What is Geothermal Electricity?

Geothermal power generation is a new power generation technology that uses underground hot water and steam as power sources. Its basic principle is similar to that of thermal power generation. It is also based on the principle of energy conversion. First, geothermal energy is converted into mechanical energy, and then mechanical energy is converted into electrical energy. Geothermal power generation is actually an energy conversion process or geothermal power generation that converts underground thermal energy into mechanical energy, and then converts mechanical energy into electrical energy.

Chinese name: Geothermal power
Power source: Underground hot water and steam

Nature: New generation technology
Principle: Energy conversion

Geothermal power historical background

In 1904, Ladreiro, Tuscany, Italy, used geothermal power to drive a small 0.75-horsepower small generator for the first time, and provided five 100-watt electric lamps for lighting. Thermal power station.

Geothermal energy is renewable thermal energy from the depths of the earth, which originates from the decay of molten magma and radioactive material on the earth. The circulation of deep groundwater and the intrusion of magma from extremely deep ground into the crust bring heat from deep underground to near surface. The geothermal energy reserves are more than the total amount of energy used by people, and most of them are distributed around the edges of tectonic plates. Geothermal energy is not only pollution-free clean energy, but if the rate of heat extraction does not exceed the rate of supplementation, then

Geothermal power Thermal energy is also renewable.

With the shortage of fossil energy and the increase of environmental pressure, people pay more and more attention to the purification of renewable green energy, but geothermal energy has been used by humans long ago. As early as the 1940s, Prince Piero Ginoni Conti of Italy first used natural geothermal steam for power generation in Ladreiro. Geothermal power is produced by injecting water into rock formations using hydraulic or blasting methods to generate high-temperature water vapor, which is then pumped out of the ground to drive the turbine to rotate, thereby generating electricity. In this process, a part of the unused steam or exhaust gas is treated by the condenser to reduce the water back to the ground and circulate back and forth. In short, geothermal power generation is actually an energy conversion process that converts underground thermal energy into mechanical energy, and then converts mechanical energy into electrical energy. For geothermal resources with different temperatures, there are four basic power generation methods for geothermal power generation, namely direct steam power generation, expansion (flash evaporation) power generation, intermediate media (double-cycle) power generation, and full-flow cycle power generation.

Geothermal power generation has a history of nearly 100 years. New Zealand, the Philippines, the United States, Japan and other countries have all invested in the tide of geothermal power generation. Among them, the installed capacity of geothermal power generation in the United States ranks first in the world. In the United States, most geothermal generating units are concentrated in the Geysers geothermal power station. The Gaithers Geothermal Power Station is located in the Sonoma area about 20 kilometers north of San Francisco, California. Thermal displays such as hot spring clusters and fumaroles were discovered in the area in 1920. Multiple geothermal wells and multiple turbo-generator units were invested in 1958. By 1985, the installed capacity of the power station had reached 1361 MW. In the early 1970s, with the support of the State Science and Technology Commission, a large number of geothermal power stations emerged throughout China.

Geothermal Power Generation

The geothermal resources developed are mainly of steam type and hot water type. Therefore, geothermal power generation is also divided into two categories.

There are two types of geothermal steam power generation: primary steam method and secondary steam method.

Geothermal power generation steam method

The primary steam method directly uses the underground dry saturated (or slightly superheated) steam, or uses steam separated from the steam and water mixture to generate electricity.

Geothermal power secondary steam method

The secondary steam method has two meanings. One is not to directly use the dirty natural steam (primary steam), but to let it vaporize and clean through the heat exchanger.

Geothermal power Water, and then use clean steam (secondary steam) to generate electricity. The second meaning is that the high-temperature hot water separated from the first steam-water is decompressed and expanded to produce secondary steam, the pressure is still higher than the local atmospheric pressure, and the primary steam enters the turbine to generate electricity.

