WORLD ENERGY RESOURCES AND CONSUMPTION

To make it easier to compare the numbers, this article uses SI units and prefixes and measures ''energy rate'' (or power) in watts (W) and ''amounts of energy'' in joules (J).
In 2004, the 'worldwide energy consumption' of the human race was 15 TW (= 1.5 x 10¹³ W) with 86.5% from burning fossil fuels. World Consumption of Primary Energy by Energy Type and Selected Country Groups, 1980-2004 This is equivalent to 0.5 ZJ (= 5 x 10²⁰ J) per year. As shown by the difference between the first two images in this article, there is at least 10% uncertainty in the world's energy consumption. Not all of the world's economies track their energy consumption with the same rigor and the exact energy content of a barrel of oil or a ton of coal will vary with their quality.
The remaining 'worldwide energy resources' are large, with the remaining fossil fuels totaling an estimated 0.4 YJ (1 YJ = 10²⁴J) and the available nuclear fuel such as uranium exceeding 2.5 YJ. Fossil fuel range from 0.6-3 YJ if estimates of reserves of methane clathrates are accurate and become technically extactable. Mostly thanks to the Sun, the world also has a renewable usable energy flux that exceeds 120 PW (8,000 times 2004 total usage), or 3.8 YJ/yr, dwarfing all non-renewable resources. However due to the small angle the earth's outline makes with the sun the earth only captures a very small fraction of the sun's total energy outuput.

Contents

Consumption

Fossil fuels

Nuclear power

Renewable energy

Hydropower

Biomass and biofuels

Wind power

Solar power

Geothermal

By country

By sector

Resources

Fossil fuel

Coal

Oil

Sustainability

Nuclear power

Nuclear fission

Nuclear fusion

Renewable resources

Solar energy

Wind power

Wave and tidal power

Geothermal

Alternative energy paths

See also

Footnotes

References

External links

Consumption

Since the advent of the industrial revolution, the worldwide energy consumption has been growing steadily. In 1890 the consumption of fossil fuels roughly equaled the amount of biomass fuel burned by households and industry. In 1900, global energy consumption equaled 0.7 TW(=10¹² Watt.)^[6]

Fossil fuels

The twentieth century saw a rapid twentyfold increase in the use of fossil fuels. Between 1980 and 2004, the worldwide annual growth rate was 2%. According to the US Energy Information Administration's 2006 estimate, the estimated 15TW total energy consumption of 2004 was divided as follows, with fossil fuels supplying 86% of the world's energy:

'Fuel type'	'Power in TW'	'Energy/year in EJ'
Oil	5.6	180
Gas	3.5	110
Coal	3.8	120
Hydroelectric	0.9	30
Nuclear	0.9	30
Geothermal, wind, solar, wood	0.13	4
'Total'	'15'	'471'

Coal fueled the industrial revolution in the 18^th and 19^th century. With the advent of the automobile, airplanes and the spreading use of electricity, oil became the dominant fuel during the twentieth century. The growth of oil as the largest fossil fuel was further enabled by steadily dropping prices from 1920 until 1973. After the oil shocks of 1973 and 1979, during which the price of oil increased from 5 to 45 US dollars per barrel, there was a shift away from oil.^[7] Coal and nuclear became the fuels of choice for electricity generation and conservation measures increased energy efficiency. In the US the average car more than doubled the number of miles per gallon. Japan, who bore the brunt of the oil shocks, made spectacular improvements and now has the highest energy efficiency in the world. Over the last forty years, the use of fossil fuels has continued to grow and their share of the energy supply has increased. In the last three years, coal has become the fastest growing fossil fuel.^[8], however without carbon capture and many other controls on air pollution, increased use of coal is a major setback to quality of life. Photovoltaics are rapidly becoming available to replace fossil fuels as the dominant energy source. Note the earlier comparison of availability, the total resources of all fossil fuels amount to about 0.4 YJ total, the availability of solar power is 3.8 YJ per year.

