When will the earth's energy run out?

45-50 years for oil, 50-60 years for natural gas and 200-220 years for coal. If the world stops producing grain, the world grain reserve can only last for about 40 days. We can rest assured that the loss of resources is serious, but there will be new energy statistics. At present, 75% of the global energy comes from the burning of fossil fuels, which is the biggest pollution source of human health and the chief culprit of global greenhouse effect. Thermal power generation, transportation and various heating processes all need to burn a lot of coal, oil, diesel oil, gasoline and wood products. During the combustion process, these fossil fuels will release a large number of harmful gas particles, leading to respiratory disorders and cancer. Globally, one of the most serious environmental problems facing the world at present is the increasing content of greenhouse gases in the atmosphere, which is the most important reason for global climate change. The United Nations hopes that all countries in the world will vigorously develop and apply renewable energy sources, including solar energy, wind energy, geothermal energy, bioenergy and water resources, and at the same time increase technological upgrading and transformation of existing mineral energy sources to reduce harmful gas emissions. Scientists have found that there is a hot rock layer on the earth's surface with the temperature exceeding 1000 degrees for several kilometers. It is conceivable that the fiery magma ejected by volcanic eruption originated from this. Scientists call this heat energy a rock geothermal resource. If the thermal energy in hot rocks can be taken out and converted into electricity, rocks can also generate electricity. Before this, scientists have invented a method of generating electricity by using hydro-geothermal resources, that is, converting the energy of underground steam or hot springs into electric energy, which has accounted for 0.3% of the total power generation. How to extract heat energy from underground rocks to generate electricity is a long-term dream of many energy experts. Roya Dachscher, an anglo-Dutch oil company, is planning to turn this dream into reality. Not long ago, the company set up a geothermal consortium in El Salvador to solve the problem of rock geothermal resources utilization by using advanced technology. According to the consortium's rock geothermal development plan, engineers and technicians will use advanced exploration technology to find underground hot rocks in El Salvador, and then establish a water pressure injection system through drilling technology. Using this system, the cold water on the ground can go deep underground and be converted into hot water or superheated steam through hot rocks to return to the ground, thus obtaining heat energy. On the ground, heat energy is converted into electric energy. According to experts' accounting of Loyada Chishe Oil Company, they can build a rock geothermal power station with a power of 2,000-5,000 kilowatts. Daley, technical manager of Loda Cheshire Oil Company, said: "El Salvador Plan" is part of their company's grand plan for geothermal utilization. The company plans to invest $50-65.438+0 billion in the next five years to expand the scale of geothermal exploitation of rocks, so that the underground hot rocks will become one of the main energy sources of mankind in the near future. Solar scientists predict that during the period from 10 to 15, there will be a large number of solar thermal power plants in sunny areas of the earth, providing clean electricity for all countries in the world. At the beginning of the 20th century, researchers began to use the groove condenser on the roof to obtain energy: firstly, the oil in the black pipe was heated to 400 degrees Celsius, and when the oil flowed through the heat exchanger, the water was evaporated into steam, and then the steam was used to drive the turbine generator. With the passage of time, with the continuous efforts of researchers, solar power generation technology has been greatly improved. At present, the conversion efficiency of trough solar power generation has reached 15%, which means that the incident light energy of 1/6 can be converted into electric energy, while the conversion efficiency of solar panels can only reach 10%. In the late 1980s, American researchers built a 354 MW solar thermal power station in California, which is equivalent to a medium-sized thermal power station. However, the disadvantage of trough thermal power station is that it covers a large area. It needs a tank with a length of 150m and a width of 6m, and its power generation cost is three times that of coal, oil or natural gas. Trough power generation is not the only way of solar power generation, and some engineers have adopted other schemes, such as tower power generation. They use hundreds of single mirrors (heliostats) to track the sun from east to west. The mirror shines the solar beam on the heat exchanger at the top of the tower, and the heat exchanger introduces the absorbed heat into the salt solution. The heated salt solution is pumped to the bottom of the tower to generate steam to drive the turbine. Although the method of using salt solution is good, the solution will corrode pipes and containers. Therefore, scientists intend to use air instead of salt solution to conduct heat energy. In order to solve the problem of poor thermal conductivity of air, researchers have developed a "volume receiver", which is similar in principle to a water-absorbing sponge and can heat the air to 1200 degrees Celsius. When the hot air passes through the receiving system, the system absorbs most of the heat in the air and directly blows the heated air into the turbine to drive the turbine to generate electricity. Whether this scheme will replace the low-valley power generation scheme in the future is still inconclusive. Theoretically, the solar energy utilization rate of tower thermal power station can reach 25%. What is important is that there are still some technical problems in the tower thermal power station, and the trough power generation technology is mature. Last September, the Spanish government passed a new decree, which raised the original electricity price per kWh from 3 Euro cents to 15 Euro cents. To this end, Spain plans to build the largest solar trough thermal power station in Europe in 2004. In order to improve the utilization rate of solar energy, the researchers replaced the oil in the adsorption tube with water, which not only saved the expensive oil, but also directly evaporated the water. However, before the technical test of replacing oil with water was successful, oil was still used as the heat carrier in the adsorption tube. Judging from the current progress, this technology may be realized within five years, when the utilization rate of solar energy is expected to increase to more than 20%. In addition to the lower cost than solar panels, solar thermal power plants can still generate electricity by storing heat energy during the day after sunset. Storage of heat requires a storage tank or container filled with salt solution, which requires a large space. In the future, there will definitely be better media than the above-mentioned heat carrier, and it is only a matter of time before it is discovered.