The water in geothermal water cannot be directly sent to the steam turbine for work according to the conventional power generation method. It must be input into the steam turbine for work in the state of steam. For the generation of unsaturated underground hot water with a temperature lower than 100 ° C, the vacuum hot water is used to reduce the pressure of the underground hot water entering the expansion vessel to generate expansion steam that is lower than the local atmospheric pressure. Then the steam and water are separated, drained, Steam is charged into a steam turbine to perform work. This system is called a "flash steam system". The specific volume of low-pressure steam is very large, so the individual capacity of the gas turbine is greatly limited. But it is safer during operation. For example, chloroethane, n-butane, isobutane, and freon are used as intermediate working medium for power generation. Underground hot water is heated by a heat exchanger to quickly vaporize low-boiling substances. The generated gas is used to enter the generator for work and work. The subsequent working fluid is discharged from the steam turbine into the condenser, where it is cooled by the cooling system, and recondensed into a liquid working fluid for recycling. This method is called "intermediate working medium method", and this system is called "dual current system" or "dual working system". This kind of power generation method is relatively insecure. If the power system is leaked slightly, accidents will easily occur after the working fluid escapes.

Geothermal power generation mixed steam method

In the mid-1990s, Israel's Ormat combined the above two systems of geothermal steam power generation and geothermal water power into one, and designed a new geothermal power generation system called combined cycle. Installation and operation in some countries in the world, the effect is very good.

Geothermal Steam Power System

Geothermal steam is used to drive the turbine to generate electricity. This system has mature technology and safe and reliable operation, and is the main form of geothermal power generation. Tibet Yangbajing Geothermal Power Station adopts this form.

Geothermal power generation double cycle power generation system

Also known as organic working fluid Rankine cycle system. It uses low-boiling organic matter as the working medium, so that the working medium obtains heat from the geothermal fluid in the flowing system, and generates organic steam, which in turn pushes the turbine to rotate and drives the generator to generate electricity.

Geothermal power generation full-flow power generation system

This system sends all the fluids of the geothermal wellhead, including all steam, hot water, non-condensable gases and chemical substances, etc. directly into the full flow without processing.

Geothermal power generation Expansion in a power machine performs work, which is then discharged or collected into a condenser. This form can make full use of the entire energy of the geothermal fluid, but it is technically difficult and is still being tackled.

Geothermal power dry hot rock power generation system

The idea of using underground hot dry rock to generate electricity was proposed by Americans Morton and Smith in 1970. In 1972, they drove two deep inclined wells of about 4,000 meters in northern New Mexico, injecting cold water from one well into a dry and hot rock mass, and taking out steam generated from the heating of the rock mass from another well, with a power of 2300 kW. Japan, the United Kingdom, France, Germany, and Russia have also conducted research on dry hot rock power generation, but no large-scale application has been made so far.

Geothermal power system utilization

The non-electrical use of geothermal energy abroad, that is, direct use, is very important. Because of geothermal power generation, thermal efficiency is low and temperature requirements are high. The so-called thermal efficiency is low. That is to say, due to different types of geothermal and different types of steam turbines, the thermal efficiency is generally only 6.4 to 18.6%, and most of the heat is consumed in vain. The so-called high temperature requirements, that is, the use of geothermal energy to generate electricity, the temperature requirements of underground hot water or steam, generally above 150 ; otherwise, it will seriously affect its economics. For the direct use of geothermal energy, not only the energy loss is much smaller, but also the temperature requirements for underground hot water are much lower. It can be used in a wide temperature range from 15 to 180 ° C. Among all geothermal resources, such medium and low temperature geothermal resources are very rich, much larger than high temperature geothermal resources. However, the direct use of geothermal energy also has its limitations. Due to the restriction of the distance between the heat transfer medium and hot water, generally, the heat source should not be too far away from the town or residential area where heat is used; otherwise, the investment is high and the loss is large. Poor economic performance cannot be achieved.

The direct utilization of geothermal energy has developed rapidly, and has been widely used in industrial processing, civil heating and air conditioning, bathing, medical treatment, agricultural greenhouses, farmland irrigation, soil heating, aquaculture, livestock and poultry breeding, etc.

