In order to directly compare world energy resources and consumption of energy, this article uses SI units and prefixes and measures energy rate (or power) in watts (W) and amounts of energy in joules (J). In Physics, power (symbol P) is the rate at which work is performed or energy is transmitted or the amount of energy required or expended for The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity One watt is one joule per second.
In 2005, total worldwide energy consumption was 500 EJ (= 5 x 1020 J) with 86. exa- (symbol E) is a prefix in the SI system of units denoting 1018 or 1 000 000 000 000 000 000 5% derived from the combustion of fossil fuels, although there is at least 10% uncertainty in that figure. Fossil fuels or mineral fuels are fossil source Fuels that is Hydrocarbons found within the top layer of the Earth’s crust.  This is equivalent to 15 TW (= 1. 5 x 1013 W) of power. 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 quality.
Most of the world energy resources are from the sun's rays hitting earth - some of that energy has been preserved as fossil energy, some is directly or indirectly usable e. g. via wind, hydro or wave power. The term solar constant is the amount of incoming solar electromagnetic radiation per unit area, measured on the outer surface of Earth's atmosphere, in a plane perpendicular to the rays. The solar constant includes all types of solar radiation, not just the visible light. It is measured by satellite to be roughly 1366 watts per square meter, though it fluctuates by about 6. 9% during a year - from 1412 W/m2 in early January to 1321 W/m2 in early July, due to the earth's varying distance from the sun, and by a few parts per thousand from day to day. For the whole Earth, with a cross section of 127,400,000 km², the power is 1.740×1017 W, plus or minus 3. This page lists examples of the power in Watts produced by various different sources of energy The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. 5%.
The estimates of remaining worldwide energy resources vary, with the remaining fossil fuels totaling an estimated 0. 4 YJ (1 YJ = 1024J) and the available nuclear fuel such as uranium exceeding 2. Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the 5 YJ. Fossil fuels range from 0. 6-3 YJ if estimates of reserves of methane clathrates are accurate and become technically extractable. Methane clathrate, also called methane hydrate or methane ice, is a solid form of water that contains a large amount of Methane within its Crystal 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. "Available energy" redirects here For the meaning of the term in particle collisions see Available energy (particle collision. 8 YJ/yr, dwarfing all non-renewable resources.
Since the advent of the industrial revolution, the worldwide energy consumption has been growing steadily. The Industrial Revolution was a period in the late 18th and early 19th centuries when major changes in agriculture manufacturing and transportation had a profound effect on the In 1890 the consumption of fossil fuels roughly equaled the amount of biomass fuel burned by households and industry. Year 1890 ( MDCCCXC) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common Biomass refers to living and recently dead Biological material that can be used as fuel or for industrial production In 1900, global energy consumption equaled 0. Year 1900 ( MCM) was an exceptional Common year starting on Monday (link will display the full calendar of the Gregorian calendar 7 TW (0. 7×1012 watts). This list compares various sizes of positive Numbers including counts of things Dimensionless quantity and probabilities. 
The twentieth century saw a rapid twentyfold increase in the use of fossil fuels. Fossil fuels or mineral fuels are fossil source Fuels that is Hydrocarbons found within the top layer of the Earth’s crust. Between 1980 and 2004, the worldwide annual growth rate was 2%. Year 1980 ( MCMLXXX) was a Leap year starting on Tuesday (link displays the 1980 Gregorian calendar) "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again "  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. The United States Energy Information Administration (EIA created by Congress in 1977, is the independent statistical agency within the U teras- (symbol T) is a prefix in the SI system of units denoting 1012, or 1000000000000 (1 trillion exa- (symbol E) is a prefix in the SI system of units denoting 1018 or 1 000 000 000 000 000 000 6||180|
Coal fueled the industrial revolution in the 18th and 19th century. With the advent of the automobile, airplanes and the spreading use of electricity, oil became the dominant fuel during the twentieth century. Petroleum ( L petroleum, from Greek πετρέλαιον, lit 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.  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, which is one of the dirtiest sources of energy, has become the fastest growing fossil fuel. . Photovoltaics, however, is rapidly becoming available to replace fossil fuels as the dominant energy source. Photovoltaics ( PV) is the field of technology and research related to the application of Solar cells for Energy by converting Sunlight directly  Note the earlier comparison of availability: The total resources of all fossil fuels amount to about 0. 4 YJ total, while the availability of solar energy is 3. Solar energy is the Light and radiant heat from the Sun that powers Earth 's Climate and Weather and sustains Life 8 YJ per year.
