Hydrogen Sources - Hydrogen and Fuel Cells: Advances in Transportation and Power - page 125

ducing 1-kg of hydrogen by electrolysis could generate about 70 pounds
of CO 2 . A gallon of gasoline and a kilogram of hydrogen have almost the
same energy, and even allowing for the improved efficiency of fuel cell ve-
hicles, (more mpg or mpkg) producing hydrogen from electrolysis could
produce more greenhouse gases if fossil fuels are used. These economic
and environmental issues can make it difficult to pursue the generation of
significant quantities of hydrogen from the present U.S. electric grid in the
near future.
Hydrogen could be generated from renewable electricity, but the re-
newable system most suitable for local generation, solar photovoltaics, is
expensive because of the cost of photovoltaic panels. The least expensive
form of renewable energy, wind power, is only about one tenth of 1% of all
U.S. generation, although that figure is rising.
Generating hydrogen from electrolysis powered by renewables is
viewed by some as a good use of that power for economic and environ-
mental reasons. But, the United States would need abundant low-cost
renewable generation before it could divert a substantial fraction to the
production of hydrogen. If forecourt hydrogen generation from solar
photovoltaics becomes practical in the first half of the century, it could
supply enough hydrogen to the growing amount of fuel cell cars and gen-
erating systems while hydrogen generated from the vast wind resources
of the Midwest would need large infrastructure costs for delivering it to
other parts of the country. A large steam reformer plant could supply 1
million cars with hydrogen.
While we may be close to cost-effective fuel cell prototypes, there
must be the infrastructure to support them. Another problem that we are
getting closer to is fuel storage and the high-density storage of hydrogen
gas.
Methanol would allow a transitional phase where some fuel cell ve-
hicles use methanol, which is relatively simple to reform and would not
present too big a change from our current system. However, methanol is
toxic and very corrosive. Gas stations would need to be retrofitted to oper-
ate with it (new fuel tanks and fuel lines.) But, many gas station tanks are
already methanol- compliant.
Politics plays a role in which fuel is used. Ethanol, for example, can
be made from corn and is popular in the Midwest.
Fuel cells are overdue in becoming a major part of our energy future.
Then, one in three or even one in two of the cars on the road may be fuel
cell vehicles. There are obstacles and challenges to that happening, but