Message 05986 [Homepage] [Navigation]
Thread: oxenT05986 Message: 1/1 L0 [In index]
[First in Thread] [Last in Thread] [Date Next] [Date Prev]
[Next in Thread] [Prev in Thread] [Next Thread] [Prev Thread]

[ox-en] keimform.de: The Earth’s the Limit (2): Peak Oil—Peak Energy?



URL: http://www.keimform.de/2010/03/31/the-earths-the-limit-2/

   [[1]First part]

   During the last years, [2]humanity has consumed about 500 exajoules of
   energy per year (an exajoule is a million million megajoules, or 10^18
   joules). As usual, levels of energy consumption [3]vary strongly from
   country to country. While the average consumption per person is about 70
   GJ (gigajoules), the inhabitants of [4]Bangladesh, [5]Eritrea, and
   [6]Senegal use less than 10 GJ on average.

   At the other extreme, the inhabitants of the [7]United Arab Emirates and
   [8]Iceland use 450–500 GJ per year, while per-capita usage in the small
   emirate of [9]Qatar is a whopping 900 GJ. Germany uses about 180 GJ per
   person—more than twice the global average. Other Middle European
   countries are similar, while the United States and Canada use twice as
   much (330–350 GJ).

   Is it realistic that in the future, everybody will reach the consumption
   level of Germany or the USA, or even more? There are reasons for doubt,
   especially due to the source of the energy we use. More than 80 percent
   of the consumed energy result from burning [10]fossil fuels: oil (~36%),
   coal (~27%), and natural gas (~23%). This is problematic for two
   reasons: (1) fossil fuels are non-renewable sources of energy that will
   be exhausted sooner or later. (2) The burning of fossil fuels is the
   main source of [11]global warming, the human-made climate change that
   threatens humanity and other species with dramatic and often fatal
   consequences.

Peak Oil, Peak Gas, Peak Coal

   If consumptions of oil continues at the current level, we will [12]run
   out of oil in approximately 43 years. Estimates for the remaining gas
   and coal reserves are more varied. According to the estimates of the US
   Department of Energy (cited in the same source), gas will last for 61
   years and coal for 148 years. Other estimates are somewhat more
   optimistic, but in any case it is clear that none of the fossil fuels
   will last forever.

   In reality, of course, future consumption levels won’t remain constant
   until reserves suddenly “run out”. On the one hand, consumption is
   likely to increase due to economic growth and due to the growth of human
   population (if world population increases from 6.7 billion to 9 billion
   in 2050, that alone would mean an 35% increase in the usage of fossil
   fuels, even if the average usage per person remains constant). On the
   other hand, easily accessible reserves are usually exploited first. At
   some point worldwide extraction of petroleum will start to decline,
   after accessible reserves have been exhausted and can only slowly be
   replaced by reserves that are more expensive and energy-consumptive to
   exploit. This point is known as [13]peak oil.

   In the US, the [14]peak of oil extraction was reached in the the early
   1970s; since then, oil extraction has gradually declined. It seems quite
   certain that the global peak of oil extraction is not very far away.
   [15]Most analysts seem to suppose that peak oil will occur sometime
   before 2020; some believe that it already occurred in about 2007, before
   the start of the current economic crisis (oil extraction declined since
   then due to shrinking demand).

   When the oil supply starts to decline while demand is still stable or
   (more likely) growing, it will not only mean higher oil prices and
   possibly violent struggles for the distribution of the remaining
   resources. It will also mean that the resulting supply gap will be
   partially filled by a faster exhaustion of gas and coal. Most estimates
   therefore conclude that peak gas and peak coal will occur at most a few
   decades after peak oil, probably between 2020–40 for [16]peak gas and
   before 2050 for [17]peak coal. Since the energy gained from fossil fuels
   will thus start to shrink in the near future, humanity will have to
   learn to survive with less energy or to rely much more strongly on
   [18]renewable energy—or more realistically, both. (Nuclear power is
   sometimes advertised as another option, but it can’t fill the gap since
   it’s not really renewable and [19]suffers its own peak; also nuclear
   power would clearly be unsuitable for a decentralized peer economy for
   various reasons.)

