geothermal

Geothermal energy is the heat energy contained in the earth. It is a clean, low-carbon, widely distributed, resource-rich, safe and high-quality renewable energy. It is usually divided into shallow geothermal energy, hydrothermal geothermal energy, and dry hot rock geothermal energy. The development and utilization of geothermal energy has the characteristics of sustainable and stable energy supply, efficient recycling and renewable, which can reduce greenhouse gas emissions and improve the ecological environment, and plays an important role in the development of clean energy in the future.

The uses of geothermal energy include power generation, building heating, bathing and recuperation, planting and breeding, baking, etc. Among them, the high-temperature geothermal heat above 150 ℃ is mainly used for power generation, and the hot water discharged after power generation can be used in steps. The medium temperature of 90 ℃ ~ 150 ℃ and the low temperature geothermal heat of 25 ℃ ~ 90 ℃ are mainly used directly, and are mostly used in industry, planting, breeding, heating and cooling, tourism recuperation, etc. The shallow ground temperature below 25 ℃ can be heated and cooled by land source and water source heat pump.

At present, the utilization of geothermal energy in China shows a trend of rapid development of shallow geothermal energy utilization, continuous growth of hydrothermal geothermal energy utilization, and rapid development of geothermal energy exploration, development and utilization equipment. It is worth noting that the exploration and development of hot dry rock geothermal energy resources in China is still in its infancy. Dry hot rock geothermal energy is an important field of geothermal energy development in the future.

ocean energy

Ocean energy is a kind of renewable energy contained in the ocean, including tidal energy, wave-induced mechanical energy and thermal energy. Ocean energy also involves a broader scope, including wind energy over the sea, solar energy on the surface of the sea and biomass energy in the sea.

Our country has a coastline of 18000 kilometres and 6960 islands covering a total area of 6700 square kilometres. Most of these islands are far from land and therefore lack energy supplies. Therefore, in order to achieve the sustainable development of China's coastal and island economy, we must vigorously develop China's marine energy resources.

Tidal energy refers to the potential energy generated during high and low tides. The intensity of tidal energy is related to the number of tidal heads and the drop. Tides with a tidal head drop of more than 3 meters usually have capacity utilization value. Tidal energy is mainly used to generate electricity.

Wave energy refers to the kinetic and potential energy contained in sea surface waves. Wave energy is mainly used to generate electricity, but it can also be used to transport and pump water, heat, desalinate seawater and produce hydrogen.

Ocean thermal energy refers to the heat energy caused by the temperature difference between the surface water body and the deep water body of the ocean. In addition to power generation, ocean thermal energy can also be used for seawater desalination.

coal bed gas

Coalbed methane, commonly known as "gas" and coal seam methane, refers to the hydrocarbon gas stored in coal seam with methane as the main component, adsorbed on the surface of coal matrix particles, partially free in coal pores or dissolved in coal seam water, which is the associated mineral resources of coal. Speeding up the development and utilization of coalbed methane (coal mine gas) is of great significance to ensure the safe production of coal mines, increase the supply of clean energy and reduce greenhouse gas emissions.

Generally, coal mine gas extraction concentration of more than 8% of the gas, can be used for power generation, civil or industrial production. The calorific value of coalbed methane is 2-5 times that of general-purpose coal. The calorific value of 1 cubic meter of pure coalbed methane is equivalent to 1.13kg of gasoline and 1.21kg of standard coal. Its calorific value is equivalent to that of natural gas. It can be mixed with natural gas, and it hardly produces any waste gas after combustion. It is a good chemical raw material, power generation and residential fuel.

From a global perspective, the global coal-bed methane resource with a depth of less than 2000 meters is about 240 trillion cubic meters. According to statistics, my country's coalbed methane geological resources rank third in the world, behind Russia and the United States, accounting for 12% of the world's total coalbed methane.

At present, there are many forms of clean and efficient utilization of coalbed methane, but the common ones are gas power generation, industrial gas, central heating, mechanical power, automobile power, household cooking and so on. In short, wherever natural gas is used, coal-bed methane can be used as a substitute.

