Fossil Fuel
Based Energy Access and Climate: a Double Clamp
by Evert Wesker
In my view humanity faces a double clamp which needs to be
resolved in the 21st century. On the one hand we are faced with a supply
constraint when considering easily accessible energy sources, being fossil
fuels (coal, oil and natural gas), while on the other hand we are faced
with a potential climate problem due to the rapid change of the
composition of the atmosphere due to human activities. In this article I
write down some thoughts on it.
Economic theory leading us astray
Classical economic theory tells us that prices of
commodities like metals and other mineable materials rise as they become
scarce. When, due to this, prices rise there will be a market-driven
impetus to dig deeper and access deposits previously thought too low grade
to be economically accessed. When taken to its limit one might say that
up to a certain limit of feasibility such materials cannot be
exhausted. They are only redistributed over the Planet and can be
reclaimed.
However, when applied to fossil fuels this concept is dead
wrong. When lignite, coal, oil, natural gas or Uranium are being used to
raise energy in some form, they no longer exist as an energy carrier. In
classic economic theory mass balances are taken into account in some way.
However, the second law of thermodynamics is not! Energy cannot be
recycled; energy is in the end just lost to a heat sink, being the
environment.
When looking at oil production in the 1950s, globally, oil
was produced at an energy cost of about 2% of the contained energy. By the
1990s this number had risen by a factor of 10; we were only able to
produce some 5 tons of oil for every ton consumed in its discovery and
production.
The first clamp: Supply
And it is here where the first clamp comes in. Discovering
oil, drilling, building production facilities, running these,
transportation through pipelines, shipping, refining and finally
distribution all require energy. As soon as the amount of energy required
to produce useful energy carriers from fossil sources exceeds the energy
contained in them it will be the "end of the line". The
"overhead" exceeds the net energy availability. The net gain is
negative. Even when the price of oil reached $1000 per barrel it wouldnt
make sense to produce it any more.
The annual discovery of oil rose from under 10 billion
barrels per year in 1910 to over 40 billion barrels per year in 1962.
After that year discoveries have fallen steadily to less than 10 billion
barrels per year. At the same time consumption, driven by a rapidly
growing world population and unsustainable consumption patterns in the
western world, increased steadily to its present rate of over 20 billion
barrels per year.
Is this problematic? One may say we have got coal as well
in ample quantities. However, open pit coal mining requires quite a bit of
energy (up to half of the contained energy in some cases). And where does
this energy come from? Exactly: oil products. A similar story can be told
about food production. The bread on your plate "used up" a five-
to tenfold of its own energy content from fossil fuel sources. And meat?
Multiply it by another factor of at least 5. So yes, it is highly
problematic.
The second clamp: Climate
The only way out of this constraint on the basis of a
fossil fuel economy is, apart from an expansion of natural gas or
coal, going for sources more difficult to access: deep offshore, oil
sands, coal to liquids. But they all require much more energy; their net
energy gain in terms of available energy in energy carriers (fuels) is
lower than in case of the "easy sources" like those in the
Middle East. So the amount of CO 2
emitted (unless one sequesters it again, at an energy cost) will
increase even further.
And then the second clamp comes in: the risk of a step
change in the climate on Earth, possibly including "nasty
surprises" like shifting precipitation zones turning cereal belts
into (semi) deserts.
It all leads me to the conclusion that a fossil fuel based
"business as usual" scenario is utterly unsustainable in the
longer run. Either the supply ceiling or the climate ceiling (or maybe
both!) will be hit at some point in time. A world with 9 billion people
and a per capita energy consumption of the order of 6 kW (a typical
contemporary western lifestyle) wont be reached.
Looking at economics in another way
Various studies concluded that a sustainable world would
require a maximum per capita energy consumption of something of the order
of 1.5 to 2 kW. Currently the world average is 2 kW.