   This will be quite a challenge, since only about 1.6% of the current
   energy comes from the renewable energy sources that have a large
   untapped potential—mainly [20]solar energy (1.3%) and [21]wind power
   (0.3%). There are other sources of renewable energy that currently play
   a more important rule, namely [22]biomass and biofuels (13.5%) and
   [23]water power (3.3%), but these have already reached a high share of
   their maximum capacity—they lack the theoretical potential to yield
   enough energy to replace today’s non-renewable energy sources. Solar
   power currently mainly comes in the form of [24]solar thermal energy
   used for heating; the contributions of solar [25]photovoltaics are
   negligible. (These and the following figures are from the [26]Renewables
   2007 Global Status Report, p. 9, 12, 38, unless another source is
   specified.)

   If humanity wants to continue (or even increase) its current levels of
   energy consumption, it will have to increase the energy produced from
   solar and wind power by factor 50 or more before fossil fuels run out.

Limited Renewable Sources

   There are some other renewable sources of energy, but their potential is
   limited. About 3.3% of the current energy mix comes from [27]hydropower,
   but the International Hydropower Association [28]estimates (PDF) that
   one third of the realistic global potential of water power has already
   been developed. If this estimate is true, it means that water power will
   never be able to contribute more than about 10% to the global energy
   mix.

   [29]Biomass plays an important role as energy source, mainly in the form
   of so-called traditional biomass: wood, charcoal (made from wood), and
   agricultural waste used for heating and cooking, especially in Africa
   and Asia. These “traditional” uses comprise about 13% of the global
   energy mix, while nontraditional uses ([30]biofuels and electricity made
   from biomass) comprise about 0.5%.

   But the Earth’s surface area that could be used for biomass production
   is limited. [31]According to the FAO (UN Food and Agriculture
   Organization), energy gained from wood accounts for 7–9% of the energy
   consumed worldwide (up to 80% in some developing countries), but wood
   fuels already account for 60% of the global consumption of forest
   products. [32]Forests cover about four billion hectares—30% of total
   land area of the Earth. 34% of these forests are primarily used for the
   production of wood and other forestry products; more than half of all
   forests are used for productive purposes either primarily or in
   combination with other functions such as recreation or biodiversity
   conservation. A large part of the rest (36% of all forest area) are
   primary forests largely untouched by human activity—which should better
   remain so, since wilderness areas are important for biodiversity and for
   keeping Earth a planet that is not totally subjected to utility concerns
   ([33]Global Forest Resources Assessment 2005, p. 4, 6).

   So the area available for biomass production is already largely used for
   this purpose, since the 70% of land surface that aren’t covered by
   forests are usually needed for human habitation or agriculture (except
   where they are deserts or natural reserves). Even if the energy
   extracted from biomass was doubled, it wouldn’t account for more than
   one quarter of humanity’s current energy needs, and it is hard to see
   how more than that could be achieved. Modern biofuels don’t seem to do
   better than traditional fuel wood regarding their space
   requirements—ethanol and other biofuels already consume 17% of the
   world’s grain harvest (Richard Heinberg, [34]Searching for a Miracle, p.
   48), but contribute only 0.3% of the energy produced. And biofuels have
   rightly [35]come under criticism for absorbing grain that could
   otherwise be used for human consumption and contributing to raising food
   prices during the last years.

   [36]Geothermal power is another source of energy that is marginal as of
   today but might play a more important role in the future. It utilizes
   heat stored below the surface of the Earth for heating or for generating
   electricity. Geothermal energy comes in two flavors: there are
   [37]geothermal heat pumps, which can be an efficient and decentralized
   approach to heating (or cooling) buildings. And there are [38]geothermal
   plants that generate electricity. This latter flavor is a large-scale
   technology that interferes much more heavily with the Earth;
   construction of geothermal plants has [39]triggered earthquakes (e.g. in
   Basel, Switzerland) and caused slow deformation of the land surrounding
   the plant (e.g. in the German Black Forest).