In 2005 nuclear energy accounted 6. See also Nuclear power Nuclear energy policy is a national and international Policy concerning some or all aspects of Nuclear energy, such as Nuclear power is a method for generating energy by harnessing the radioactivity of atoms 3% of world's total primary energy supply.  The nuclear power production in 2006 accounted 2,658 TWh, which was 16% of world's total electricity production.  In November 2007, there were 439 operational nuclear reactors worldwide, with total capacity of 372,002 MWe. This article is a subarticle of Nuclear power. A nuclear reactor is a device in which Nuclear chain reactions are initiated controlled A further 33 reactors were under construction, 94 reactors were planned and 222 reactors were proposed.  Among the nations not currently using nuclear power, 25 countries are building them, or are proposing to do so. Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions  A few nations have announced plans to phase out nuclear power altogether, but to date only Italy has done so (though Italy continues to import electricity from nations with active nuclear power plants). Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest  In addition, while Austria, the Philippines and North Korea have built nuclear power stations, these nations abandoned them before they could be fueled and operated. Austria (Österreich ( officially the Republic of Austria (Republik Österreich The Philippines ( Filipino: Pilipinas, officially known as the Republic of the Philippines (fil ''Republika ng Pilipinas'' RP North Korea is the commonly used short form name for the Democratic People's Republic of Korea (or DPRK) a State located in East Asia,
In 2004, renewable energy supplied around 7% of the world's energy consumption. Renewable energy is Energy generated from Natural resources mdashsuch as Sunlight, Wind, Rain, tides and geothermal  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. The twentieth century of the Common Era began on Germany and China lead with investments of about 7 billion US dollars each, followed by the United States, Spain, Japan, and India. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National The United States of America —commonly referred to as the Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. For a topic outline on this subject see List of basic Japan topics. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country This resulted in an additional 35 GW of capacity during the year. The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. 
Worldwide hydroelectricity consumption reached 816 GW in 2005, consisting of 750 GW of large plants, and 66 GW of small hydro installations. Hydropower, hydraulic power or water power is power that is derived from the Force or Energy of moving water which may Hydroelectricity is electricity generated by Hydropower, ie the production of power through use of the gravitational force of falling water Small hydro is the development of Hydroelectric power on a scale serving a small community or industrial plant 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. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country 
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. The term Western world, the West or the Occident ( Latin: occidens -sunset -west as distinct from the Orient) can have multiple meanings Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page  The trend in both Canada and the United States has been to micro hydro because it has negligible environmental impacts and opens up many more locations for power generation. Micro Hydro is a term used for Hydroelectric power installations that typically produce up to 100 kW of power In British Columbia alone the estimates are that micro hydro will be able to more than double electricity production in the province.
Until the end of the nineteenth century biomass was the predominant fuel, today it has only a small share of the overall energy supply. Biomass refers to living and recently dead Biological material that can be used as fuel or for industrial production Electricity produced from biomass sources was estimated at 44 GW for 2005. Biomass refers to living and recently dead Biological material that can be used as fuel or for industrial production Biomass electricity generation increased by over 100% in Germany, Hungary, the Netherlands, Poland and Spain. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Hungary (Magyarország 'mɔɟɔrorsaːg) officially in English the Republic of Hungary ( Magyar Köztársaság, literally Magyar (Hungarian Republic The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands Poland (Polska officially the Republic of Poland Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. 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. 
World production of bioethanol increased by 8% in 2005 to reach 33 billion litres (8. Ethanol fuel is Ethanol (ethyl alcohol the same type of Alcohol found in Alcoholic beverages. The litre or liter (see spelling differences) is a unit of Volume. 72 billion US gallons), with most of the increase in the United States, bringing it level to the levels of consumption in Brazil. A gallon is a measure of Volume. It is in current use in the United States and still has limited use in many other English-speaking countries The United States of America —commonly referred to as the |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld  Biodiesel increased by 85% to 3. Biodiesel refers to a non-petroleum-based Diesel fuel consisting of short chain Alkyl ( Methyl or ethyl) Esters made by 9 billion litres (1. 03 billion US gallons), making it the fastest growing renewable energy source in 2005. Over 50% is produced in Germany. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. 