Geothermal power In all aspects, it has received good economic and technical benefits and saved energy. The direct use of geothermal energy has lower technical requirements and simpler equipment. In a system that directly uses geothermal heat, although sometimes it can be used directly because of the low content of salt and sediment in the geothermal heat, it is usually pumped up by a pump and turned into hot gas through a heat exchanger. And hot liquid before use. These systems are the simplest and use conventional off-the-shelf components.

Most of the heat sources used in the direct use of geothermal energy are above 40 ° C. If heat pump technology is used, a hydrothermal source with a temperature of 20 ° C or lower can also be used as a heat source (such as the practice in the United States, Canada, France, Sweden, and other countries). The working principle of a heat pump is the same as that of a domestic refrigerator, except that the refrigerator is actually a unidirectional heat transfer pump, while a geothermal heat pump can transfer heat in both directions. In winter, it extracts heat from the earth and supplies it to the house or building (heating mode); in summer, it extracts heat from the house or building and then supplies it to the earth to store (air conditioning mode). Regardless of the circulation, the water is heated and stored, and it plays all or part of the function of an independent hot water heater.

Because electricity can only be used to transfer heat, it cannot be used to generate heat, so a geothermal pump can provide 3-4 times more energy than itself. It can be used over a wide range of earth temperatures. In the United States, geothermal pump systems are growing at an annual rate of 20%, and will continue to grow with a good double-digit growth momentum in the future. According to the United States Energy Information Administration, geothermal heat pumps will provide up to 68 Mt of oil equivalent energy for heating, cooling and water heating by 2030.

For geothermal power generation, if the temperature of the geothermal resource is high enough, a good way to use it is to generate electricity. The electricity generated can be supplied to the public grid,

Geothermal Power ---- Geothermal Pump It can also power local industrial processes. Under normal circumstances, it is used for basic load power generation, and only in special cases, is it used for peak load power generation. The reason is that first, it is difficult to control the peak load, and then there is the problem of scaling and corrosion of the container. Once the liquid in the container and the turbine is not full and the air enters, the problem of scaling and corrosion will occur.

Geothermal energy has a long history of being directly used in cooking, bathing and heating. Until now, natural hot springs and artificially mined underground hot water are still widely used by humans. According to UN statistics, the direct use of geothermal water in the world far exceeds geothermal power generation. China's direct use of geothermal water ranks first in the world, followed by Japan.

Geothermal water has a wide range of direct uses, including heating and air-conditioning, industrial drying, agricultural greenhouses, aquaculture, tourism hot springs and health care.

Main methods of geothermal power generation

Production process that converts underground thermal energy into mechanical energy, and then converts mechanical energy into electrical energy. According to the form of geothermal energy, its thermal energy can be divided into

Geothermal power Five types are steam type, hot water type, dry hot rock type, ground pressure type and magma type. From the perspective of geothermal energy development and energy conversion, the above-mentioned five types of geothermal resources can be used for power generation, but the steam-type and hot-water-type resources have been developed and utilized more recently. The advantages of geothermal power generation are: generally no fuel is required, and the cost of power generation is generally lower than hydropower, thermal power, and nuclear power in most cases, and the equipment is used for a long time. Impact, stable power generation, can greatly reduce environmental noise pollution, and so on.

There are two main methods of generating electricity using underground hot water: pressure reduction and expansion methods and intermediate medium methods:

Geothermal power generation step-down method

It is designed based on the principle of hot water vaporization temperature and pressure, for example, the water vaporization temperature is 68.7 at 0.3 absolute atmospheric pressure. By reducing the pressure, the hot water is boiled and turned into steam, so as to drive the turbine generator to generate electricity.

Geothermal Power Generation Intermediate Method

The dual-cycle system uses underground hot water to indirectly heat certain "low-boiling substances" to promote the power generation of steam turbines. For example, under normal pressure, the boiling point of water is 100 ° C, and some substances such as ethyl chloride and freon have boiling points under normal pressure of 12.4 ° C and -29.8 ° C, respectively. These materials are called "low boiling point substances". According to the boiling characteristics of these substances at low temperatures, they can be used as an intermediate medium for underground hot water power generation. Using the "intermediate medium" power generation method, both underground hot water (steam) above 100 ° C and underground hot water below 100 ° C can be used. For lower-temperature underground hot water, the "depressurization and expansion method" is relatively inefficient and technically difficult, and the "intermediate medium method" is more suitable.

