Energy resources belong to the energy-carrier resources that can generate light, heat or power energies directly or through conversion. They have long been an indispensable production element and important material basis for promoting social progress and economic development as well as improving people's living conditions. The development and utilization of energy resources will continue to play a major role for a long time in the future.

The energy resources described in this chapter including coal, oil and natural gas, uranium and geothermals are unrenewable resources of wide applications, but their development varies in size and degree. Among them, coal and oil and gas belong to fossil fuels in solid, liquid and gaseous states respectively, and all are important raw materials for chemical industry. Chemically pure uranium in solid state is a hard silvery white metal. When used as a nuclear fuel, it is the main substance for nuclear fission in which energy is highly concentrated. Geothermals is a kind of heat resources from the interior of the Earth. It can directly provide heat energy and thermal water resources in forms such as natural vapor, hot water and hot brine, and is of wide uses.

China is one of the countries that first discovered and developed coal, oil and gas and geothermal resources. The mining of uranium started in the mid-20th century and has since developed rapidly.

(1) Development and utilization of energy resources in ancient times

As early as the Neolithic Age some 6,000 years ago, coal had been used for carving ornaments. In the Zhou Dynasty, warm springs started to be used for building bathing pools (e.g., the Huaqing Pool). Records of the Warring States described the distribution of coal in Sichuan and Shaanxi. In Sichuan, natural gas was used to boil brine water to extract salt. During the Han Dynasty, coal was used in substitution for wood as fuel for iron smelting. In Shaanxi and Gansu, oil shows were discovered and known to be combustible. Petroleum found its military uses in the Jin Dynasty. In the Tang Dynasty, coal began to be used for metallurgy in addition to its use as fuel for making pottery and porcelain. Besides, a number of geothermal springs were used for building bathing pools and medical treatment. The Song Dynasty was a period of development of technology, during which coal mining and coking technologies were much improved, and petroleum was specially used for making weapons besides its uses in lighting, lubrication, medicine and as a fuel. It was also anticipated that "this material (petroleum) will prevail in the world in future". "Zhuotong wells" were used to collect the natural gas, making an important change in the operation mode and tools used for gas exploitation. In the following dynasties, the mining scale of energy resources continued to expand, and the technology was making corresponding progress. China was once in a leading position in the world in the development and utilization of coal and natural gas, some of the techniques were spread to foreign countries and imitated there.

(2) Development of energy resources in modern times

From the mid-18th to the mid-20th centuries, owing to the "closed-door policy" of the feudal system and impacts of the long-term warfare, China experienced a slow development in the exploitation and utilization of energy resources, lagging much behind that of the world. The Jilong Coal Mine in Taiwan, China and Kaiping Coal Mine in Hebei built in 1878, which were the first to use mechanical mining technology, were of small scale and low productivity. Later, a number of coal mines were built successively in Northeast China, Hebei and other places, showing trends of development with a gradual increase in production. In 1936, an annual output of 39 million tons of coal was achieved. During the War of Resistance against Japan, the Japanese invaders occupied most of the coal mines and made predatory exploitation of coal. According to statistics, from 1937 to 1945 a total of 420 million tons of China's coal resources were plundered. Many coal mines were destroyed by the war, and production was suspended. In 1948, the annual output of coal was only 25.96 million tons. As for the development of petroleum, since the first oil well (at a depth of 200 m) of China was drilled in the Miaoli area (Taiwan, China) with mechanical drilling equipment and technology in 1878, a number of oil wells were drilled successively in Yanchang of northern Shaanxi (1907), Dushanzi of Xinjiang (1937) and Yumen of Gansu (1939), and new oilfields were found. Although their distribution was confined to the northwestern border, and the oilfields were small in size, a substantial amount of crude oil was produced. From 1878 to 1948, an accumulative total of 670,000 tons of crude oil was produced. The production of natural gas was concentrated in Sichuan Province, and the output was not very high.In 1949, the People's Republic of China was founded, which marked a new stage for the development of China's energy resources. The exploration and development of coal, oil and gas were carried out systematically in a large scope. Old coal mines and old oil/gas fields were reconstructed and expanded, while new ones were successively discovered and built. The rapid increase of reserves brought about the increase of production. The output of coal jumped to the leading position in the world, that of petroleum strode into the ranks of the world's major petroleum-producing countries, and that of natural gas was increasing year by year. Since the initiation of exploration and development of uranium resources in 1955, a series of uranium deposits were found, forming a complete system of uranium mining and processing. The development of geothermal resources expanded from the early scattered geothermal spots to a coverage over most of the provinces, cities or regions, with a wide scope of applications. In short, the development of China's modern energy resources over the 40-odd years has been most fruitful and remarkable.