Primary energy
The United States Energy Information Administration regularly publishes a report on world consumption for most types of primary energy resources.
| Fuel type | Average power in TW[12] | ||
| 1980 | 2004 | 2006 | |
| Oil | 4.38 | 5.58 | 5.74 |
| Gas | 1.80 | 3.45 | 3.61 |
| Coal | 2.34 | 3.87 | 4.27 |
| Hydroelectric | 0.599 | 0.933 | 0.995 |
| Nuclear power | 0.253 | 0.914 | 0.929 |
| Geothermal, wind, solar energy, wood | 0.016 | 0.133 | 0.158 |
| Total | 9.48 | 15.0 | 15.8 |
Fossil fuels
The twentieth century saw a rapid twentyfold increase in the use of fossil fuels. Between 1980 and 2006, the worldwide annual growth rate was 2%.[1] According to the US Energy Information Administration's 2006 estimate, the estimated 471.8 EJ total consumption in 2004 was divided as follows, with fossil fuels supplying 86% of the world's energy:
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. 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.[13] Coal, natural gas, and nuclear became the fuels of choice for electricity generation and conservation measures increased energy efficiency. In the U.S. the average car more than doubled the number of miles per gallon. Japan, which bore the brunt of the oil shocks, made spectacular improvements and now has the highest energy efficiency in the world.[5] From 1965 to 2008, the use of fossil fuels has continued to grow and their share of the energy supply has increased. From 2003 to 2008, coal, which is one of the dirtiest sources of energy,[14] was the fastest growing fossil fuel.[15].
Nuclear power
In 2005 nuclear power accounted for 6.3% of world's total primary energy supply.[16] The nuclear power production in 2006 accounted 2,658 TWh (23.3 EJ), which was 16% of world's total electricity production.[17][18] In November 2007, there were 439 operational nuclear reactors worldwide, with total capacity of 372,002 MWe. A further 33 reactors were under construction, 94 reactors were planned and 222 reactors were proposed.[17] The people in the US have been and are being led to believe that the development of nuclear power in the world essentially ended with Chernobyl[citation needed], but several CANDU reactors have been reactivated in Canada and two new ones put into service in China. One CANDU, at least, is being finished in Romania. Another CANDU is being refurbished in Canada. A new reactor is being built in France and another ordered. A new design one is being built in Finland, but is far behind schedule. Italy has formed a consortium with French companies to build new reactors in Italy. China has built other reactors and ordered two new ones from Russia. Japan has continued operating and building nuclear power plants, and both Canada and Australia are expanding their uranium mines and exports. After new elections, the German government is revising its intent to continue using nuclear power and has bought a lot of it from France. The US has enrichment facilities being planned as well as new nuclear reactors. A Canadian company has selected a site for a nuclear reactor to generate heat for bitumen extraction from tar sands. The US has an approved operational repository in a deep salt bed for nuclear radiative materials of all forms that has received materials of many kinds, but is only authortized for governmental military materials, but contains materials from reactor prototypes of commercial reactors. If coal, gas or oil electric generators are replaced by nuclear power plants, they must be considered CO2 negative when a pound of recycled military plutonium or uranium can replace 3,000,000 pounds of coal energy, and the fossil energy used in construction and fuel mining and preparation is replaced by CO2 free generation in a few months. The IAEA has news of all these reactors and more. Former anti nuclear activist, Gwyneth Cravens, revisited her anti nuclear thoughts in her book "Power to Save the World" in 2007 because of chance meeting with a nuclear scientist and subsequent discussions about energy and concerns of global warming and heath effects from using fossil fuels.
Renewable energy
In 2004, renewable energy supplied around 7% of the world's energy consumption.[19] 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.[3]
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.[3]
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.[20] 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. In British Columbia alone the estimates are that micro hydro will be able to more than double electricity production in the province.
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.[3]
World production of bioethanol increased by 8% in 2005 to reach 33 billion litres (8.72 billion US gallons), with most of the increase in the United States, bringing it level to the levels of consumption in Brazil.[3] 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.[3]
Wind power
According to the World Wind Energy Association, the installed capacity of wind power increased by 29 % from the end of 2007 to the end of 2008 to total 121 GW, with over half the increase in the United States, Spain and China.[21] Doubling of capacity took about three years. The total installed capacity is approximately three to eight times that of the actual average power produced as the nominal capacity represents peak output; actual capacity is generally from 13[22]-40% of the nominal capacity.[23]
Solar power
The available solar energy resources are 3.8 YJ/yr (120,000 TW). Less than 0.02% of available resources are sufficient to entirely replace fossil fuels and nuclear power as an energy source. Assuming that our rate of usage in 2005 remains constant, we will run out of conventional oil in 40 years (2045), coal in 154 yrs (2159). In practice neither will actually run out, as natural constraints will force production to decline as the remaining reserves dwindle.[24][25][26]
In 2007 grid-connected photovoltaic electricity was the fastest growing energy source, with installations of all photovoltaics increasing by 83% in 2009 to bring the total installed capacity to 15 GW. Nearly half of the increase was in Germany, now the world's largest consumer of photovoltaic electricity (followed by Japan). Solar cell production increased by 50% in 2007, to 3,800 megawatts, and has been doubling every two years.[27]
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.[28] The largest photovoltaic installation in North America is the 18 megawatt Nellis Solar Power Plant.
Since 1991 the largest solar power plant has been the 354 megawatt Solar Energy Generating Systems, in the Mojave Desert in California, using parabolic trough collectors. Stirling Energy Systems is currently building a 500MW solar power plant using solar concentrators and Stirling engines with a 750MW plant also planned.
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.[3]
Geothermal
Geothermal energy is used commercially in over 70 countries.[29] In the year 2004, 200 PJ (57 TWh) of electricity was generated from geothermal resources, and an additional 270 PJ of geothermal energy was used directly, mostly for space heating. In 2007, the world had a global capacity for 10 GW of electricity generation and an additional 28 GW of direct heating, including extraction by geothermal heat pumps.[3][30] Heat pumps are small and widely distributed, so estimates of their total capacity are uncertain and range up to 100 GW.[29] Heat pump capacity factors are low since demand is seasonal.
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