Both methods have their own advantages and disadvantages. Geothermal power generation is still a new subject, and its people are still exploring.

Underground hot water often contains a large amount of corrosive gases, among which the most harmful are hydrogen sulfide, carbon dioxide, oxygen, etc., which are the main factors that cause corrosion. These gases enter the steam turbine, auxiliary equipment and pipelines, causing them to undergo strong corrosion. In addition, underground hot water contains scaling ingredients, such as silicon, calcium, magnesium, iron, etc., and gases that affect scaling, such as carbon dioxide, oxygen, and hydrogen sulfide. Compounds such as silicon oxide appear. Therefore, attention must be paid to solving the problems of corrosion and scaling in the use of underground hot water for power generation.

Geothermal Power Development Status

In the application of various renewable energy sources, geothermal energy appears to be relatively low-key. People pay more attention to the amount of solar energy from space, but ignore the rich resources given to human beings by the earth itself. Geothermal energy may become an important part of future energy. .

Compared to the instability of solar and wind energy, geothermal energy is a more reliable renewable energy source, which makes people believe that geothermal energy can be the best alternative energy source for coal, natural gas and nuclear energy. In addition, geothermal energy is indeed an ideal clean energy source, which has abundant energy resources and does not generate greenhouse gases during use.

Geothermal power generation status No harm to the global environment.

Geothermal energy use in the United States accounts for only 0.5% of the nation's energy composition. According to a report from the Massachusetts Institute of Technology, the existing geothermal system in the United States only collects about 3,000 megawatts of energy each year, and conservatively estimates that the recoverable geothermal resources reach 100,000 megawatts. Relevant experts pointed out that, given the corresponding attention and support of geothermal energy, in the next few years, geothermal energy is likely to become a new energy equivalent to solar energy and wind energy.

As with other renewable energy in its infancy, the biggest problems faced by geothermal energy in the industry came from technology and funding. The geothermal industry is a capital-intensive industry, and the process from investment to income is relatively long. Generally speaking, it is difficult to attract commercial investment. The development of renewable energy can generally be supported by preferential government policies, such as tax deductions, government subsidies, and the right to obtain preferential loans. Under the guidance of relevant preferential policies, investors will be more interested in investing in geothermal projects.

The utilization of geothermal energy at the technical level needs to be developed mainly for accurate survey of mining points and prediction of geothermal reserves. Due to the high cost of a single drilling operation, finding suitable mining sites is critical to the investment and construction of geothermal projects. The geothermal industry adopts the introduction of conventional energy survey equipment such as oil and natural gas to find accurate mining points for geothermal energy.

Other countries and regions in the world are also providing more convenience and support for the development of geothermal radon. About 40 countries around the world have put the development of geothermal energy on the agenda. It is expected that by 2010, the use of global geothermal resources will increase by 50%.

The biggest advantage of combined cycle geothermal power generation system is that it can be applied to high temperature geothermal fluid (including hot brine) for power generation greater than 150 , and the fluid after one generation of power enters duplex under the condition of not less than 120 Quality power generation system to perform secondary work, which is to make full use of the thermal energy of geothermal fluids, which not only improves the efficiency of power generation, but also reuses the tail water discharged after the primary power generation, which greatly saves resources.

According to statistics up to 1997, the installed capacity of geothermal power generation in the world has reached 7.622 million kw. The Gitongs Geothermal Power Station in the United States and California is the largest geothermal power station in the world before H, with an installed capacity of 918,000 kw. Tibet Yangbajing Geothermal Power Station is the largest geothermal power station in China, with an installed capacity of 25,200 kw.