Nuclear power

Main articles: Nuclear energy policy, Nuclear power by country

Worldwide, there are currently 435 operational nuclear power plants, with a further 30 under construction. Among the nations not currently using nuclear power, Iran, North Korea, Australia, Turkey, Indonesia, Vietnam, Egypt, Israel and Poland are building them, or are proposing to do so.
After stagnating in the West towards the end of the 20th century, Finland and the United States have ordered new nuclear plants. Various others are considering doing so, while some are planning to phase out nuclear power altogether.

Renewable energy

Main articles: Renewable energy

In 2004, renewable energy supplied around 7% of the world's energy consumption.^[9] The renewables sector has been growing significantly since the last years of the 20th century, and in 2005 the total new investment was estimated to have been 38 billion US dollars. Germany and China lead with investments of about 7 billion US dollars each, followed by the United States, Spain, Japan, and India. This resulted in an additional 35 GW of capacity during the year.²

Hydropower

Worldwide hydroelectricity consumption reached 816 GW in 2005, consisting of 750 GW of large plants, and 66 GW of small hydro installations. Large hydro capacity totaling 10.9 GW was added by China, Brazil and India during the year, but there was a much faster growth (8%) in small hydro, with 5 GW added, mostly in China where some 58% of the world's small hydro plants are now located.
In the western world although Canada is the largest producer of hydroelectricity in the world, the construction of large hydro plants has stagnated due to environmental concerns.^[10]

Biomass and biofuels

Until the end of the nineteenth century biomass was the predominant fuel, today it has only a small share of the overall energy supply. Electricity produced from biomass sources was estimated at 44 GW for 2005. Biomass electricity generation increased by over 100% in Germany, Hungary, the Netherlands, Poland and Spain. A further 220 GW was used for heating (in 2004), bringing the total energy consumed from biomass to around 264 GW. The use of biomass fires for cooking is excluded.²
World production of bioethanol increased by 8% in 2005 to reach 3.3 billion litres (0.872 billion US gallons), with most of the increase in the United States, bringing it level to the levels of consumption in Brazil.² Biodiesel increased by 85% to 3.9 billion litres (1.03 billion US gallons), making it the fastest growing renewable energy source in 2005. Over 50% is produced in Germany.²

Wind power

According to the Global Wind Energy Council, the installed capacity of wind power increased by 25.6% in from the end of 2005 to end of 2006 to total 74 GW with over half the increase in the United States, Germany, India and Spain.^[11] Doubling of capacity took about three and half years. The total installed capacity is approximately three times that of the actual average power produced as the nominal capacity represents peak output; actual capacity is generally from 25-40% of the nominal capacity.

Solar power

Solar energy used during 2005 was approximately 93.4 GW, however the available resources are 3.8 YJ/yr (120,000 TW). Only a small fraction of available resources are sufficient to entirely replace fossil fuels and nuclear power as an energy source, however it is likely that at least biodiesel will always be used in certain types of transport. Petroleum is expected to run out in 35 yrs, coal in 200 yrs. In practice neither will actually run out, as reliance diminishes.^[12][13]
In 2005 grid-connected photovoltaic electricity was the fastest growing renewable energy after biodiesel. During the year consumption increased by 55% on 2004 to bring the installed capacity to 3.1 GW. Over half of the increase was in Germany, now the world's largest consumer of photovoltaic electricity (followed by Japan). It was estimated that there was a further 2.3 GW of off-grid electricity produced, bringing the total to 5.4 GW.² Advances in technology and economies of scale along with demand for solutions to global warming have led photovoltaics to become the most likely candidate to replace nuclear and fossil fuels.^[14]
Portugal has opened the world's most powerful photovolaic solar power plant. The 11 megawatt solar power plant, comprising 52,000 photovoltaic modules is based in southern Portugal which is one of the sunniest places in Europe. It produces sufficient energy to power 8000 homes (see Renewable energy in Portugal).^[15]
The consumption of solar hot water and solar space heating was estimated at 88 GWt (gigawatts of thermal power) in 2004. The heating of water for unglazed swimming pools is excluded.²

Geothermal

Geothermal energy is used commercially in over 70 countries.^[16] By the end of 2005 worldwide use for electricity had reached 9.3 GW, with an additional 28 GW used directly for heating.² If heat recovered by ground source heat pumps is included, the non-electric use of geothermal energy is estimated at more than 100 GW.¹⁶