Solar Energy

Solar energy generally refers to the radiant energy of sunlight, which is generally used for power generation in modern times. Solar power is a new renewable energy. In a broad sense, solar energy is the source of many energy on the earth, such as wind energy, chemical energy, water potential energy and so on. In billions of years, solar energy is an ideal energy source that can't be taken and used up.

The advantages of solar energy include:(1) universal, the sun shines on the earth, there is no geographical restriction, regardless of land or sea, regardless of mountains or islands, are everywhere, can be directly developed and utilized, and without mining and transportation. (2) harmless, the development and utilization of solar energy will not pollute the environment, it is one of the cleanest energy, in today's increasingly serious environmental pollution, this is extremely valuable. (3) Huge, the annual solar radiation energy reaching the earth's surface is equivalent to about 130 trillion tons of coal, which is the largest energy that can be developed in the world today. (4) For a long time, according to the current rate of nuclear energy generated by the sun, the storage of hydrogen is sufficient to maintain tens of billions of years, and the life of the earth is about billions of years. In this sense, it can be said that the energy of the sun is inexhaustible.

Shale gas

Shale gas is an unconventional natural gas that occurs in organic-rich shale and its interlayers, with adsorption and free state as the main mode of existence. Its composition is mainly methane, which belongs to the same category as coalbed methane and tight gas. The combustion of shale gas produces less pollution and is considered to be one of the main clean energy sources in the future.

The formation and enrichment of shale gas has its own unique characteristics, which is often distributed in the shale source rock strata with large thickness and wide distribution in the basin. Compared with regular natural gas, shale gas development has the advantages of long mining life and long production cycle. Shale gas has long been recognized, but it is more difficult to collect than traditional natural gas. With the increasing scarcity of resources and energy, as a useful supplement to traditional natural gas, people gradually realize the importance of shale gas.

China's shale gas resources are diverse and widely distributed. From the Proterozoic to the Quaternary, many sets of organic-rich shale systems have been formed in three sedimentary environments, namely, marine, marine and continental, which have great resource potential.

Shale gas, like natural gas, has a wide range of uses. It is mainly used in industrial production and living fields such as chemical fertilizer, chemical industry, power generation, ceramics, glass, machinery, light industry, metallurgical manufacturing and civil fuel.

biomass energy

Biomass energy refers to the energy form of solar energy stored in biomass in the form of chemical energy, that is, the energy based on biomass. Biomass can directly or indirectly replace the photosynthesis of green plants, and can be converted into regular solid, liquid and gaseous fuels. It is an inexhaustible and renewable energy, and it is also the only type of renewable carbon source.

So in a broad sense, biomass energy is a form of solar energy. As an important new energy, biomass energy has mature technology and wide application. It plays an important role in dealing with global climate change, alleviating the contradiction between energy supply and demand, and protecting the ecological environment. It is the fourth largest energy in the world after oil, coal and natural gas, and has become an important force in the international energy transformation.

According to different sources, biomass suitable for energy utilization can be divided into 5 categories, including forestry resources, agricultural resources, domestic sewage and industrial organic wastewater, municipal solid waste and livestock manure. The 13th five-year Plan for Biomass Energy Development issued by the State Energy Administration shows that the total amount of biomass resources such as crop straw and agricultural products processing residues, forestry residues and energy crops, domestic waste and organic waste that can be used as energy in the country is about 0.46 billion tons of standard coal per year.

natural gas hydrate

Natural gas hydrate, also known as "combustible ice", is a crystalline substance formed by gas molecules and water molecules at low temperature and high pressure. After decomposition into gas, the methane content is generally above 80%, up to 99.9. One cubic meter of combustible ice releases 164 cubic meters of methane gas and 0.8 cubic meters of water. Combustible ice will only produce a small amount of carbon dioxide and water after combustion, and will not release dust, sulfide, nitrogen oxides and other environmental pollutants like coal and petroleum products when burning, so it is known as the most ideal clean energy in the 21st century.