Geothermal Power World

Geothermal power generation in the world will increase by 50% in 10 years. According to figures released by the American Geothermal Energy Association (GEA), global geothermal power generation has increased by 50% in the past 10 years, and this new energy is serving 47 million people worldwide. 21 countries in the New World have developed geothermal power.

The global distribution of geothermal resources is mainly concentrated in three zones: the first is the Pacific Rim, the east is the west coast of the United States, the south is New Zealand, and the west is Indonesia, the Philippines, Japan, and Taiwan. The second is the Mid-Atlantic Ridge, most of which lies in the ocean and passes through Iceland at the northern end; the third is from the Mediterranean to the Himalayas, including Italy and Tibet, China.

Globally, due to the uneven distribution of geothermal resources, geothermal utilization in different countries is also different.

United States

Researchers from the Geothermal Laboratory of the Southern Methodist University in the United States recently found that geothermal power generation capacity in the United States exceeds 3 million megawatts, which is 10 times that of coal. Statistics from the American Geothermal Resources Association show that the total amount of electricity generated by geothermal power in the United States is 2,200 MW, which is equivalent to the power generated by four large nuclear power plants. Although the geothermal resource reserves in the United States are surprisingly large, the utilization rate is less than 1%. The main reason is that the current geothermal development technology costs too much. On average, every mile (1 mile or 1.6 kilometers) drilled requires dozens of diamonds. Bits, and a bit costs at least $ 2,000, so geothermal development is relatively slow. ^[1]

Philippines

In the past, only high-temperature geothermal energy could be used as energy in the Philippines. With the development of science and technology, people can already use low-temperature geothermal energy for heating and cooling using heat pump technology. The Philippine government's preferential policies for renewable energy projects include tax incentives and tax exemptions. In 2008, geothermal energy accounted for 17% of the Philippines' total energy output, with a total installed capacity of 2 million kilowatts. In 2009, the government is in the process of bidding for 10 geothermal resource development projects, and there are also 9 collaborations being discussed directly with the company. These cooperations will develop a total of 620,000 kilowatts of geothermal energy.

Indonesia

The proven reserves of geothermal energy in Indonesia amount to 27 million kilowatts, accounting for 40% of the total global geothermal energy. The government strongly advocates the use of geothermal energy. The government has set targets for the use of diversified energy sources by 2025. Among them, the use of oil accounts for 20%, far below 52%, and the use of geothermal energy will increase to 5%. In order to accelerate the development and utilization of geothermal energy, Indonesia has not only issued a special government decree, but also actively attracted investment. In 2008, President Susilo announced the official launch of four thermal power plant projects with a total investment of US $ 326 million.

Iceland

All Iceland's electricity comes from clean energy such as hydropower and geothermal power. At the same time, the country has also established a complete geothermal utilization system and all heating systems also use geothermal energy. Utilizing geothermal heat can also help reduce carbon dioxide emissions. According to data from Iceland's National Energy Agency, if 646,000 tons of oil are used for heating every year, and geothermal is used to replace oil, Iceland can reduce carbon dioxide emissions by 40%. Thanks to the development of hydraulic and geothermal resources, Iceland has now become one of the cleanest countries in the world. ^[2]

Japan

As a volcanic island country, Japan has a geothermal resource of 23.47 million KW, making it the third largest geothermal resource country in the world. Since the nuclear power plant accident caused by the Great East Japan Earthquake, in order to ensure domestic power supply, Japan has significantly increased the import of overseas fuel resources. As international energy prices have risen, power companies have had to raise electricity prices. In order to alleviate the burden of electricity consumption of enterprises and residents, Japan has introduced the "Renewable Energy Act" to encourage independent power generation while accelerating the development and utilization of renewable energy such as geothermal power generation. ^[3]

Germany

Germany's first geothermal power plant will be completed. Germany's first geothermal power plant will be built as a local utility in the western German state of Baden-Württemberg. The German Ministry of the Environment was announced to invest 6.5 million euros for this. It is reported that the power plant will collect heat from a depth of 4600m underground. Due to the special geological structure of the area, the temperature of the underground rocks at this depth reaches 170 ° C.

