[Grovenet] FYI, from this week's E-Skeptic

[Gregory Gritton]

Hi all,

Many people place a lot of hope in the "Hydrogen economy"
without realizing what it really is.  The article does well
to point out that Hydrogen is an energy carrier, not a source,
and that it isn't a very efficient energy carrier.

However, while the general message of the article makes sense,
it does contain a number of irrelevancies and at least one
inaccuracy that make things seem even worse than they are.

The inaccuracy is simple.  The article mentions 220,000 miles
of natural gas pipelines costing $1 million/mile.
It gives a figure of $200 trillion or more for duplicating
that for hydrogen.  But, if you do they math, they are off
by 3 orders of magnitude.  The cost would be $200 billion.
(Still a huge sum, but not absolutely impossible.)
This is the only error I noticed due to the fact that it
was so glaring, but if there was this one, there may be others.

The irrelevancies are a little trickier.

One common way to rate energy usage is on efficiency.
This works well for a single energy source.  For example,
it is valid to compare the efficiency for propelling a car
of burning oil in an internal combustion engine, like we
do now, to burning oil in a power plant to generate
electricity and propelling a car with the electricity,
or producing hydrogen from oil and propelling the car
with hydrogen.

Efficiency comparisons work less well when comparing
different energy sources.  If the sources are fuels
like oil or coal, there is some sense, since both could
be burned in similar power plants, that ought to have
comparable thermal efficiencies.  But, comparing the
efficiency of burning oil to extracting the energy from
the wind or the sun is nonsense.  The fact that wind
turbines are only 30-40% efficient at extracting energy
from the wind has no relationship too the efficiency
of burning oil, nor does the 9% efficiency of solar cells.
Oil is ultimately derived from solar, so one might as
well compare the efficiency of creating oil from the sun,
vs. solar panels.  Measured in that way, the solar panels
are quite a bit more efficient.

While the article exaggerates some of the problems,
one theme it doesn't discuss much, that it could have,
is the underlying assumption that we will all continue
to drive cars in the same way we do now as world oil
production levels off and then declines.  Switching
to electric vehicles (or hydrogen powered ones) would
require a massive increase in our electrical generation
capacity.

An alternative might be improved public transportation
networks as exist in Europe, where thousands of miles
of electrified railroads exist.  Even after accounting
for electrical generation losses, European railroads
use less than 1/2 the energy per passenger mail than our
cars do.  (Raw energy usage is less than 1/6th.)

Developing such a network would require both a significant
expenditure as well as revising regulations that currently
prohibit light weight trains in the US.  Even so, it would
be far smarter than to try to fight over the ever decreasing
oil reserves that exist in the world, or to pin all our
hopes on a mythical hydrogen economy.

Sincerely,

Greg Gritton