(文档含英文原文和中文翻译)
中英文翻译
英文原文
Historical Review of Solar Energy
Solar generally refers to the suns radiation energy. Carried out in the solar interior from H together into a helium the nuclear reaction, kept a huge release of energy, and continue to the space radiation energy, which is solar energy. This solar nuclear fusion reaction inside the can to maintain the hundreds of millions of first time. Solar radiation to space launch 3.8x10 ^ 23kW power of the radiation, of which 20 billionth of the Earths atmosphere to reach. Solar energy reaching the Earths atmosphere, 30% of the atmosphere reflectance, 23% of atmospheric absorption, and the rest to reach the Earths surface.
Its power of 80 trillion kW, that is to say a second exposure to the suns energy on Earth is equivalent to five million tons of coal combustion heat release. The average per square meter in the atmosphere outside the area of energy per minute to receive
about 1367w. A broad sense of the solar energy on earth many sources, such as wind energy, chemical energy, potential energy of water and so on. The narrow sense is limited to solar radiation of solar light thermal, photovoltaic and photochemical conversion of the directly.
At this stage, the worlds solar energy is still the focus of the study of solar energy power plant, but the diversification of the use of the condenser, and the introduction of flat-plate collector and a low boiling point working fluid, the device gradually expanded up to maximum output power 73.64kW, Objective To compare the clear and practical, cost remains high. The construction of a typical device are as follows: 1901, California built a solar-powered pumping devices, the use of truncated cone condenser power: 7.36kW; 1902 ~ 1908 years, built in the United States five sets of double-cycle solar-powered engines, the use of flat-panel collector and a low boiling point working fluid; in 1913,
Human use of solar energy has a long history. China more than 2000 years ago, back in the Warring States period, one will find that the use of four steel mirror to focus sunlight ignition; use of solar energy to dry agricultural products. The development of modern, solar energy has become increasingly widespread use, it includes the use of solar energy solar thermal, solar photovoltaic and solar energy use, such as the photochemical use. The use of solar photochemical reaction, a passive use (photo-thermal conversion) and the photoelectric conversion in two ways. A new solar power and renewable sources of energy use.
Silicon photovoltaic cells mainly in the absorption of solar light energy emitted by silicon photocell is mainly extracted from the sand by the development of Bell Labs. Solar energy is the internal or the surface of the sun sunspot continuous process of nuclear fusion reactions produce energy. Earths orbit on the average solar radiation intensity for the 1367w / ㎡. Circumference of the Earths equator to 40000km, and thus calculated the Earths energy can be obtained 173000TW. At sea level standard for peak intensity 1kw/m2, a point on the Earths surface 24h of the annual average radiation intensity 0.20kw / ㎡, which is equivalent to have 102000TW energy
Human dependence on these energy to survive, including all other forms of renewable energy (except for geothermal energy resources), although the total amount of solar energy resources is the human equivalent of the energy used by ten thousand times, but low energy density of solar energy, and it vary from place to place, from time to time change, the development and utilization of solar energy which is facing a major problem. These features will make solar energy in the integrated energy system
of the role of subject to certain restrictions.
The use of solar cells, through the photoelectric conversion to solar energy conversion is included in electricity, the use of solar water heaters, the use of solar heat hot water and use water for power generation, using solar energy for desalination. Now, the use of solar energy is not very popular, the use of solar power costs are high there, the problem of low conversion efficiency, but for satellite solar cells to provide energy has been applied.
Although the Earths atmosphere solar radiation to the total energy only 22 billionths of a radiation energy, it has been as high as 173,000 TW, that is to say a second exposure to the suns energy on Earth is equivalent to five million tons of coal. Earth wind energy, hydropower, ocean thermal energy, wave energy and tidal energy as well as some comes from the sun; even in the face of the earths fossil fuels (such as coal, oil, natural gas, etc.) that is fundamentally Since ancient times the storage of solar energy down, so by including a broad range of solar energy is very large,
he narrow sense is limited to solar radiation of solar light thermal, photovoltaic and photochemical conversion of the directly.
