This paper aims to predict the future situation of global energy development. In view of this, we reviewed the history of energy use and understood that new energy sources will usher in a new era following oil & gas, coal and wood one after another in the past time. Although the fossil energy sources are still plenty in the world, great breakthroughs made in some key technologies and the increasing demand for ecological environmental protection both impel the third time of transformation from oil & gas to new energy sources. Sooner or later, oil, gas, coal and new energy sources will each account for a quarter of global energy consumption in the new era, specifically speaking, accounting for 32.6%, 23.7%, 30.0% and 13.7% respectively. As one of the largest coal consumer, China will inevitably face up to the situation of tripartite confrontation of the coal, oil & gas and new energy. The following forecasting results were achieved. First, the oil will be in a stable period and its annual production peak will be around 2040, reaching up to 45 × 108 t. Second, the natural gas will enter the heyday period and its annual production peak will be around 2060, reaching up to 4.5 × 1012 m3, which will play a pivotal role in the future energy sustainable development. Third, the coal has entered a high-to-low-carbon transition period, and its direct use and the discharged pollutants will be significantly reduced. In 2050, the coal will be dropped to 25% of the primary energy mix. Last, the development and utilization of new energy sources has been getting into the golden age and its proportion in the primary energy mix will be substantially enhanced. On this basis, we presented some proposals for the future energy development in China. At first, we should understand well that China's energy production and consumption has its own characteristics. Under the present situation, we should strengthen the clean and efficient use of coal resources, which is the key to solving our energy and environmental issues. Then, under the low oil price circumstance, we should keep 200 million tons of annual oil production as “the bottom line” so as to ensure national energy security and to accelerate tight gas, shale gas and other unconventional resources development. In 2030, the annual natural gas production will reach up to more than 300 Bcm. Finally, the development and utilization of new energy resources should be further strengthened and non-fossil energy sources will be expected to reach as high as 20% of the primary energy consumption by 2030.
Humans convert energy from forms that are less desirable to those that are more desired i.e. from grass to meat, from wood to heat and from fossil fuels to electricity. Throughout history, man has developed ways to expand his ability to harvest energy. The primitive man found in East Africa 1,000,000 years ago, who had yet to discover fire, had access only to the food he ate so his daily energy consumption has been estimated at 2,000 Kcal or 2,000 dietary calories. Energy consumption of the hunting man found in Europe about 100,000 years ago was about 2.5 times that of the primitive man because he had better methods of acquiring food and also burned wood for both heating and cooking. Energy consumption increased again by almost 2.5 times as man evolved into the primitive agricultural man of about 5,000 years ago who harnessed draft animals to aid in growing crops. The advanced agricultural man of 1400 A.D. northwestern Europe again doubled the amount of energy consumption as he began inventing devices to tap the power of wind and water, began to utilize small amounts of coal for heating and harnessed animals to provide transportation. The dawn of the age of industrialization, ushered in by the invention of the steam engine, caused a 3-fold increase in energy consumption by 1875. Among other things, the steam engine allowed man to unlock the Earth's vast concentrated storage deposits of solar energy - coal, gas and oil so he no longer was limited to natural energy flows. Whereas increases in energy consumption had been gradual throughout history, once industrialization occurred, the rate of consumption increased dramatically over a period of just a few generations. The technological man of 1970 in the U.S. consumed approximately 230,000 Kcal of energy per day [~115 times that of primitive man] with about 26% of that amount being electrical energy. Of that electrical energy only about 10% resulted in useful work while the remaining 16% was wasted by inefficiencies in electrical generation and transmission. The change in energy consumption patterns over time are shown in Figure 1 below.
Figure 1. Estimated Daily Consumption of Energy per Capita at Different Historical Points
Adapted from: E. Cook, "The Flow of Energy in an Industrial Society" Scientific American, 1971 p. 135.
If you look at how energy sources have changed over time, you will notice that the age of industrialization and to an even greater extent the age of technology have accelerated the appearances and exploitation of new energy sources.
History of Energy Use in the United States
.The history of energy use in the U.S. stretches from the end of the advanced agricultural man era up to the modern technological man era. Wood was the predominant energy resource used in the U.S. until being replaced by coal in about 1885. The emergence of coal was fueled by westward expansion and the railroad. As railroads moved west away from the east coast and its abundant forests, they could no longer rely on wood to fuel their steam locomotives. Coal became the fuel of choice because it possessed higher energy content than wood and significant deposits could be found along the paths of the rail lines. In addition, iron and steel were needed to produce the rails and spikes needed. Coal proved an economical source of the coke need to produce the iron and steel. During the last half of the 19th Century the energy consumption for transportation and industry grew in a concerted fashion fueled by coal. Coal remained king until after World War II when petroleum surplanted it. The railroads switched to diesel locomotives and trucking fleets that used gasoline and diesel became the predominant form of goods transportation. Labor issues and safety standards which increased the costs of producing coal also played a role in coal's decline. However, coal fired electical generation allowed coal to remain an important energy resource.The emergence of petroleum and natural gas as predominant sources of energy followed an interesting pathway. These resources found little use for a number of decades after Edwin Drake's first successful drilling project. The use of petroleum began to increase in the 1920s, held steady during the depression and then increased dramatically until 1973, the time of oil embargos. No other energy source has ever shown such a meteoric rise in consumption as petroleum and natural gas. The changing picture of energy consumption by resource is shown in Figure 2.
Figure 2. U.S. Energy Consumption By Energy Resource 1635-2000 [in Quadrillion Btu]
Source: //www.eia.doe.gov/emeu/aer/eh/intro.html
In the 1970's and 80's hydroelectric and nuclear resources began to become more important. By the year 2000, we had moved away from absolute predominance of one particular resource to a complex mix of fossil fuels, hydroelectric and nuclear resources although fossil fuels still far exceeded any other source. Figure 3 shows the role of different energy sources used for energy production in 2000.
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