In economics much attention is given to labour
productivity. It is easy to understand why, as it is the basis of
prosperity. However, if one looks at the aspect of sustainability, a
lopsided attention for labour productivity may lead one badly astray. If
oil is produced very effectively, but the energy consumption is higher
than the energy contained in it, the labour productivity of the oil
workers can be terrific, but the net effect as shown above is even
negative.
What needs to be taken into account, and will in my view
become much more important, is resource productivity. This implies that
economies need to cut back drastically their use of energy, their use of
materials and their transport needs. It will require an entirely different
way of thinking by economists. Labour productivity is not prime (although
a certain minimum level is required to enable sufficient wealth) but
resource productivity is of prime importance.
This presents a dilemma for Shell, as it is a ton/hr
business. Shell is a high labour productivity, and material and transport
intensive, business. Moreover, the current trend of bringing more
"difficult" oil resources into production is often at
loggerheads with a high resource efficiency.
One may think of a conversion of Shell from an oil company
into an energy company, in which the sustainable energy part slowly
replaces the fossil energy part. But that is much more easily said than
done. (In an appendix I list some energy sources and a very brief
description of their advantages and drawbacks. I also add a list of some
interesting reading material for those interested.)
Some concluding thoughts
With many essential resources depleted (oil, natural gas
and high grade ores), no civilization however competent will be able to
make the long climb from primitive conditions to high-level technology. In
that respect, the current human civilization endeavour may well be a
one-shot affair. I agree with the implicit message of Martin Rees in his
book "Our final century". If we fail, we would do so in an
irreversible way.
I end with a question to think about: What would be Shells
place in a resource productivity driven world?
Appendix: Alternative energy sources, advantages and
drawbacks.
First some "non-CO 2
non-sustainable" energy sources; their advantage is a much lower CO2
emission (the mining operations, extraction and transport of Uranium /
Thorium).
- Uranium reactors.
Light Water Reactors are the most common type
of nuclear reactor. In itself these are reasonably safe, although
mishaps are possible. However, the produced radioactive waste is a big
concern. Moreover, in order to use the fuel more efficiently,
reprocessing to extract Plutonium (Pu-239) is required. This opens the
possibility of (mis)use of this material for nuclear explosives.
Secondly, the production of mixed oxide elements is very costly. The
same objection, to an even higher degree, applies to Fast Breeder
Reactors. Finally, the Uranium mining operation to provide the initial
fuel is non-sustainable.
- Energy from Thorium.
This idea is some 10 years old. In an
accelerator, protons are collided with Thorium 232 nuclei to produce
Uranium 233 (beta decay via Protactinium). Uranium 233 is a fissile
isotope, so it can be used as a fuel. It is much more difficult to use
it as a resource for nuclear explosives than in the case of U-235 or
Pu-239. It also is safer, as Chernobyl-look-alike incidents are not
possible. This process could also be used to get rid of Plutonium and
other trans-Uranium waste. However, it probably is a very high cost
option.
Fusion options
- Deuterium + Tritium fusion.
In a magnetic confinement, a hot
plasma containing D and T is allowed to react to produce Helium and high
energy neutrons. Research in this field is ongoing and there are still
many problems to be solved. The "breeding" of Tritium is one
of them. One extra drawback is the fact that the neutrons produced can be
employed to breed Pu-239 from natural Uranium, thus opening doors
towards nuclear arms proliferation. And again, it probably is a very
high cost option.
- Borium + proton fission.
Another option is the reaction between
Borium-11 and a proton producing 3 Helium nuclei. No neutrons are
produced. On the other hand, the ignition temperature for this reaction
is higher than in case of D + T fusion, due to the much higher Coulomb
barrier. This option is being researched. It is probably one more very
high tech and very high cost option. It has some distinctive advantages
when compared to all the other nuclear options, so one could say that
the jury is still out in this case.
A non-conventional fossil option
- Methane hydrates.
