu-
ral gas.
Fuel cells can also convert the energy in waste gases from water
treatment plants to electricity. In the future, fuel cells could be propelling
aircraft, automobiles and allowing homeowners to generate electricity in
their basements or backyards.
While fuel cells operate much like a battery, using electrodes in an
electrolyte to generate electricity, they do not lose their charge as long as
there is a constant source of fuel.
Fuel cells to generate electricity are being produced by companies
such as Plug Power, UTC, FuelCell Energy and Ballard Power Systems.
Most of these are stationary fuel cell generators. Plug Power has hundreds
of systems in the U.S. including the first fuel-cell-powered McDonald's.
The installed fuel cells have a peak generating capacity of about 100 mega-
watts, which is only 0.01% of the nearly one million megawatts of total
U.S. generating capacity.