   This makes geothermal plants problematic, especially for a peer
   production–based society that favors decentralized and unobtrusive
   technologies. In any case, the electricity generation potential of
   geothermics is limited—[40]estimates vary wildly, ranging from 35 to
   2000 GW. Even the highest estimate—2000 GW—, which is almost certainly
   strongly exaggerated, would correspond to only 13% of the current
   worldwide energy demand; space heating (which could partially be
   satisfied though geothermal heat pumps) makes up another [41]less than
   16% of the total energy demand. Thus the contributions of geothermal
   energy are necessarily limited as well.

   So, while water power, biomass, and geothermal heat will be able to
   contribute to a global renewable energy mix, they hardly will be able to
   make up for the energy currently extracted from fossil fuels. The
   biggest part will have to come from solar and wind energy.

   [To be continued…]

References

   1. http://www.keimform.de/2010/02/09/the-earths-the-limit-1/
   2. http://en.wikipedia.org/wiki/World_energy_resources_and_consumption
   3.
http://en.wikipedia.org/wiki/List_of_countries_by_energy_consumption_per_capita
   4. http://en.wikipedia.org/wiki/Bangladesh
   5. http://en.wikipedia.org/wiki/Eritrea
   6. http://en.wikipedia.org/wiki/Senegal
   7. http://en.wikipedia.org/wiki/United_Arab_Emirates
   8. http://en.wikipedia.org/wiki/Iceland
   9. http://en.wikipedia.org/wiki/Qatar
  10. http://en.wikipedia.org/wiki/Fossil_fuel
  11. http://en.wikipedia.org/wiki/Global_warming
  12. http://en.wikipedia.org/wiki/Fossil_fuel#Levels_and_flows
  13. http://en.wikipedia.org/wiki/Peak_oil
  14. http://en.wikipedia.org/wiki/Hubbert_peak_theory
  15. http://en.wikipedia.org/wiki/Peak_oil#Timing_of_peak_oil
  16. http://en.wikipedia.org/wiki/Peak_gas#World_peak_gas
  17. http://en.wikipedia.org/wiki/Peak_coal
  18. http://en.wikipedia.org/wiki/Renewable_energy
  19. http://en.wikipedia.org/wiki/Peak_uranium
  20. http://en.wikipedia.org/wiki/Solar_power
  21. http://en.wikipedia.org/wiki/Wind_power
  22. http://en.wikipedia.org/wiki/Biomass
  23. http://en.wikipedia.org/wiki/Hydropower
  24. http://en.wikipedia.org/wiki/Solar_thermal_energy
  25. http://en.wikipedia.org/wiki/Photovoltaics
  26. http://www.ren21.net/pdf/RE2007_Global_Status_Report.pdf
  27. http://en.wikipedia.org/wiki/Hydropower
  28. http://hydropower.org/downloads/F8%20Hydropower%20and%20Sustainability.pdf
  29. http://en.wikipedia.org/wiki/Biomass
  30. http://en.wikipedia.org/wiki/Biofuel
  31. http://www.fao.org/forestry/28816/en/
  32. http://www.fao.org/forestry/28808/en/
  33.
http://www.fao.org/forestry/foris/data/fra2005/kf/common/GlobalForestA4-ENsmall.pdf
  34. http://www.postcarbon.org/report/44377-searching-for-a-miracle
  35. http://en.wikipedia.org/wiki/Food_vs._fuel
  36. http://en.wikipedia.org/wiki/Geothermal_power
  37. http://en.wikipedia.org/wiki/Geothermal_heat_pump
  38. http://en.wikipedia.org/wiki/Geothermal_electricity
  39. http://en.wikipedia.org/wiki/Geothermal_power#Environmental_impact
  40. http://en.wikipedia.org/wiki/Geothermal_power#Resources
  41.
http://en.wikipedia.org/wiki/World_energy_resources_and_consumption#By_sector

-- 
|------- Dr. Christian Siefkes ------- christian siefkes.net -------
| Homepage: http://www.siefkes.net/ | Blog: http://www.keimform.de/
|    Peer Production Everywhere:       http://peerconomy.org/wiki/
|---------------------------------- OpenPGP Key ID: 0x346452D8 --
When the great lord passes the wise peasant bows deeply and silently farts.
        -- Ethiopian proverb



Thread: oxenT05986 Message: 1/1 L0 [In index]
Message 05986 [Homepage] [Navigation]