Solar energy is the first time, but also renewable energy. It is rich in resources, can use free of charge, and without transportation, without any pollution to the environment. For mankind to create a new life, so that social and human energy into a era of reducing pollution.
Solar cells have to respond to a light and convert solar energy to power the device. Photovoltaic effect can produce many kinds of materials, such as: single crystal silicon, polycrystalline silicon, amorphous silicon, gallium arsenide, copper indium selenium. They are basically the same principle of power generation is now crystal as an example to describe the process of light generation. P-type crystalline silicon available after phosphorus-doped N-type silicon, the formation of P-N junction.
When the surface of solar light, the silicon material to be part of photon absorption; photon energy transfer to the silicon atom, electronic transitions have taken place, as a free-electron concentration in the PN junction formed on both sides of the potential difference, when the external circuit connected when the effects of the voltage, there will be a current flowing through the external circuit have a certain amount of output power. The substance of this process are: photon energy into electrical energy conversion process.
Si is our planets abundance of storage materials. Since the 19th century,
scientists discovered the properties of crystalline silicon semiconductor, it almo st changed everything, even human thought, end of the 20th century. Our lives can be seen everywhere, silicon figure and role of crystalline silicon solar cells is the formation of the past 15 years the fastest growing industry. Production process can be divided into five steps: a, purification process b, the process of pulling rod c, slicing the process of d, the process of system battery e, the course package.
Solar photovoltaic
Is a component of photovoltaic panels in the sun exposure will generate direct current power generation devices, from virtually all semiconductor materials (eg silicon) are made of thin photovoltaic cells composed of solid. Because there is no part of activity, and would thus be a long time operation would not lead to any loss. Simple photovoltaic cells for watches and computers to provide energy, and more complex PV systems to provide lighting for the housing and power supply. Photovoltaic panels can be made into components of different shapes, and components can be connected to generate more power. In recent years, the surface of the roof and building will be the use of photovoltaic panels components,
Even be used as windows, skylights or sheltered part of devices, which are often called photovoltaic facilities with PV systems in buildings.
Solar thermal
Modern technology solar thermal polymerization sunlight and use its energy produced hot water, steam and electricity. In addition to the use of appropriate technology to collect solar energy, the building can also make use of the su ns light and heat energy is added in the design of appropriate equipment, such as large windows or use of the south can absorb and slowly release the sun heat the building materials .
According to records, human use of solar energy has more than 3,000 years of history. To solar energy as an energy and power use, only 300 years of history. The real solar as the near future to add much-needed energy, the basis of the future energy mix is the latest thing. Since the 20th century, 70s, solar technology has made rapid advances, solar energy use with each passing day. Solar energy utilization in modern history from the French engineers in 1615 in the Solomon and Germany Cox invented the worlds first solar-powered engines run. The invention is a use of solar energy heating the air to the expansion and pumping machines acting.
In 1615 ~ 1900, between the developed world and more than one solar power plant and a number of other solar energy devices. Almost all of these power plants
collect the sun means the use of condenser, engine power is not, the working fluid is water vapor, which is very expensive, not practical value, the majority of individual studies for manufacturing solar enthusiasts. 100 years of the 20th century, the history of the development of solar energy technology in general can be divided into seven stages.
1. The First Stage (1900---1920)
In this stage, the research focus of solar energy in the world were still on the device which variable photospot method were applied and flat plate heat collector and low boiling point actuating medium were started to use; the capacity of the device was gradually expanded with the max. output power of 73.46kW; device was utilized with the definite end-use and in higher cost.
The typical built device included: one set of pumping device constructed in California of U.S in 1901 which employed truncation taper photospot with the power of 7.36kW; 5 sets of twin-circulated solar-powered engine built in U.S in 1902 to 1908 which employed the flat plate heat collector and low boiling point actuating medium; 1 set of solar energy pump comprised of 5 parabolic mirror in a length of 62.5m, width of 4m built in Cairo of Egypt in which the total light collecting area could reach 1250m2.