According to the Global Wind Energy Council, the installed capacity of wind power increased by 27% from the end of 2006 to the end of 2007 to total 94. Wind Power is the conversion of wind energy into a useful form such as electricity using Wind turbines At the end of 2007 worldwide capacity of wind-powered generators was The Global Wind Energy Council (GWEC was established in 2005 to provide a credible and representative forum for the entire wind energy sector at an international level Wind Power is the conversion of wind energy into a useful form such as electricity using Wind turbines At the end of 2007 worldwide capacity of wind-powered generators was 1 GW, with over half the increase in the United States, Spain and China. Wind power in the United States is a growing industry In 2007 the United States was the fastest growing wind power market in the world for the third year in a row See also Renewable energy in Spain Spain is one of the three world’s largest users of Wind power with an installed capacity At the end of 2007 wind power in China accounted for less than one per cent of electricity production in the country with an installed capacity of just over 6 gigawatts (GW  Doubling of capacity took about three 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. Wind Power is the conversion of wind energy into a useful form such as electricity using Wind turbines At the end of 2007 worldwide capacity of wind-powered generators was 
The available solar energy resources are 3. Solar energy is the Light and radiant heat from the Sun that powers Earth 's Climate and Weather and sustains Life 8 YJ/yr (120,000 TW). TERA is a shielded Twisted pair connector for use with Category 7 twisted-pair data cables developed by The Siemon Company and standardized in 2003 by Less than 0. 02% of available resources are sufficient to entirely replace fossil fuels and nuclear power as an energy source. Assuming that our current rate of usage remains constant, we will run out of conventional oil in 35 years, coal in 200 yrs. In practice neither will actually run out, as natural constraints will force production to decline as the remaining reserves dwindle. 
In 2007 grid-connected photovoltaic electricity was the fastest growing energy source, with installations of all photovoltaics increasing by 83% in 2007 to bring the total installed capacity to 8. Electric power transmission, a process in the delivery of Electricity to consumers is the bulk transfer of electrical power Photovoltaics ( PV) is the field of technology and research related to the application of Solar cells for Energy by converting Sunlight directly 7 GW. Nearly half of the increase was in Germany, now the world's largest consumer of photovoltaic electricity (followed by Japan). Strong demand for solar cells from German farmers and homeowners resulted in another record year for the installation of solar Photovoltaic (PV systems in the country according to data Solar cell production increased by 50% in 2007, to 3,800 megawatts, and has been doubling every two years. 
The world's most powerful photovoltaic solar power plant is the 20 megawatt Beneixama photovoltaic power plant in Spain, although a 116 megawatt plant is under construction in southern Portugal, one of the sunniest places in Europe. Beneixama photovoltaic power plant is a 20 MW Photovoltaic Power plant located in Beneixama, Spain. A large Photovoltaic power project the Serpa solar power plant, has been completed in Portugal, in one of the Europe's sunniest areas  The largest photovoltaic installation in North America is the 18 megawatt Nellis Solar Power Plant. The Nellis Solar Power Plant is the largest solar Photovoltaic system in North America, and is located within Nellis Air Force Base in Clark County
Since 1991 the largest solar power plant has been the 354 megawatt Solar Energy Generating Systems, in California, using parabolic trough collectors. Solar Energy Generating Systems (SEGS is the largest Solar energy generating facility in the world A parabolic trough is a type of Solar thermal energy collector
The consumption of solar hot water and solar space heating was estimated at 88 GWt (gigawatts of thermal power) in 2004. Solar hot water is water heated by the use of Solar energy. Solar heating systems are generally composed of solar Thermal collectors a Fluid Central solar heating is the provision of Central heating and hot water from Solar energy by a system in which the water is heated centrally by arrays of The heating of water for unglazed swimming pools is excluded. 
Geothermal energy is used commercially in over 7 countries. Geothermal power (from the Greek roots geo, meaning earth and therme, meaning heat is energy generated by heat stored in the earth or the collection Geothermal power (from the Greek roots geo, meaning earth and therme, meaning heat is energy generated by heat stored in the earth or the collection  By the end of 2005 worldwide use for electricity had reached 9. Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. 3 GW, with an additional 28 GW used directly for heating.  If heat recovered by ground source heat pumps is included, the non-electric use of geothermal energy is estimated at more than 100 GW. A geothermal heat pump system is a heating and/or an Air conditioning system that uses the Earth's ability to store heat in the ground and water Thermal 
Energy consumption broadly tracks with gross national product, although there is a significant difference between the consumption levels of the United States with 11. This is a list of countries by total Energy consumption per capita as published by the World Resources Institute for the year 2003 4 kW per person and Japan and Germany with 6 kW per person. For a topic outline on this subject see List of basic Japan topics. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. In developing countries such as India the per person energy use is closer to 0. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country 7 kW. Bangladesh has the lowest consumption with 0. 2 kW per person.