By country

Energy consumption broadly tracks with gross national product, although there is a significant difference between the consumption levels of the United States with 11.4 kW per person and Japan and Germany with 6 kW per person. Canada has the highest energy consumption per person, whereas the lowest energy consumption takes place in developing and under-developed economies. In developing countries such as India the per person energy use is closer to 0.5 kW.
The most significant growth of energy consumption is currently taking place in China, which has been growing at 5.5% per year over the last 25 years. Its population of 1.3 billion people is currently consuming energy at a rate of 2 kW per person.
One metric of efficiency is ''energy intensity''. This is a measure of the amount of energy it takes a country to produce a dollar of gross domestic product. Japan and the UK are among the most efficient in the world, while developing countries lack the resources to buy energy.

By sector

Industrial users (agriculture, mining, manufacturing, and construction) consume about 37% of the total 15 TW. Personal and commercial transportation consumes 20%; residential heating, lighting, and appliances use 11%; and commercial uses (lighting, heating and cooling of commercial buildings, and provision of water and sewer services) amount to 5% of the total.
^[17]
The other 27% of the world's energy is lost in energy transmission and generation. In 2005, global electricity consumption equaled 2 TW. The energy used to generate 2 TW of electricity is approximately 5 TW, as the efficiency of a typical existing power plant is around 38%.^[18] The new generation of gas-fired plants reaches a substantially higher efficiency of 55%. Coal is the most popular fuel for the world's electricity plants.^[19]

Resources

Fossil fuel

Despite several voices predicting the imminent decline of oil, the mainstream view is that there are still significant reserves of all traditional fossil fuels. Remaining reserves of conventional fossil fuels are estimated as: USGS World Energy Assessment Team

' Fuel '	'Energy reserves in ZJ'
Coal	290
Oil	18.4
Gas	15.7

Significant uncertainty exists for these numbers. The estimation of the remaining fossil fuels on the planet depends on a detailed understanding of the Earth crust. This understanding is still less than perfect. While modern drilling technology makes it possible to drill wells in up to 3 km of water to verify the exact composition of the geology, one half of the ocean is deeper than 3 km, leaving about a third of the planet beyond the reach of detailed analysis.

Coal

Coal is especially abundant and by itself could sustain the current energy consumption of the entire planet for 60 years. This was the fuel that launched the industrial revolution and has continued to grow in use; China, which already has many of the worlds most polluted cities,^[20] was in 2007 building about two coal fired power plants every week.^[21][22] Coal is the fastest growing fossil fuel and its large reserves would make it a popular candidate to meet the energy demand of the global community, short of concerns of global warming. With the Fischer-Tropsch process it is possible to make liquid fuels such as diesel and jet fuel from coal.

Oil

It is estimated that there may be 57 ZJ of oil reserves on Earth (although estimates vary from low of 8 ZJ, consisting of currently proven and recoverable reserves, to a maximum of 110 ZJ) consisting of available, but not necessarily recoverable reserves, and including optimistic estimates for unconventional sources such as tar sands and oil shale. Current oil consumption is at the rate of 0.18 ZJ per year.
There is growing consensus that peak oil production may be reached in the near future, resulting in severe oil price increases. A 2005 French Economics, Industry and Finance Ministry report suggested a worst case scenario that could occur as early as 2013.^[23] There are also theories that peak of the global oil production may occur in as little as 2-3 years. Some of them present the view that it has already taken place in 2005.

Sustainability

There is a broad consensus among scientists that we are not close to running out of fossil fuels.^[24] Despite this abundance, political considerations over the security of supplies, environmental concerns related to global warming and sustainability might move the world's energy consumption away from fossil fuels.
A government led move away from fossil fuels would most likely create economic pressure through carbon emissions trading and green taxation. Some countries are taking action as a result of the Kyoto Protocol, and further steps in this direction are proposed. For example, the European Commission has proposed that the energy policy of the European Union should set a binding target of increasing the level of renewable energy in the EU's overall mix from less than 7% today to 20% by 2020.^[25]

Nuclear power

Nuclear fission

The International Atomic Energy Agency estimates the remaining uranium resources to be equal to 2500 ZJ.^[26] This assumes the use of Breeder reactors which are able to create more fissile material than they consume. IPCC estimated uranium deposits for once-through fuel cycles reactors to be only 17 ZJ but then they go on to say that exploration for uranium is still at its infancy.^[27]
Resources and technology do not constrain the capacity of nuclear power to contribute to meeting the energy demand. However, political and environmental concerns about nuclear safety and radioactive waste started to limit the growth of this energy supply at the end of last century, particularly due to a number of nuclear accidents. Concerns about nuclear proliferation mean that the development of nuclear power by countries such as Iran is being actively discouraged by the international community.

