I read part of a book recently (a free sample on Kindle!) titled "The
Long Emergency" by James Kunstler. Based on the first chapter and the
reviews, I gather the author thinks that alternative energy such as
wind or solar will not suffice to maintain modern, high-tech, high
energy civilization in North America. He thinks that declining oil
production from resource exhaustion will cause widespread social
trauma and that existing technology cannot fix the problem.
These numbers for solar thermal plants from RenewableEnergyWorld give
the lie to that assertion. These are actual numbers for existing
plants, and engineering projection numbers for upcoming plants. Not
pie-in-the-sky extrapolations for future technology. Anyway, very roughly:
The Riverside Solar Millennium 986 MW trough solar thermal takes up 2091 ha
U.S. summer peak generation capacity in 2008 was 752,470 MW
<http://www.eia.doe.gov/cneaf/electricity/epa/epa_sum.html>http://www.eia.doe.gov/cneaf/electricity/epa/epa_sum.html
~20% of U.S. capacity is met with ~100,000 MW of nuclear power.
(100,000 MW*5 equals only 500,000 MW instead of 752,470 MW because
nukes are turned on 24/7 for baseline generation).
Anyway, you wouldn't do this, but if you wanted 752,470 MW of
capacity in broad daylight, and 0 MW capacity at night, you could
supply it with 763 solar thermal plants like the Solar Millennium.
This would take up 1.6 million ha. That's 15,958 square kilometers,
or 6,161 square miles.
Again, it would not make sense to do this, but you could fit the
whole kit-and-caboodle into a square 126 km to a side (square root of
15,958) or 78 miles in the middle of the Mojave desert. The Mojave
Desert is 25,000 square miles, so this would take up about a quarter
of it. There are many other places in the U.S. and of course North
Africa where you can drive 78 miles and see only unpopulated land
which could be used for this purpose. Of course it would have an
effect on the wildlife, but that effect would not necessary be
deleterious. Burning coal or building dams is pretty much 100% deleterious.
6,161 square miles is 0.2% of U.S. land area.
This would be a tremendous project, but spread over 20 or 30 years
the cost would not be all that high. It would be far cheaper than
building 752,470 MW of nukes.
The point is, you could generate nearly as much electricity as we
presently generate with a relatively modest use of land, using
existing technology. Of course this would not actually suffice to
supply all electricity, since it goes off at night. I only used these
number to show a ballpark estimate of what could be done. In real
life, to end the use of fossil fuel, you would use some of this
solar-thermal capacity to produce liquid fuel for plug-in hybrid
vehicles. These require far less gasoline than conventional cars. GM
estimates that for the average driver, the upcoming Volt will get
"230 MPG for the average city driver over time assuming nightly full
recharges."
<http://gm-volt.com/chevy-volt-faqs/>http://gm-volt.com/chevy-volt-faqs/
Since the average U.S. car now gets 22 MPG, this would reduce our oil
consumption by a factor of 5 or 10. It is not a factor of 10 after
you take into account fuel used in aviation and by truck which would
not benefit as much from plug-in hybrid designs, but anyway, it is
more than enough to bankrupt OPEC and bring the fossil fuel era to a
quick end. I do not think it would cost a huge amount to synthesize
10% or 20% of our present petroleum. Bear in mind that in this
scenario all of the other advanced countries in the world, plus
China, would also be adapting plug-in hybrid technology, as well as
solar thermal, wind and so on. China is a technologically advanced
country, fully capable of doing projects like this, even though per
capita income is still low. In other words, the whole world would
soon reduce oil consumption by a large factor, stretching out
supplies and reducing the threat of global warming.
Needless to say, improved batteries, HTSC transmission, and other
not-yet-invented technology would make it easier to implement massive
solar thermal plants of this nature. Also needless to say, you would
not actually throw away the existing stock of nuclear, natural gas or
even coal plants, and in many northern states you would build wind
turbine farms instead. So we would not actually need 0.2% of the land.
Getting back to the book "The Long Emergency" the author makes some
egregious mistakes, such as claiming that we could not have nuclear
plants without fossil fuel to operate uranium mining equipment and
the like. He does not seem to realize that a nuclear plant can be
used to synthesize liquid fuel for uranium mining equipment. Even if
that was substantially more expensive than naturally occurring
gasoline, it could be done. The energy overhead would be modest. That
is to say, the ratio of total energy output of the nuclear plant
compared to the energy needed to synthesize the fuel would be small.
I expect that over the life of a plant, a few months devoted to
liquid fuel production would be enough to build the next plant and
mine the uranium. I do not have the exact numbers handy but I have
looked up the amount of energy it takes to mine and manufacture
uranium fuel compared to the energy produced by the fuel, and the
numbers are quite favorable compared to, say, gasoline, which has 10%
to 20% energy overhead these days (depending on the grade of the oil,
where it is extracted, where it is transported to, and other factors).
In actual practice, it would probably be better to design some
nuclear plants devoted to liquid fuel production, or to produce it
with solar thermal plants, rather than using general purpose electric
power generation plants.
The point of all this is that alternative energy can supply all of
our needs at a reasonable cost. Probably more than we pay now,
although it might be cheaper later on. Naturally, cold fusion would
be far better, cheaper, and it could be implemented faster, but
existing conventional sources would suffice. The dire scenarios
described in "The Long Emergency" may come to pass, but if they do,
they will be caused by politics, economics, greed or stupidity, or
perhaps by global warming. They will not be caused by inherent limits
to technology or shortages in fossil fuel. Shortages are inevitable
but they need not be anything more than an expensive irritation, like
the decaying stock of water and sewage pipes in Atlanta. It is
costing a lot to fix them but no one doubts that we can handle the job.
Arthur Clarke summarized the situation eloquently in "Profiles of the Future:"
"The heavy hydrogen in the seas can drive all our machines, heat all
our cities, for as far ahead as we can imagine. If, as is perfectly
possible, we are short of energy two generations from now, it will be
through our own incompetence. We will be like Stone Age men freezing
to death on top of a coal bed.
. . . there need never be any permanent shortage of raw materials.
Yet Sir George Darwin's prediction that ours would be a golden age
compared with the aeons of poverty to follow, may well be perfectly
correct. In this inconceivably enormous universe, we can never run
out of energy or matter. But we can all too easily run out of brains."
- Jed