The US consumes 25% of the world's energy (with a share of global productivity at 22% and a share of the world population at 5%). The most significant growth of energy consumption is currently taking place in China, which has been growing at 5. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National 5% per year over the last 25 years. Its population of 1. 3 billion people is currently consuming energy at a rate of 1. 6 kW per person.
Over the past four years, electricity consumption per capita in the U. S. has decreased about 1% per year between 2004 and 2008. Power consumption is projected to hit 4,333,631 million kilowatt hours by 2013, a growth of 1. 93% over the next five years. Consumption increased from 3,715,949 in 2004 to an expected 3,937,879 million kilowatt hours per year in 2008, an increase of about 0. 36% per year. U. S. population has been increasing about 1. 3% per year, a total increase of about 6. 7% over five years.  The decrease has been mostly due to efficiency increases. Compact fluorescent bulbs, for example use about one third as much electricity as incandescents. LED bulbs, however, use about one tenth as much, and over their 50,000 to 100,000 hour lifetime are cheaper than compact fluorescents.
One metric of efficiency is energy intensity. Energy intensity is a measure of the energy efficiency of a nation's economy. This is a measure of the amount of energy it takes a country to produce a dollar of gross domestic product.
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. 
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%.  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. 
Remaining reserves of conventional fossil fuels are estimated as:
|Fuel||Energy reserves in ZJ|
|Coal||290. Fossil fuels or mineral fuels are fossil source Fuels that is Hydrocarbons found within the top layer of the Earth’s crust. 0|
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. An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere. At the same time, long before fossil fuels run out, the effect of continuing to use them at current rates would cause havoc to the climate through global warming.  These figures may be too optimistic. Energy Watch Group reports show that we already cannot supply the demand for oil and that uranium resources will be exhausted within 70 years. 
Coal is the most abundant fossil fuel. According to the International Energy Agency the proven reserves of coal are around 909 billion tonnes, which could sustain at the current production rate for 155 years. The International Energy Agency ( IEA, or AIE in Romance languages) is a Paris -based intergovernmental organization founded by the Organisation  This was the fuel that launched the industrial revolution and has continued to grow in use; China, which already has many of the world's most polluted cities, was in 2007 building about two coal fired power plants every week. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century.  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 global warming concerns and other pollutants.  With the Fischer-Tropsch process it is possible to make liquid fuels such as diesel and jet fuel from coal. The Fischer-Tropsch process (or Fischer-Tropsch Synthesis is a catalyzed chemical reaction in which synthesis gas ( Syngas) a mixture of Carbon monoxide The Stop Coal campaign calls for a moratorium on the construction of any new coal plants and on the phase out of all existing plants, citing concern for global warming.  In the United States, 49% of electricity generation comes from burning coal. 
It is estimated that there may be 57 ZJ of oil reserves on Earth (although estimates vary from a 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. Oil reserves are the estimated quantities of Crude oil that are claimed to be recoverable under existing Economic and operating conditions Current consensus among the 18 recognized estimates of supply profiles is that the peak of extraction will occur in 2020 at the rate of 93-million barrels per day (mbd). Current oil consumption is at the rate of 0. 18 ZJ per year (31. 1 billion barrels) or 85-mbd.
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. The Minister for the Economy Industry and Employment ( ministre de l'Économie de l'Industrie et de l'Emploi) or Minister of Finance for short is one of the  There are also theories that peak of the global oil production may occur in as little as 2-3 years. The ASPO predicts peak year to be in 2010. Some other theories present the view that it has already taken place in 2005. World oil production decreased from 84. 63 mbd in 2005 to 84. 60 mbd in 2006 but increased in 2007 to 84. 66 mbd, and is projected to increase to 87. 70 mbd in 2009.
