Comprehensive evaluation of the hottest new energy

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Comprehensive evaluation and analysis of new energy and wind power development

mentioning new energy, a familiar term, is the current goal of developing a low-carbon economy. People generally call solar energy, hydropower, wind energy, biomass energy, geothermal energy and other renewable energy as new energy. In fact, such a title is not accurate. Our ancestors used all the above-mentioned energy for thousands of years. For example, the firewood and charcoal used by our ancestors for cooking and heating, as well as soybean oil used for lighting, are the use of biomass energy; The drying of crops and food is the use of solar energy; Waterwheel pumping and grinding process grain, is the use of water energy; In ancient times, the main means of transportation sailboats used wind energy, and the windmills that pumped water also used wind energy. It was still wind energy to separate grain particles from debris; In Tang Dynasty, Yang Guifei's hot spring used geothermal energy to wash and coagulate grease. It can be seen that new energy is not new. Only after the industrial revolution, with the invention of steam engine and internal combustion engine, coal, oil and natural gas, the main modern energy, have been gradually popularized and applied on a large scale. In the history of human civilization, it is only more than 200 years. When the use of these mineral energy has brought serious environmental pollution and climate disasters, people suddenly wake up, eagerly look for alternative energy, and pay more attention to the use of renewable energy. On the contrary, the energy that our ancestors have used for thousands of years has been crowned with the title of new energy

what is new energy? The strict definition should be: low-cost renewable clean energy. Low price, renewable, clean these three elements are indispensable. In fact, the existing hydropower, solar power and wind power do not fully meet the above three elements. Although the cost of hydropower generation is relatively low, there are high investment, long construction period, great impact on local geological environment of the river, and dam failure risk, which do not really meet the requirements of ecological environmental protection, safety and reliability. As for solar power generation, although it is a clean energy for users, there is serious pollution and huge energy consumption for silicon wafer manufacturers; The essence is the transfer of pollution and energy consumption sites, which cannot be regarded as clean energy by comprehensive measurement. Only wind power generation is indeed a renewable and clean energy, but at present, wind power generation is still in a dilemma of high investment, low efficiency and difficulty

according to the above analysis, hydropower generation in the future can be regarded as a satisfactory new energy only after changing the water energy utilization mode of large-scale river damming. Solar power generation can only be regarded as a clean and practical energy with universal use value after finding new materials with high photoelectric conversion efficiency, low cost and pollution-free production process. Wind power generation can only be regarded as a truly qualified new energy after vigorously reducing costs. In comparison, only wind power has the brightest prospect. Why do you say so? Because hydropower resources are limited, it is not only dependent on rivers, but also limited by geographical and geological conditions. Solar power generation is restricted by many factors, such as overcast clouds, rain and snow, season, night and so on. Only wind power generation has a wide range of applications, few constraints, common @12, sensor calibration and zeroing; It is the most promising renewable and clean energy because of its convenient measurement of standard weights

reviewing the human use of wind energy, we can say that it has a long history and remarkable results. Until thousands of years before the industrial revolution, wind energy has played a vital role in the history of human shipping and navigation. It can be said that wind energy has promoted the development and progress of human society. However, modern wind power generation is not as efficient as ancient sailboats; Because ancient sailboats, whether windy, windy, downwind or headwind, could move forward day and night; Modern windmills, however, are in an inoperable state for most of the year. Why does this happen? Starting from the history of modern wind power generation, we know that modern wind power generation relies on windmills, that is, the common three propeller horizontal axis windmills. In fact, the earliest use of windmills was not to generate electricity, but to pump water. No matter in ancient China, or in European countries such as the Netherlands and Denmark, windmills were first used to pump water. However, in ancient China, the vertical axis resistance type sail windmills were used, while the horizontal axis lift type paddle windmills were used in European countries. It's really the same way to go. For the same purpose of pumping water, people have been using it leisurely and rarely for hundreds of years. It was not until Europeans took the lead in using windmills for power generation that people placed greater expectations on windmills. In order to speed up the windmill speed and improve the power generation efficiency, the methods of reducing the number of blades, increasing the length of blades and reducing the area of blades are adopted to try to reduce the resistance of blades and increase the tip speed ratio of blades

the windmill after growth achieved the goal of increasing power generation, but paid the price of reducing the breeze performance and wind hour utilization. Fortunately, the wind speed in the maritime climate of the Nordic countries is larger and more stable, so the advantages of such improvement outweigh the disadvantages. With the windmill gradually developing towards large-scale and super large-scale, due to the limitation of blade materials, in order to increase the tip speed ratio and sweeping area of the blade and reduce its own weight, the blade can only be designed into a thinner and longer hollow structure, and finally become a modern style of one rod and three needles

