Hydrogen sources for fuel cells

Date: Fri, 14 Mar 2003 13:44:04 -0400 (AST)
From: Larry Hughes <lhughes2@dal.ca>
To: Sustainable Maritimes <sust-mar@chebucto.ns.ca>
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The fuel cell has been promoted for the past few decades as a solution to
many of our environmental problems, especially in the transportation
sector.  Automobile manufacturers have been promoters of fuel cells since
the only greenhouse gas they emit is water (the fact that problems such as
urban sprawl, congestion, and traffic fatalities will not be solved by the
fuel cell are conveniently overlooked).
 
Most fuel cells take hydrogen and generate electricity that can be used to
power electric motors.  Although hydrogen exists in nature, it is not
found in sufficient quantities (that is, it can't be extracted like coal
or oil), meaning that hydrogen must be made from other sources, notably:
 
* The 'reformation' of fossil-based fuels such as gasoline or natural gas,
extracting the hydrogen.  Attractive to many, since a network of service
stations already exist in the developed world, allowing hydrogen to be
made on location from fossil fuels.
 
* The 'electrolysis' of water, passing a current through water, breaking
the hydrogen-oxygen bonds, releasing the hydrogen.  Attractive to many,
since most of the developed world has access to electricity, allowing
hydrogen to be made at an electrical outlet.

* Biological processes, under certain conditions, some types of bacteria
will produce hydrogen.  This has great potential, but it is still too
early to judge whether hydrogen yields can meet our demands.
 
Of the two approaches that could be implemented now (i.e., reformation and
electrolysis), many fuel cell advocates push for the electrolysis of
water, since the electricity used to produce the hydrogen need not come
from fossil fuels.
 
This raises the question -- if not from fossil fuels, where will the
electricity come from?  This is an important question to answer, since the
final cost of the hydrogen will depend upon the cost of the fuel used to
generate the electricity.
 
In Iceland, geothermal energy is to be used to generate electricity for
electrolysis.  This makes sense since there are no fuel costs associated
with generating the electricity (the geothermal energy is free).
 
Some advocates of wind energy have promoted the use of hydrogen, because
wind has zero fuel costs.  However, the cost of wind-generated electricity
is presently quite high and, more importantly, its intermittent nature can
play havoc with the electrolysis equipment.
 
Are there other alternatives? 
 
In the 14 March 2003 edition of the Globe and Mail, fuel cell advocate
Geoffrey Ballard has a lengthy article explaining why we need to switch
over to fuel cells and hydrogen for our transportation system.  He
recommends using electrolysis with electricity generated by the ACR or the
advanced Candu reactor.

Larry Hughes, PhD
Professor
Department of Electrical and Computer Engineering
Dalhousie University
Halifax, Nova Scotia, B3J 2X4, Canada

v: 902.494.3950
f: 902.422.7535
e: larry.hughes@dal.ca
u: http://www.dal.ca/~lhughes2



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