Geothermal power development in China

Geothermal Power Generation in China

China's geothermal resources are mostly low-temperature geothermal, mainly distributed in Tibet, Sichuan, North China, Songliao and Northern Jiangsu. High-temperature geothermal energy for power generation

Yangbajing Geothermal Power Plant ^[4] The source is mainly distributed in Yunnan, Tibet, western Sichuan and Taiwan. It is estimated that there are 255 5,800MW of high-temperature geothermal heat in the Himalayas. There are 5 geothermal power stations operating with a total of 27.78MW so far. There is still a large amount of high and low temperature geothermal in China, especially the geothermal power in the western region needs to be developed.

China's most famous geothermal power generation is in Yangbajing Town, Tibet. Yangbajing Geothermal is located in Dangxiong County, 90 kilometers northwest of Lhasa. According to reports, there are large-scale fountains and geyser, hot springs, hot springs, boiling springs, hot water lakes, etc. The geothermal field covers an area of 17.1 square kilometers. It is the largest high-temperature geothermal wet steam field in China. The geothermal water temperature here is maintained at about 47 ° C. It is the first wet steam field developed in mainland China and the highest geothermal power station in the world. In the past, it was just a grassy pasture. The hot water emerging from the ground was flowing and the steam was transpiration day and night. In 1975, the Third Geological Brigade of Tibet used core drilling to drill China's first wet steam well in Yangbajing. The first year in mainland China, the first megawatt-scale geothermal generating unit successfully produced electricity here.

The Yangbajing geothermal power plant located deep in the Yangjing grassland of northern Tibet is currently the largest geothermal test base in China and the only power plant in the world that uses medium-temperature and shallow thermal storage resources for industrial power generation. At the same time, the Yangbajing geothermal power plant is still One of the backbone power sources of the Central Tibet Power Grid, the annual power generation accounts for 45% of the Lhasa Power Grid.

In July 2012, the National Development and Reform Commission issued the "Twelfth Five-Year Plan" for renewable energy development, stating that the estimated investment demand for renewable energy during the "Twelfth Five-Year Plan" period totaled approximately 1.8 trillion yuan. The development goal of the geothermal energy during the "Twelfth Five-Year Plan" period is that by 2015, the total amount of geothermal energy development and utilization will reach 15 million tons of standard coal. Among them, the installed capacity of geothermal power generation will strive to reach 100,000 kilowatts, and shallow geothermal energy buildings will provide heating The cooling area has reached 500 million square meters. ^[5]

Geothermal power promotion industry method

Reviewing the situation, to promote the healthy development of China's geothermal industry, we need to start from the following four aspects: ^[6]

The first is to rationally plan the development and utilization of geothermal resources to guide and standardize industrial development. Although geothermal energy resources are renewable resources, regeneration requires certain conditions and cannot be infinitely regenerated. To maintain the long-term stability of energy and allow the people to enjoy the blessings of nature forever, we must give priority to economical safeguards and make overall plans, and vigorously advocate the development model of "development under protection, protection under development". This requires relevant departments to do a good job in planning the geothermal industry's production capacity layout and industrial chain, focusing on breakthroughs in high-tech technology, and avoiding the geothermal industry chain blindly focusing on links with low technological content, resulting in local overcapacity, The overall competitiveness of the industry is not strong. At the same time, in the national development plan, indicators such as the utilization ratio of geothermal resources and the proportion of geothermal resources in energy consumption should be specified and combined with energy conservation and emission reduction goals. In addition, it is necessary to coordinate the development plans of local governments and related plans for geothermal development so as to keep them consistent with the overall national plan, and to avoid blind government projects and excessive investment. ^[6]