Political considerations over the security of supplies, environmental concerns related to global warming and sustainability will move the world's energy consumption away from fossil fuels. Global warming is the increase in the average measured temperature of the Sustainability, in a general sense is the capacity to maintain a certain process or state indefinitely The concept of peak oil shows that we have used about half of the available petroleum resources, and predicts a decrease of production.
A government led move away from fossil fuels would most likely create economic pressure through carbon emissions trading and green taxation. Emissions trading (or emission trading) is an administrative approach used to control Pollution by providing economic Incentives for Ecotax, short for Ecological taxation, can refer to A policy that introduces taxes intended to promote ecologically sustainable activities via economic incentives Some countries are taking action as a result of the Kyoto Protocol, and further steps in this direction are proposed. The Kyoto Protocol is a protocol to the international Framework Convention on Climate Change with the objective of reducing Greenhouse gases in an effort 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. The European Commission (formally the Commission of the European Communities) is the executive branch of the European Union. Although the European Union has legislated in the area of energy policy for many years and evolved out of the European Coal and Steel Community, the concept of introducing a 
The Easter Island Effect is cited as an example of a culture that was unable to develop sustainability and depleted nearly 100% of its natural resources. 
The International Atomic Energy Agency estimates the remaining uranium resources to be equal to 2500 ZJ. Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions See also Nuclear power Nuclear energy policy is a national and international Policy concerning some or all aspects of Nuclear energy, such as Nuclear fuel is any material that can be consumed to derive Nuclear energy, by analogy to chemical Fuel that is burned to derive energy The International Atomic Energy Agency ( IAEA) is an international organization that seeks to promote the peaceful use of nuclear energy and to inhibit its  This assumes the use of Breeder reactors which are able to create more fissile material than they consume. A breeder reactor is a Nuclear reactor that generates new Fissile or fissionable material at a greater rate than it consumes such material In Nuclear engineering, a fissile material is one that is capable of sustaining a Chain reaction of Nuclear fission. IPCC estimated currently proved economically recoverable uranium deposits for once-through fuel cycles reactors to be only 2 ZJ. The ultimately recoverable uranium is estimated to be 17 ZJ for once-through reactors and 1000 ZJ with reprocessing and fast breeder reactors. 
Resources and technology do not constrain the capacity of nuclear power to contribute to meeting the energy demand for the 21st century. 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. See also Nuclear debate Nuclear safety covers the actions taken to prevent Nuclear and radiation accidents or to limit their consequences Radioactive wastes are Waste types containing radioactive Chemical elements that do not have a practical purpose This article lists notable civilian accidents involving nuclear material Concerns about nuclear proliferation (especially with Plutonium produced by breeder reactors) mean that the development of nuclear power by countries such as Iran and Syria is being actively discouraged by the international community. Nuclear proliferation is a term now used to describe the spread of Nuclear weapons, fissile material and weapons-applicable nuclear technology and information to nations The nuclear program of Iran was launched in the 1950s with the help of the United States as part of the Atoms for Peace program Syria ( سوريّة or) officially the Syrian Arab Republic (Arabic ar الجمهورية العربية السورية 
Fusion power is the process driving our sun and other stars. Fusion power is power generated by Nuclear fusion reactions In this kind of reaction two light atomic nuclei fuse 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.  Both the United States and the European Union are supporting a moderate level of research (such as investing in the ITER facility), along with other countries. ITER is an international Tokamak ( Magnetic confinement fusion) research/engineering proposal for an experimental project that will help to make the transition from Fusion has remained 50 years away for the last 60 years, and is now seen as being 50 to 250 years away from commercial availability. 
Renewable resources are available each year, unlike non-renewable resources which are eventually depleted. A natural resource qualifies as a renewable resource if it is replenished by natural processes at a rate comparable or faster than its rate of consumption by humans or other users A simple comparison is a coal mine and a forest. While the forest could be depleted, if it is managed properly it represents a continuous supply of energy, vs the coal mine which once it has been exhausted is gone. Most of earth's available energy resources are renewable resources. Renewable resources account for more than 93 percent of total U. S. energy reserves. Annual renewable resources were multiplied times thirty years for comparison with non-renewable resources. In other words, if all non-renewable resources were uniformly exhausted in 30 years, they would only account for 7 percent of available resources each year, if all available renewable resources were developed. 