2. The Second Stage (1920-1965)
For these 20 years, the research of solar energy was implementing on the poor stage, which the mandate to participate in the development and the research projects had been widely declined due to the mass utilization of fossil fuels and the second world war (1935---1945) while the s olar energy couldn’t satisfy the urgent demand upon the energy. Therefore, the research and development of solar energy was due to be gradually deserted.
3. The Third Stage (1945-1965)
For these 20 years after the Second World War, some foresight person has noticed that the petroleum and natural gas resources had been rapidly decreased and called for attention on these issues in order to gradually promote the recovery and development of the solar energy research. Solar energy institutes were setup and academic exchanges and exhibitions were held which raised the research upsurge again on solar energy.
In this period, great progress was achieved in the research of solar energy, in particular: the foundation theory of selective paints proposed in the First International Solar Thermal Academic Conference in 1955, which black nickel had been developed
as the practical selective paints, contributing to development of high-effective heat collector; the practical silicon solar cells developed by Bell Lab in U.S in 1954 which laid the foundation for large scale utilization of photovoltaic generation.
Furthermore, there were still other significant results, including:
a. One set of 50kW solar stove was built by French National Research Center in 1952;
b. The worldwide prototype ammonia-water absorbing air conditioning system heated by flat plate heat collector with the capacity of 5 tons was built in Florida of U.S in 1960;
c. An engine equipped with silicon window was invented in 1961.
In this stage, research on foundation theory and foundation material of solar energy was reinforced and academic breakthrough, i.e. selective paints and silicon solar cells were achieved. The flat plate had been well developed and ripe in technologies. Progress had been achieved in the research of solar energy absorbing air conditioners and a batch of pilot solar room was established. Preliminary research was conducted on the engine and tower type solar-powered generation technologies.
4. The Fourth Stage (1965---1973)
In the stage, the research work on solar energy was standstill due to the reason that the utilization technologies of solar energy had entered into the growing stage which was no ripe in process, heavy in investment and lower in effect. Thus it cannot compete with conventional energy, which resulted in the absence of attention and support from the public, enterprise and government.
5. The Fifth Stage (1973---1980)
After petroleum played a leading role in the worldwide energy structure, it has been a key factor to control the economic and determine the fatal, development and declining of a country. After the explosion of Middle East War at Oc., 1973, OPEC employed the method of declining the production and increasing the price to support the struggle and safeguard the national benefits which resulted in heavy economic attack for those countries that relied on importing large amount of inexpensive petroleum from the region of Middle East. Thus, some people in the western countries were frightened to call that the energy or petroleum crisis had been launched in the world. This crisis made people realized that the existing energy structure should be completely changed and transition to the future energy structure should be speed up.
From that on, many countries, especially the industrialized countries turned their attention towards the support on the research and development of solar energy and
other renewable energy technologies. The upsurge of developing and utilizing solar energy had been raised again in the world. In 1973, U.S drew up a government scale sunlight power generation program which the research budget for solar energy were increased in a large amount, and solar energy development bank was to established to facilitate the solar energy products to be commercialized. In 1974, Japan published the sunlight program made by the government, among which the solar energy development projects included solar room, industrial-use solar energy system, solar thermal generation, solar cells production system, scattered and large scale photovoltaic generation system. In order to implement this program, the government of Japan input large amount of manpower, material resources and financial resources.
The upsurge on the utilization of solar energy raised in 1970s in the world also impacted on China. Some foresight technicians started to devote to the solar energy industry one after another and positively proposed to the relative department of the government and published books and periodicals to introduce the international trends on the utilization of solar energy. Solar stove was popularized and utilized in countryside; solar water heater was launched in the city; solar cells used in space have started to be applied in the ground. In 1975, the first national solar energy utilization working exchanges conference held in An yang, Henan Province further promoted the development of solar energy industry in China. After this meeting, the solar energy research and promotion had been brought into the government program and awarded support of specialized fund and material. In some universities and institutes, solar energy task team and research departments were established one after another. Solar energy research institutes were also launched in some places. At that time, an upsurge on utilization of solar energy was emerging in China.