The second is to actively carry out exploration and evaluation of shallow geothermal energy resources to promote sustainable industrial development. Geothermal energy, especially shallow geothermal energy resources, which method is used for development, the amount of possible use, and the degree of impact on the environment after long-term use are subject to specific local hydrogeological conditions (groundwater burial conditions, stratum structure, and permeability of aquifers) , Groundwater quality, etc.) Only when these conditions are clearly identified can a correct choice be made for the use of shallow geothermal energy. Therefore, it is necessary to start from the key cities in the plain area at present, and carry out the survey and evaluation work with the accuracy of 1: 100,000 scale as the main body. Based on the results of the original hydrogeological survey, supplement the necessary survey work to obtain parameters such as thermal conductivity and permeability of rock and soil. Based on the survey and evaluation, develop a shallow geothermal energy development and utilization plan, make a reasonable layout, determine the areas suitable for development and utilization, delineate the areas of different utilization methods (groundwater, buried pipes), propose a reasonable development and utilization scale, and prevent geological Measures for disasters and environmental geology. ^[6]

The third is to create a good policy environment to support the development of the geothermal industry. The development and utilization of geothermal energy, especially shallow geothermal energy, has a high initial investment, but has low operating and management costs and features clean, efficient, and energy-saving. It is a clean energy with good development prospects and sustainable use. To this end, the government can reduce the initial capital cost of geothermal industry development by establishing preferential policies such as special funds for geothermal energy resources, subsidies, investment tax rebates, or production tax reductions. Of course, considering the sustainable development of the geothermal industry, these support measures must be appropriate and timely, and different preferential measures must be adopted according to the industrial development cycle, so as to promote the development of the geothermal industry from relying on policy support to mature industries with their own competition mechanisms. In addition, we must rationalize the system and mechanism, strengthen the organization and coordination of various government departments, and establish a good institutional environment. ^[6]

Fourth, increase technological innovation in geothermal development and utilization, and improve the technical support system. It is necessary to establish a national R & D platform as soon as possible, strengthen technological research and development work to improve innovation capabilities; include the effective use of geothermal resources in the industrial development and scientific research programs of governments at all levels, increase investment, and include budgets; Establish strategic partnerships, establish innovation alliances, and enable innovation to cover all important links in the entire industrial chain; formulate relevant technical standards and specifications, and regulate the development and utilization of geothermal energy resources; technically absorb foreign successful advanced experience (such as mining And re-irrigation technology, power generation and heat utilization technology), the introduction of heat pump technology for low and medium temperature geothermal utilization, to realize the cascade comprehensive utilization of geothermal resources, improve the utilization of geothermal energy, and then protect the ecological balance and achieve sustainable development. ^[6]

Geothermal power development prospects

International Online News: Energy experts believe that environmentally friendly geothermal power generation will have strong development prospects in the future. Swiss energy scientist Willie Gehl even believes that geothermal power generation will account for 10% of the world's total power generation in 20 years.
According to German media reports on May 17, a new geothermal power generation method advocated by Geer is called the "hot dry rock process method". Compared with methods that only extract thermal energy from hot springs in areas with frequent volcanic activity, this "hot dry rock process" will not be geographically restricted and can be exploited anywhere. The water is first forced into a depth of 4 to 6 kilometers by a pressure pump, where the temperature of the rock layer is about 200 degrees. Water is heated in high-temperature rock formations and is pumped through the pipeline to the surface for extraction into a heat exchanger. The heat exchanger drives the turbo-generator to convert thermal energy into electrical energy. After the hot water that drives the steam turbine is cooled, it is re-entered underground for recycling.
"The first commercial power plant to generate electricity using this new method will be completed in five years in the Swiss city of Basel. The power plant will be able to provide 30 MW of thermal energy and 3 MW of electricity to 5,000 homes in the surrounding area," Geer said. Geer emphasized that the cost of this geothermal power generation is competitive with that of other renewable energy sources, and that this method does not generate pollution such as waste water and waste gas during the power generation process, so it is a future new energy source. . Another benefit is that geothermal is almost inexhaustible and can be used anytime, anywhere.
The energy expert also pointed out that compared with technical issues, the extensive use of geothermal energy is a matter of awareness. "We know we are sitting on an almost inexhaustible source of energy. We are unwilling to dig a few kilometers under our feet and prefer to carry back oil, gas and coal from thousands of kilometers away." ^7]