Nuclear fusion

Fusion power is what powers our sun. It generates large quantities of heat by fusing the nuclei of hydrogen isotopes. The heat can theoretically be harnessed to generate electricity. The temperatures and pressures needed to sustain fusion make it a very difficult process to control and doing so is an unsolved technical challenge. The tantalizing potential of fusion is its theoretical ability to supply vast quantities of energy, with relatively little pollution.^[28] Both the United States and the European Union are supporting a moderate level of fusion-based research, along with other countries.

Renewable resources

Solar energy

Renewable energy sources are even larger than the traditional fossil fuels and in theory can easily supply the world's energy needs. 89 PW of solar power fall on the planet's surface. While it is not plausible to capture all, or even most, of this energy, capturing less than 0.02% would be enough to meet the current energy needs. Barriers to further solar generation include the high price of silicon used to make solar cells, reliance on weather patterns to generate electricity, a lack of space for solar cells in areas of high demand such as cities and they don't produce electricity during the night. The latter is a particular problem in the high northern and southern lattitude countries as energy demand is highest during the winter while availability of solar energy is lowest.

Wind power

The available wind energy estimates range from 300 TW to 370 TW. Using the lower estimate, just 5% of the available wind energy would supply the current worldwide energy needs. Most of this wind energy is available over the open ocean. The oceans cover 71% of the planet and wind tends to blow stronger over open water because there are fewer obstructions.

Wave and tidal power

At the end of 2005, 0.3 GW of electricity was produced by tidal power. Thanks to the gravitational pull of the moon (68%) and the sun (32%) there is 3 TW of tidal energy available of which approximately 1 percent is practical to exploit. The best site for capturing tidal energy is the much studied Bay of Fundy on the eastern border of the US and Canada. North America's only tidal power station is a 20 MW demonstration unit at the mouth of the Annapolis river in Nova Scotia.^[29]
Waves are derived from wind and wind is derived from solar energy, at each conversion there is approximately two orders drop in available energy. The energy in waves that wash against our shores add up to 3 TW.^[30]

Geothermal

Estimates of exploitable worldwide geothermal energy resources vary considerably. According to a 1999 study, it was thought that this might amount to between 65 and 138 GW of electrical generation capacity 'using enhanced technology'.^[31]
A 2006 report by MIT that took into account the use of Enhanced Geothermal Systems (EGS) concluded that it would be affordable to generate 100 GWe (gigawatts of electricity) or more by 2050, just in the United States, for a maximum investment of 1 billion US dollars in research and development over 15 years.¹⁶
The MIT report calculated the world's total EGS resources to be over 13 YJ, of which over 200 ZJ would be extractable, with the potential to increase this to over 2 YJ with technology improvements - sufficient to provide all the world's energy needs for several millennia.¹⁶