During this period, research and development of solar energy entered into an unprecedented well-developed stage with the following characteristics:
a. Each country enhanced planning on solar energy research. Many countries worked out short term and long-term sunlight program. The utilization of solar energy had been a governmental action with intensive support. The international cooperation was very active which some developing countries had started to participate in the utilization of solar energy.
b. The research field was expanding; research work was developed day by day and significant results achieved, for example, CPC, vacuum heat collecting pipe, non-crystal silicon solar cells, water-photolyzed hydrogen production and solar energy thermal power generation.
c. The solar energy development program worked out by each country existed the problems that the requirement was too high and urgent and insufficient expectation on difficulty in implementation. They have thought to replace the mineral energy in the short time and to utilize the solar energy in large scale. For example, U.S has once scheduled to build a small size solar energy demonstration satellite power station in 1985 and one set of 5 million kW space solar energy power station in 1995. In fact, this program has been adjusted in later, and the space solar energy power station has not yet been realized.
d. Products such as solar water heater and solar cells were started to commercialize. The solar energy sector has been preliminarily established with a small scale and ineffective economic effects.
6. The Sixth Stage (1980-1992)
The upsurge on utilization of solar energy emerged in 1970s was fallen into a stage of being developed in a low and slow step in 1980s. Many countries in the world declined the research budget for solar energy in successive in a large amount, in particular the U.S.
The main reasons resulted in this situation were that the international oil price was corrected in a large range while solar energy product cost was still remaining as before which may be of no competitive capability; no any significant breakthrough on solar energy technologies to increase the efficiency and reduce the cost which led to break down people’s confidence to develop solar energy; increased development on nuclear power which may restrain on a certain degree on the development of solar energy.
Influenced on the turndown of solar energy in the worldwide in 1980s, research work in China also declined in a certain degree. Due to the reason that the utilization of solar energy was heavy in investment, ineffective in results, difficult in energy storage and large in land covering, solar energy should be considered as the future energy. Some person even proposed that the technology could be introduced after it would be developed successfully. Only few people supported such viewpoint, but it was very harmful which will result in unfavorable influence on the development of solar energy industry.
During this period, although the research budget has been mitigated in a large amount, the research work remained uninterruptedly, among which some projects achieved progress which facilitated people to investigate seriously on the program and goads worked out before and to adjust the research focus so that to strive for great
achievement by less input.
7. The Seventh Stage (1992---Until Now)
Excessive burning of fossil fuel led to worldwide environmental pollution and ecological destruction, which has been threatened the substance and development of human beings. Under such circumstance, UN held the international environment and development conference in Brazil in 1992. On this meeting, a series of importan t document were published including the Environment and Development Manifesto, Agenda of 21st century and UN Framework Pact on Climate Changing in which the environment and development were brought into the integrated framework, and sustainable model was established. After this conference, each country enhanced the development of clean energy technologies, and developed the solar energy in line with the environmental protection so as to make the utilization of solar energy be well developed.
After this conference, Chinese government also turned their attention towards the environment and development and pointed out 10 pieces of tactic and measure definitely to develop and popularize the clean energy including solar energy, wind energy, thermal energy, tidal energy and biomass energy in accordance with the reality; worked out Agenda of 21st century in China and further focused the solar energy projects. In 1995, the State Planning, the State Economic and Trade Commission, the State Ministry of Science and Technology worked out the Outline for Development of New and Renewable Energy from 1996 to 2010, which definitely pointed out the goads, objectives and relative tactic and measure towards the development of new and renewable energy from 1996 to 2010 in China. The publishing and implementation of the document further promoted the development of solar energy industry in China.