The amount of methane enclosed in gas hydrates
is enormous a multitude of the total recoverable fossil fuel
resources. There are quite some issues which cast doubt on the
feasibility of exploiting gas hydrates. First of all it will still mean
CO 2
production although less than e.g. coal. Another much greater
concern is the controllability of its exploitation. How does one melt
the gas hydrates and subsequently catch the Methane without (massive)
leaks? Up to now no feasible scheme is available.
"Sustainable" options
- Solar energy.
The potential is enormous. The resource base is
120.000 TeraWatt. However, when one considers the required investments
for really massive scale photo-voltaics, one comes to the conclusion
that this is also a very long shot. The energy investment to build
photo-voltaic cells shouldnt be underestimated. For small scale it is
not very relevant, but if one thinks of scales in the order of many
GigaWatts it is a different story. Then this becomes a constraint. One
cannot say to all electricity users: "Please switch off all devices
for a year, because we now start the production of photo-voltaic cells
to cover your needs". The price is still an issue. Much work is
still needed to get it down to more acceptable levels. Solar heating is
a totally different story. That is quite cheap and totally feasible.
- Wind energy.
This is currently the cheapest form of sustainable
energy. At islands in trade wind areas it already can outcompete power
from diesel engine power stations. Although promising, it is not without
problems either. "Not in my back yard" is one of them. Also
migration routes of birds should be regarded. The maintenance of
off-shore installations is another issue.
For both wind and solar energy at some point in time (when
over 20% of the energy requirement is covered by them), a large scale
energy storage system is required. What this should look like is by no
means trivial. Should it be Hydrogen? Or pumped hydro? Or super
capacitors? The jury is still out here as well.
- Biomass.
Biomass looks good from a recycling point of view.
However, the space requirement is quite large. If one imagines a field
of Elephant Grass (3000 ton dry biomass per km² per year) the net energy
production on a continuous basis would be about 1 MW per km². So, for The
Netherlands about 100,000 km²
would be required. What should be looked upon are bio-waste streams
associated with agricultural production and turn the stuff into biofuels.
- Hydropower.
Small scale hydropower is benign and totally
feasible. E.g. some quite small villages high in the hills of Nepal were
provided with electricity in this way. On the other hand, large scale
hydropower is not environmentally benign. It disrupts river eco-systems
and often floods valuable land (an example is the Aswan Barrage in
Egypt).
From this very brief overview, one can see that turning
the world economy onto sustainable energy will be a difficult and long
job. There is no "cheap and easy" solution.
Secondly, it becomes clear once more that the resource
productivity must be increased dramatically to avert major problems in the
course of the coming century.
Background reading material
Books touching upon (the need for) sustainable development
- "Hubberts Peak, The Impending World Oil Shortage" by Kenneth
S. Deffeyes (Princeton University Press, 2001, ISBN 0-691-09086-6)
- "The Party is Over" by Richard Heinberg (New Society Pub.,
2003, ISBN 0865714827)
- "Our Final Century" by Martin Rees (Random House Group Ltd.,
2003, ISBN 0 434 008 095)
- "Sharing the Planet", Edited by Bob van der Zwaan and Arthur
Petersen Pugwash Netherlands (Eburon Academic Publishers, 2003, ISBN
90 5166 986 0)
Books about earth sciences and the evolution of life
- "New Views on an Old Planet" by Tjeerd H. van Andel
(Cambridge University Press, 1994, ISBN 0-521-44755-0)
- "Rare Earth, Why Complex Life is Uncommon in the Universe"
by Peter D. Ward and Donald Brownlee (Copernicus, 2000, ISBN
0-387-98701-0)
- "The Life and Death of Planet Earth" by Peter D. Ward and
Donald Brownlee (Times Books, 2002, ISBN 0-8050-6781-7)
- "Oxygen, The Molecule That Made the World" by Nick Lane
(Oxford University Press, 2002, ISBN 0-19-850803-4)
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