Alternative energy paths

Whether a significant investment in renewable energy and alternative energy is wise is currently the subject of much discussion. The debate rages between two very entrenched views. The renewable energy camp believes that the risk of global warming and the dependence on sources, such as those in the Middle East, justify a move away from fossil fuels. The other side of the debate believes, equally sincerely, that a government led switch to renewable energy will force economic dislocation, stifle and reverse economic growth and deny the developing world a path to prosperity.
Japan and Germany have started to make some investments in solar energy. They are now the largest consumers of photovoltaic cells in the world despite their unfavorable geographic locations. Denmark and Germany have installed 3 GW and 17 GW of wind power respectively. In 2005, wind generated 18.5% of all the electricity in Denmark.^[32]
Brazil invests in ethanol production from sugar cane which is now a significant part of the transportation fuel in that country.
Starting in 1965, France made large investments in nuclear power and to this date three quarters of its electricity comes from nuclear reactors.^[33] Switzerland is planning to cut its energy consumption by more than half to become a 2000 Watt society by 2050 and the United Kingdom is working towards a zero energy building standard for all new housing by 2016. In 2005, the Swedish government announced the oil phase-out in Sweden with the intention to become the first country to break its dependence on fossil fuel by 2020.
In the twenty first century, some of these different energy paths might become more mainstream and start replacing the ubiquitous fossil fuels.
It should be noted that between 1950 and 1984, as the Green Revolution transformed agriculture around the globe, world grain production increased by 250%. The energy for the Green Revolution was provided by fossil fuels in the form of fertilizers (natural gas), pesticides (oil), and hydrocarbon fueled irrigation.^[34] The peaking of world hydrocarbon production (Peak oil) may test Malthus critics.^[35]

See also

★

★ Carbon emissions by country

★ Electricity consumption by country

★ Earth's energy budget

★ Electricity generation

★ Energy development

★ Energy use in the United States

★ Energy use and conservation in the United Kingdom

★ Oil phase-out in Sweden

★ Kardashev scale

Footnotes

1. BP Statistical review of world energy June 2006
2. Renewables, Global Status Report 2006
3. Historical Statistics of Japan
4. Smil, p. 204

★ Tester, et al, p. 303

★ OPEC 2005 Annual Statistical Bulletin
5. Data to produce this graphic was taken from a NASA publication.
6. Smil, p. ?
7. Yergin, p. 792
8. Yergin, p. ?
9. Photovoltaics
10. Environmental Impacts of Renewable Energy Technologies (adapted from material in the UCS book Cool Energy: Renewable Solutions to Environmental Problems, by Michael Brower (MIT Press, 1992), 220 pp)
11. Global wind energy markets
12. Oil, the Dwindling Treasure
13. World Energy Reserves
14. Why PV is important.
15. Portugal starts huge solar plant
16. The Future of Geothermal Energy
17.
International Energy Outlook 2007
18. Energy efficiency measures and technological improvements. Article by group of ten leading electricity companies
19. Coal Facts 2006 Edition
20. The Middle Landfill
21. China building more power plants
22. COAL: Scrubbing its future
23. 'Peak oil' enters mainstream debate Adam Porter
24. Smil, p. ?
25. Communication from the Commission to the European Parliament and the Council: Renewable Energy Roadmap: Renewable Energies in the 21st century; building a sustainable future - COM(2006) 848
26. Global Uranium Resources to Meet Projected Demand: Latest Edition of "Red Book" Predicts Consistent Supply Up to 2025
27. IPCC Special Report on Emissions Scenarios Nakicenovic, Nebojsa et al.
28. Fusian Energy: Safety European Fusion Development Agreement (EFDA). 2006. Retrieved on 2007-04-03
29. Tester, et al, pp. 592, 593, 596
30. Tester, et al, p. 593
31.
All About Geothermal energy
32. Danish Annual Energy Statistics
33. Smil, p. ?
34. Eating Fossil Fuels | EnergyBulletin.net
35. Peak Oil: the threat to our food security

References

★ Smil, Vaclav. (2003) ''Energy at the crossroads'' MIT Press. ISBN 0-262-19492-9

★ Tester, Jefferson W. ''et al''. (2005) ''Sustainable Energy: Choosing Among Options.'' The MIT Press. ISBN 0-262-20153-4

★ Yergin, Daniel (1993). ''The Prize''. Simon & Schuster: New York. ISBN 0-671-79932-0

External links

★ World Energy Outlook

★ Official Energy Statistics from the US government

★ Annual Energy Review 2005, DOE/EIA-0384(2006), by the U.S. Department of Energy's Energy Information Administration (PDF)

★ United States Geological Survey

★ TrendLines' current Peak Oil Depletion Scenarios Graph A monthly compilation update of 16 recognized estimates of URR, Peak Year & Peak Rate

★ RECaBS REcalculator Interactive Renewable Energy Calculator for estimating costs and benefits of renewable energy for electricity production compared to traditional energy sources