Hydrogen Sources - Hydrogen and Fuel Cells: Advances in Transportation and Power - page 134

with an 80-miles-per-gallon fuel cell car using untaxed hydrogen. When
both vehicles get 80 miles to the gallon and neither fuel is taxed, then
hydrogen can cost 2 to 3 times more per mile. But, generating hydrogen
through renewable sources could reduce these costs in the future.
A Princeton study of the Los Angeles area focused on the potential
for solar photovoltaic plants in the desert areas east of the city. The study
concluded that enough hydrogen could be produced with solar power in
an area of 21 square miles to fuel one million fuel cell cars.
The wind site areas at Tehachapi Pass and San Gorgonio are believed
to have a similar potential. Geothermal power would be another renew-
able source. A problem in generating hydrogen this way is the long-distance
pipelines required since the gas is leaky compared to other products.
NATURAL GAS AND ELECTROLYSIS
Natural gas is a major feedstock for near-term hydrogen production
in the U.S. Natural gas is a non-renewable resource, and hydrogen pro-
duction from reforming natural gas would result in substantial carbon di-
oxide emissions. Great supplies of natural gas are found in sensitive lo-
cations and unstable parts of the world, along with petroleum. To power
40% of the U.S. auto fleet with hydrogen from natural gas in 2025, using
high efficiency fuel cells, would require a 1/3 more natural gas using pro-
jected 2025 levels. Natural gas is already in heavy demand as a clean fossil
fuel for power plants, so alternative sources of hydrogen production are
needed. Unless global warming emissions are stored underground, natu-
ral gas use will continue to contribute to global warming. But, natural gas
could act as a transition fuel.
Electrolysis using renewable electricity, wind, water or photovoltaics,
could produce a domestic, non-polluting hydrogen transportation fuel.
But, hydrogen produced today by this method can be more than 3 times
the cost of an equivalent gallon of gasoline. If the electricity is supplied
from the present electrical grid, which is more than 50% coal-fueled, it
would generate even larger amounts of carbon emissions than the natural
gas process.
In order for hydrogen fuel cell vehicles to reduce global warming gas-
es, the electrolysis process will need to become more efficient, and the elec-
tric power will need to be produced from a higher percentage of low-to
zero-carbon sources (renewables or coal with carbon capture and storage).