In 1996, UN held the worldwide solar energy summit conference in Zimbabwe. The Solar Energy and Sustainable Development Manifesto was published after the meeting. Important document, i.e. Worldwide Solar Energy 10-Year Action and Program (1996---2005), International Solar Energy Pact , Worldwide Solar Energy Strategic Planning were discussed during the meeting. This meeting further showed eac h country’s commitment to developing the solar energy. Worldwide joint action was required to extensively utilize the solar energy.
After 1992, the worldwide utilization of solar energy has entered into a developing stage with the characteristic that:
a. The utilization of solar energy can be consistent to the sustainable development and environment protection, and can be carried out jointly to realize the
development strategy in the world;
b. Definite development goals with focus projects and effective measure, which will be favorable to overcome the shortage to ensure the long-term development of solar energy industry;
c. In the course of expanding the research of solar energy, attention was paid to convert the academic results into production, develop solar energy industry, speed up the progress to be commercialized, expand the utilization field and scale and increase the economic benefits;
d. Active international cooperation in the field of solar energy with expanding scale and obvious effect.
In view of the review, the development of solar energy in the 20th century was not so smooth. Generally speaking, low tide period was happened after every high tide period. The low tide period lasted for nearly 45 years. The development of solar energy differed with that of coal, petroleum and nuclear energy in understanding and development period, which could be demonstrated that it was very difficulty to develop the solar energy and it cannot be realized to large scale utilize in the short term. On the other hand, it was showed that the utilization of solar energy was also affected by the supply of mineral energy, politics and war. However, in a word, the solar energy has achieved greatly in academic results in 20th century than in any other century.
(文档含英文原文和中文翻译)
中英文翻译
英文原文
Historical Review of Solar Energy
Solar generally refers to the suns radiation energy. Carried out in the solar interior from H together into a helium the nuclear reaction, kept a huge release of energy, and continue to the space radiation energy, which is solar energy. This solar nuclear fusion reaction inside the can to maintain the hundreds of millions of first time. Solar radiation to space launch 3.8x10 ^ 23kW power of the radiation, of which 20 billionth of the Earths atmosphere to reach. Solar energy reaching the Earths atmosphere, 30% of the atmosphere reflectance, 23% of atmospheric absorption, and the rest to reach the Earths surface.
Its power of 80 trillion kW, that is to say a second exposure to the suns energy on Earth is equivalent to five million tons of coal combustion heat release. The average per square meter in the atmosphere outside the area of energy per minute to receive
about 1367w. A broad sense of the solar energy on earth many sources, such as wind energy, chemical energy, potential energy of water and so on. The narrow sense is limited to solar radiation of solar light thermal, photovoltaic and photochemical conversion of the directly.
At this stage, the worlds solar energy is still the focus of the study of solar energy power plant, but the diversification of the use of the condenser, and the introduction of flat-plate collector and a low boiling point working fluid, the device gradually expanded up to maximum output power 73.64kW, Objective To compare the clear and practical, cost remains high. The construction of a typical device are as follows: 1901, California built a solar-powered pumping devices, the use of truncated cone condenser power: 7.36kW; 1902 ~ 1908 years, built in the United States five sets of double-cycle solar-powered engines, the use of flat-panel collector and a low boiling point working fluid; in 1913,
Human use of solar energy has a long history. China more than 2000 years ago, back in the Warring States period, one will find that the use of four steel mirror to focus sunlight ignition; use of solar energy to dry agricultural products. The development of modern, solar energy has become increasingly widespread use, it includes the use of solar energy solar thermal, solar photovoltaic and solar energy use, such as the photochemical use. The use of solar photochemical reaction, a passive use (photo-thermal conversion) and the photoelectric conversion in two ways. A new solar power and renewable sources of energy use.
