Let's assume H2 is a good way to fuel transportation and run other
engines that cannot have a power cord. Let's assume it might even be a
good way to heat homes rather than natural gas (either because natural
gas gets too scarce and expensive, or because of the CO2 problem when
burning natural gas. I know these assumptions might not be true... but
just go with it for a minute.
Why would we want to use solar or wind power to make the electricity to
make the hydrogen by electrolysis? Because these sources of electricity
are clean (including no CO2) and "renewable," and conversion to hydrogen
is a possible way to store the energy during dark or low wind
conditions. When used, the combustion of the hydrogen is fairly clean.
Why would we want to use nuclear power to make the electricity to make
the hydrogen? To the extent that we have decided to use nuclear power
in general, then if sufficient generation capability exists, we might as
well make hydrogen this way (for those applications that cannot use a
power cord). Plus, hydrogen can be made during off-peak times.
Why would we want to use natural gas to make electricity to make the
hydrogen? I cannot think of good reasons. I do not believe we should
be using natural gas to make electricity at all. Natural gas is
currently too valuable as a home heating fuel and as a feedstock for
various chemical industries. Plus, using hydrogen gas in cars and homes
does not offer any benefit over using natural gas for those
applications. That is, there is no benefit to counteract the
inefficiencies involved in making the electricity with natural gas and
using that to make hydrogen. See next paragraph for the benefit of H2
over coal and oil.
Why would we want to use coal or oil to make the electricity to make the
hydrogen? As long as coal and oil exist at a reasonable price, the
reason to use them to make hydrogen (rather than burning coal in our
homes and burning gasoline in our cars) is because it turns many
difficult-to-regulate sources of pollution into fewer more controllable
sources of pollution. We can design and maintain a coal-fired power
plant to run more cleanly than designing and maintaining a million
gasoline-powered automobiles. Plus, hydrogen can be made during off
peak times.
Conclusion... I believe that if we were to agree that H2 distribution
and use is a reasonable thing, independent of how the hydrogen is
produced, then we could argue that solar, wind, nuclear, coal/oil would
each have some merit as a way to produce electricity to produce
hydrogen. However, I do not think natural gas is a good way to generate
electricity at all because natural gas reserves should be maintained as
long as possible for uses other than electricity generation.
Michael D. Edmiston, Ph.D.
Professor of Chemistry and Physics
Bluffton College
Bluffton, OH 45817
(419)-358-3270
edmiston@bluffton.edu