Renewable energy sources are even larger than the traditional fossil fuels and in theory can easily supply the world's energy needs. Solar energy is the Light and radiant heat from the Sun that powers Earth 's Climate and Weather and sustains Life 89 PW of solar power fall on the planet's surface. While it is not possible 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 and a lack of space for solar cells in areas of high demand, such as cities. Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 A solar cell or photovoltaic cell is a device that converts Solar energy into Electricity by the photovoltaic effect. Also, solar generation does not produce electricity at night, which is a particular problem in high northern and southern latitude countries; energy demand is highest in winter, while availability of solar energy is lowest. Globally, solar generation is the fastest growing source of energy, seeing an annual average growth of 35% over the past few years. Japan, Europe, China, U.S. and India are the major growing investors in solar energy. For a topic outline on this subject see List of basic Japan topics. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National The United States of America —commonly referred to as the India is both densely populated and has high solar insolation providing an ideal combination for solar power in India. 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. Global warming is the increase in the average measured temperature of the Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions Fossil fuels or mineral fuels are fossil source Fuels that is Hydrocarbons found within the top layer of the Earth’s crust. 
The available wind energy estimates range from 300 TW to 870 TW. Wind Power is the conversion of wind energy into a useful form such as electricity using Wind turbines At the end of 2007 worldwide capacity of wind-powered generators was  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. An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere.
At the end of 2005, 0. Wave power refers to the Energy of Ocean surface waves and the capture of that energy to do useful work — including Electricity generation, Tidal power, sometimes called tidal energy, is a form of Hydropower that converts the energy of Tides into electricity or other useful forms of power 3 GW of electricity was produced by tidal power. Tidal power, sometimes called tidal energy, is a form of Hydropower that converts the energy of Tides into electricity or other useful forms of power  Due to the tidal forces created by the Moon (68%) and the Sun (32%), and the Earth's relative rotation with respect to Moon and Sun, there are fluctuating tides. The tidal force is a secondary effect of the Force of Gravity and is responsible for the Tides It arises because the gravitational acceleration experienced These tidal fluctuations result in dissipation at an average rate of about 3. In Physics, dissipation embodies the concept of a Dynamical system where important mechanical modes such as Waves or Oscillations lose Energy 7 TW.  As a result, the rotational speed of the Earth decreases, and the distance of the Moon to the Earth increases, on geological time scales. Rotational speed (sometimes called speed of revolution) indicates for example how fast a motor is running The geologic time scale is a chronologic schema (or idealized Model) relating Stratigraphy to time that is used by Geologists and other In several billion years, the Earth will rotate at the same speed as the Moon is revolving around it. So, several TW of tidal energy can be produced without having a significant effect on celestial mechanics. Celestial mechanics is the branch of Astrophysics that deals with the motions of Celestial objects The field applies principles of Physics, historically
Another physical limitation is the energy available in the tidal fluctuations of the oceans, which is about 0. 6 EJ (exajoule). exa- (symbol E) is a prefix in the SI system of units denoting 1018 or 1 000 000 000 000 000 000 The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity  Note this is only a tiny fraction of the total rotational energy of the Earth. The rotational energy or angular kinetic energy is the Kinetic energy due to the rotation of an object and is part of its total kinetic energy. Without forcing, this energy would be dissipated (at a dissipation rate of 3. 7 TW) in about four semi-diurnal tide periods. So, dissipation plays a significant role in the tidal dynamics of the oceans. Therefore, this limits the available tidal energy to around 0. 8 TW (20% of the dissipation rate) in order not to disturb the tidal dynamics too much.