Silicon photovoltaic cells mainly in the absorption of solar light energy emitted by silicon photocell is mainly extracted from the sand by the development of Bell Labs. Solar energy is the internal or the surface of the sun sunspot continuous process of nuclear fusion reactions produce energy. Earths orbit on the average solar radiation intensity for the 1367w / ㎡. Circumference of the Earths equator to 40000km, and thus calculated the Earths energy can be obtained 173000TW. At sea level standard for peak intensity 1kw/m2, a point on the Earths surface 24h of the annual average radiation intensity 0.20kw / ㎡, which is equivalent to have 102000TW energy
Human dependence on these energy to survive, including all other forms of renewable energy (except for geothermal energy resources), although the total amount of solar energy resources is the human equivalent of the energy used by ten thousand times, but low energy density of solar energy, and it vary from place to place, from time to time change, the development and utilization of solar energy which is facing a major problem. These features will make solar energy in the integrated energy system
of the role of subject to certain restrictions.
The use of solar cells, through the photoelectric conversion to solar energy conversion is included in electricity, the use of solar water heaters, the use of solar heat hot water and use water for power generation, using solar energy for desalination. Now, the use of solar energy is not very popular, the use of solar power costs are high there, the problem of low conversion efficiency, but for satellite solar cells to provide energy has been applied.
Although the Earths atmosphere solar radiation to the total energy only 22 billionths of a radiation energy, it has been as high as 173,000 TW, that is to say a second exposure to the suns energy on Earth is equivalent to five million tons of coal. Earth wind energy, hydropower, ocean thermal energy, wave energy and tidal energy as well as some comes from the sun; even in the face of the earths fossil fuels (such as coal, oil, natural gas, etc.) that is fundamentally Since ancient times the storage of solar energy down, so by including a broad range of solar energy is very large,
he narrow sense is limited to solar radiation of solar light thermal, photovoltaic and photochemical conversion of the directly.
Solar energy is the first time, but also renewable energy. It is rich in resources, can use free of charge, and without transportation, without any pollution to the environment. For mankind to create a new life, so that social and human energy into a era of reducing pollution.
Solar cells have to respond to a light and convert solar energy to power the device. Photovoltaic effect can produce many kinds of materials, such as: single crystal silicon, polycrystalline silicon, amorphous silicon, gallium arsenide, copper indium selenium. They are basically the same principle of power generation is now crystal as an example to describe the process of light generation. P-type crystalline silicon available after phosphorus-doped N-type silicon, the formation of P-N junction.
When the surface of solar light, the silicon material to be part of photon absorption; photon energy transfer to the silicon atom, electronic transitions have taken place, as a free-electron concentration in the PN junction formed on both sides of the potential difference, when the external circuit connected when the effects of the voltage, there will be a current flowing through the external circuit have a certain amount of output power. The substance of this process are: photon energy into electrical energy conversion process.
Si is our planets abundance of storage materials. Since the 19th century,
scientists discovered the properties of crystalline silicon semiconductor, it almo st changed everything, even human thought, end of the 20th century. Our lives can be seen everywhere, silicon figure and role of crystalline silicon solar cells is the formation of the past 15 years the fastest growing industry. Production process can be divided into five steps: a, purification process b, the process of pulling rod c, slicing the process of d, the process of system battery e, the course package.
Solar photovoltaic
Is a component of photovoltaic panels in the sun exposure will generate direct current power generation devices, from virtually all semiconductor materials (eg silicon) are made of thin photovoltaic cells composed of solid. Because there is no part of activity, and would thus be a long time operation would not lead to any loss. Simple photovoltaic cells for watches and computers to provide energy, and more complex PV systems to provide lighting for the housing and power supply. Photovoltaic panels can be made into components of different shapes, and components can be connected to generate more power. In recent years, the surface of the roof and building will be the use of photovoltaic panels components,
Even be used as windows, skylights or sheltered part of devices, which are often called photovoltaic facilities with PV systems in buildings.