The formation of combustible ice requires a large amount of hydrocarbon gases. Some of these hydrocarbon gases come from the decomposition of microorganisms, some from the thermal degradation of deep oil and gas fields, and of course, they are formed by mixing the two. In this way, combustible ice can be divided into three types, namely, microbial gas type, pyrolysis gas type and mixed gas type.

Most of the combustible ice found in the sea area is microbial gas type, and the ones found in the northern South China Sea mainly belong to this type. The combustible ice found in the land area is mainly mixed gas type and pyrolysis gas type, such as the combustible ice found in the frozen soil area of Qilian Mountain in China. In general, the ratio of carbon isotopes can be used to determine the gas source of combustible ice.

Combustible ice has the characteristics of high combustion value, low pollution and large reserves, and is regarded as a strategic alternative energy source for oil and natural gas in the future.

Water energy

Water energy refers to the energy contained in natural water flow, mainly refers to the potential energy and kinetic energy of water. In a broad sense, hydropower resources include river water energy, tidal energy, wave energy, ocean current and tidal energy, etc. Tidal energy and wave energy are often referred to as new energy; in a narrow sense, hydropower resources refer to river water energy.

regular hydropower refers to the use of energy in the terrestrial water system. The basic principle is to use the potential energy of rivers, lakes and other water bodies located at high places. When the water falls to a low place, it drives a water turbine to convert the water potential. Energy is converted into kinetic energy, and then the generator is driven by the turbine to generate electrical energy.

A typical hydropower station consists of three parts: a reservoir that stores water, a dam that controls the flow of water, and a generator that generates electricity. Hydropower stations have the advantages of low power generation cost, high efficiency and flexibility, and can also form a comprehensive utilization system of water resources with flood control, irrigation, shipping, aquaculture, tourism and other aspects. In the process of converting water energy into electric energy, it does not change chemically, does not discharge harmful substances, and does not pollute the air and water itself, so it is an inexhaustible and inexhaustible clean energy.

Nuclear energy

Nuclear energy is a nuclear fuel made of uranium that fission in the "reactor" equipment to generate a large amount of heat energy, and then use water under high pressure to take out the heat energy, generate steam in the steam generator, and the steam drives the steam turbine to drive the generator to rotate together. And generate electricity, and send it to consumers through the power grid.

Compared with thermal power generation, nuclear power has the following characteristics: (1) Nuclear power generation is clean energy. Nuclear power plants do not emit harmful substances and will not cause the "greenhouse effect". (2) Nuclear power generation is an economical energy source. Although the investment in nuclear power plants is higher than that of coal-fired power plants, the total power generation cost of nuclear power plants is currently lower than that of coal-fired power plants due to factors such as the cost of nuclear fuel being lower than that of coal-fired power plants and the long-term role of nuclear fuel. Nuclear energy is a sustainable energy source. The world's proven uranium reserves of about 4.9 million tons, thorium reserves of about 2.75 million tons. These fission fuels are sufficient for the fusion energy era.

Wind energy

Wind energy is the kinetic energy generated by air flow and is a form of solar energy conversion. Due to the uneven heating of various parts of the earth's surface caused by solar radiation, the pressure distribution in the atmosphere is unbalanced. Under the action of the horizontal pressure gradient, the air moves in the horizontal direction to form wind.

The total reserves of wind energy resources are very large, and the energy that can be developed by technology in a year is about 5.3 × 1013 kW. Wind energy is a renewable clean energy with large reserves and wide distribution, but its energy density is low (only 1/800 of water energy) and unstable. Under certain technical conditions, wind energy can be developed and utilized as an important energy source. Wind energy utilization is a comprehensive engineering technology, which converts the kinetic energy of wind into mechanical energy, electrical energy and thermal energy through wind turbines.

It is estimated that although only about 2% of the solar energy reaching the earth is converted into wind energy, the total amount is still very considerable. The global wind energy is about 130 billion kilowatts, which is 10 times greater than the total amount of water energy that can be exploited on the earth.

Website Editor: Gong Li