Waves are derived from wind, which is in turn derived from solar energy, and at each conversion there is a drop of about two orders of magnitude in available energy. The energy fluxes of waves that wash against our shores add up to 3 TW. In the various subfields of Physics, there exist two common usages of the term flux, both with rigorous mathematical frameworks 
Estimates of exploitable worldwide geothermal energy resources vary considerably. Geothermal power (from the Greek roots geo, meaning earth and therme, meaning heat is energy generated by heat stored in the earth or the collection Geothermal power (from the Greek roots geo, meaning earth and therme, meaning heat is energy generated by heat stored in the earth or the collection 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'. Year 1999 ( MCMXCIX) was a Common year starting on Friday (link will display full 1999 Gregorian calendar) 
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. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Hot Dry Rock Geothermal Energy (HDR is a type of Geothermal power production that uses the very high temperatures (approx 200 Celsius that can be found in rocks 2050 ( MML) will be a Common year starting on Saturday of the Gregorian calendar. The United States of America —commonly referred to as the 
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. A millennium (pl millennia) is a period of Time equal to one thousand Years (from Latin la mille, thousand and la annum 
Production of biomass and biofuels are growing industries as interest in sustainable fuel sources is growing. Biomass refers to living and recently dead Biological material that can be used as fuel or for industrial production Utilizing waste products avoids a food vs fuel trade-off, and burning methane gas reduces greenhouse gas emissions, because even though it releases carbon dioxide, carbon dioxide is 23 times less of a greenhouse gas than is methane. Food vs fuel is the dilemma regarding the risk of diverting farmland or crops for Biofuels production in detriment of the Food Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. Biofuels represent a sustainable partial replacement for fossil fuels, but their net impact on greenhouse gas emissions depends on the agricultural practices used to grow the plants used as feedstock to create the fuels. Greenhouse gases are gaseous constituents of the atmosphere bothnatural and anthropogenic that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared While it is widely believed that biofuels can be carbon-neutral, there is evidence that biofuels produced by current farming methods are substantial net carbon emitters.  Geothermal and biomass are the only two renewable energy sources which require careful management to avoid local depletion. 
Hydroelectric power now supplies about 715,000 MWe or 19% of world electricity (16% in 2003). Hydropower, hydraulic power or water power is power that is derived from the Force or Energy of moving water which may The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. Large dams are still being designed. Nevertheless, hydroelectric power is probably not a major option for the future of energy production in the developed nations because most major sites within these nations are either already being exploited or are unavailable for other reasons, such as environmental considerations.
Denmark and Germany have started to make investments in solar energy, despite their unfavorable geographic locations. The Kingdom of Denmark ( ˈd̥ænmɑɡ̊ (archaic ˈd̥anmɑːɡ̊ commonly known as Denmark, is a country in the Scandinavian region of northern Europe Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Germany is now the largest consumer of photovoltaic cells in the world. A solar cell or photovoltaic cell is a device that converts Solar energy into Electricity by the photovoltaic effect. Denmark and Germany have installed 3 GW and 17 GW of wind power respectively. Wind Power is the conversion of wind energy into a useful form such as electricity using Wind turbines At the end of 2007 worldwide capacity of wind-powered generators was In 2005, wind generated 18. 5% of all the electricity in Denmark.  Brazil invests in ethanol production from sugar cane which is now a significant part of the transportation fuel in that country. |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld Ethanol fuel is Ethanol (ethyl alcohol the same type of Alcohol found in Alcoholic beverages. Starting in 1965, France made large investments in nuclear power and to this date three quarters of its electricity comes from nuclear reactors. This article is about the country For a topic outline on this subject see List of basic France topics.  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. Switzerland (English pronunciation; Schweiz Swiss German: Schwyz or Schwiiz Suisse Svizzera Svizra officially the Swiss Confederation The 2000-watt society (2000-Watt Society is a vision originated by the Swiss Federal Institute of Technology in Zürich at the end of 1998 in which each person in the The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located A zero energy building ( ZEB) or net zero energy building is a general term applied to a Building with a net energy consumption of zero over a typical year 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. "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. In 2005 the Government of Sweden announced their intention to make Sweden the first country to break its dependence on Petroleum, Natural gas Fossil fuels or mineral fuels are fossil source Fuels that is Hydrocarbons found within the top layer of the Earth’s crust.
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 Green Revolution refers to the transformation of Agriculture that began in 1945 at the request of the Mexican government to establish an agricultural research station to Agriculture refers to the production of goods through the growing of plants and fungi and the raising of domesticated Animals The study of agriculture The energy for the Green Revolution was provided by fossil fuels in the form of fertilizers (natural gas), pesticides (oil), and hydrocarbon fueled irrigation. Fossil fuels or mineral fuels are fossil source Fuels that is Hydrocarbons found within the top layer of the Earth’s crust. Fertilizers ( also spelt fertiliser are chemical compounds given to Plants to promote growth they are usually applied either through the soil for uptake by plant A pesticide is a substance or mixture of substances used to kill a pest. In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. Irrigation is an artificial application of water to the soil usually for assisting in growing crops  The peaking of world hydrocarbon production (Peak oil) may test Malthus critics. Thomas Robert Malthus FRS (13 February 1766 – 23 December 1834 was an English political economist and demographer who expressed views