at present, a large number of popular three propeller horizontal axis windmills are designed by Westerners by applying aerodynamic principles and referring to helicopter propeller theory. The principle is: according to Bernoulli equation, at both ends of the fluid velocity change interface, the total energy of the fluid is conserved. The sweep interface of windmill blade is regarded as the interface of fluid velocity change to design the blade. When such a theory is applied to the design of small windmills, because the rotation speed of small windmills is very high, there are still some references based on this theory; However, when applied to the design of large windmills, it is obviously inappropriate to still use this theory as the design basis; Because the rotation speed of large windmills is very low, the sweeping interface of blades can no longer be regarded as the interface of fluid velocity changes. In fact, there is an essential difference between the aircraft propeller and the windmill blade, because the aircraft propeller rotates actively at high speed and the windmill blade rotates passively at low speed. The two are fundamentally different concepts and should not adopt the same design concept

why do Westerners conclude that the efficiency of horizontal axis windmills is higher than that of vertical axis windmills? It should be said that there is an experimental basis. Early Westerners must have carried out wind tunnel comparative tests, and such wind tunnel comparative tests are likely to use small windmills. Due to the high speed of the small windmill, the wind interception efficiency of the horizontal axis windmill blade is not affected at high speed, but more beneficial, and the efficiency is certainly high. When the speed of the small vertical axis windmill is relatively high, the wind interception efficiency of the blade decreases with the increase of the speed, and the resistance on the windward side increases instead. Moreover, in the early stage of small fans, coaxial direct drive motors were widely used, and the horizontal shaft windmills with high speed were obviously dominant; It is conceivable that in such early comparative tests, it is inevitable to conclude that the efficiency of horizontal axis windmills is higher than that of vertical axis windmills

we know that Westerners are very rigorous, sometimes too rigid, and their thinking is often bound by theory. Don't you know: even if the early theory is right, the later situation has changed. With the windmills becoming larger and larger, their rotation speed is getting lower and lower. The advantages of horizontal axis windmills are weakened in large windmills, but their disadvantages are strengthened. However, due to the low speed of the large vertical axis windmill, the original disadvantages and shortcomings are obviously weakened. Therefore, we cannot use western wind power theory and early verification conclusions to blindly deny that large-scale vertical can be completed in sequence after one setting; The application prospect of axial windmills

the larger the wind area is, the more wind energy is obtained, which is a basic common sense. Both ancient sailboats and modern gliders rely on increasing the wind area to obtain more wind energy. The modern windmill with one pole and three needles relies on the slender blades that rotate slowly to obtain wind energy, which is visually suspicious. But why is such basic common sense weak in front of modern windmill design theory? It is because people are shocked by the authoritative aerodynamic theory and blindly believe that such a design is reasonable, thinking that no matter how thin the three needles are, as long as the swept area of the blade is huge, wind energy will be obtained as efficiently as theoretically calculated. Don't you know that aerodynamics theory is used to analyze the structural force of objects moving at high speed in fluid. Although the shape design of the windmill blade is very in line with the requirements of aerodynamics, it is still difficult to play its due role in the case of low wind speed and slow rotation. Facts have proved that theory is divorced from practice, and even if authoritative theory is used in the wrong place, it will not produce ideal results. Just like the high-speed motor car running on the railway, its shape needs to be designed according to the aerodynamic structure; For ordinary trains, such a design is to paint the snake and add to the foot, which is useless. It seems that only those who are obsessed with western wind power theory will believe such a myth of self deception

although the three propeller horizontal axis windmill has been popularized and the technology is relatively mature, we cannot think that this is the best design without analysis because Westerners are also using this windmill

in fact, this kind of blade rotating perpendicular to the wind direction only uses limited lift, but loses greater axial resistance. Not only is the wind area of the blade itself too small, but also the lift type blade is very sensitive to wind direction disturbance and air eddy current. The distance between fans must be large enough to avoid mutual interference, which greatly reduces the installation density of windmills and the utilization of wind farm land, A large number of wind energy resources are unusable. Moreover, this kind of windmill can't operate normally in strong wind and windy hours. The annual utilization rate is less than 25%, and it becomes a decoration most of the time every year. This situation is due to both the windmill design itself and the low average wind speed in China, which cannot meet the original design requirements of the West. In short, the windmill with one pole and three needles is not in line with China's national conditions. Its massive popularity is a great loss and waste of existing wind energy resources, especially high-quality wind energy resources! It is the sadness of the wind power industry! This practice of blindly following western wind power technology has resulted in high investment, low efficiency, difficulty in combination and large waste of wind energy resources, which must be reversed as soon as possible! Encouraged by the subsidy policy of the state to vigorously support the development of new energy, it has stimulated people's enthusiasm and impulse for investment in wind power. Of course, there is nothing wrong with the original intention of the state to encourage the development of new energy, and Western countries also implement subsidy policies for wind power. Encouraged by the national subsidy policy, many wind power enterprises and local governments blindly participate in the wind power competition in the immediate interests, especially some large central enterprises, in order to compete for the thermal power quota, do not hesitate to lose money to participate in the wind power competition. The phenomenon of "Happy enclosure" and "Happy enclosure" occurs from time to time. It can be seen that the implementation of the subsidy policy has promoted the rapid development of wind power! But it masks the subsequent crisis and weakens the willingness and ability of wind power innovation

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