Solar thermal
Modern technology solar thermal polymerization sunlight and use its energy produced hot water, steam and electricity. In addition to the use of appropriate technology to collect solar energy, the building can also make use of the su ns light and heat energy is added in the design of appropriate equipment, such as large windows or use of the south can absorb and slowly release the sun heat the building materials .
According to records, human use of solar energy has more than 3,000 years of history. To solar energy as an energy and power use, only 300 years of history. The real solar as the near future to add much-needed energy, the basis of the future energy mix is the latest thing. Since the 20th century, 70s, solar technology has made rapid advances, solar energy use with each passing day. Solar energy utilization in modern history from the French engineers in 1615 in the Solomon and Germany Cox invented the worlds first solar-powered engines run. The invention is a use of solar energy heating the air to the expansion and pumping machines acting.
In 1615 ~ 1900, between the developed world and more than one solar power plant and a number of other solar energy devices. Almost all of these power plants
collect the sun means the use of condenser, engine power is not, the working fluid is water vapor, which is very expensive, not practical value, the majority of individual studies for manufacturing solar enthusiasts. 100 years of the 20th century, the history of the development of solar energy technology in general can be divided into seven stages.
1. The First Stage (1900---1920)
In this stage, the research focus of solar energy in the world were still on the device which variable photospot method were applied and flat plate heat collector and low boiling point actuating medium were started to use; the capacity of the device was gradually expanded with the max. output power of 73.46kW; device was utilized with the definite end-use and in higher cost.
The typical built device included: one set of pumping device constructed in California of U.S in 1901 which employed truncation taper photospot with the power of 7.36kW; 5 sets of twin-circulated solar-powered engine built in U.S in 1902 to 1908 which employed the flat plate heat collector and low boiling point actuating medium; 1 set of solar energy pump comprised of 5 parabolic mirror in a length of 62.5m, width of 4m built in Cairo of Egypt in which the total light collecting area could reach 1250m2.
2. The Second Stage (1920-1965)
For these 20 years, the research of solar energy was implementing on the poor stage, which the mandate to participate in the development and the research projects had been widely declined due to the mass utilization of fossil fuels and the second world war (1935---1945) while the s olar energy couldn’t satisfy the urgent demand upon the energy. Therefore, the research and development of solar energy was due to be gradually deserted.
3. The Third Stage (1945-1965)
For these 20 years after the Second World War, some foresight person has noticed that the petroleum and natural gas resources had been rapidly decreased and called for attention on these issues in order to gradually promote the recovery and development of the solar energy research. Solar energy institutes were setup and academic exchanges and exhibitions were held which raised the research upsurge again on solar energy.
In this period, great progress was achieved in the research of solar energy, in particular: the foundation theory of selective paints proposed in the First International Solar Thermal Academic Conference in 1955, which black nickel had been developed
as the practical selective paints, contributing to development of high-effective heat collector; the practical silicon solar cells developed by Bell Lab in U.S in 1954 which laid the foundation for large scale utilization of photovoltaic generation.
Furthermore, there were still other significant results, including:
a. One set of 50kW solar stove was built by French National Research Center in 1952;
b. The worldwide prototype ammonia-water absorbing air conditioning system heated by flat plate heat collector with the capacity of 5 tons was built in Florida of U.S in 1960;
c. An engine equipped with silicon window was invented in 1961.
In this stage, research on foundation theory and foundation material of solar energy was reinforced and academic breakthrough, i.e. selective paints and silicon solar cells were achieved. The flat plate had been well developed and ripe in technologies. Progress had been achieved in the research of solar energy absorbing air conditioners and a batch of pilot solar room was established. Preliminary research was conducted on the engine and tower type solar-powered generation technologies.
4. The Fourth Stage (1965---1973)
In the stage, the research work on solar energy was standstill due to the reason that the utilization technologies of solar energy had entered into the growing stage which was no ripe in process, heavy in investment and lower in effect. Thus it cannot compete with conventional energy, which resulted in the absence of attention and support from the public, enterprise and government.
5. The Fifth Stage (1973---1980)
After petroleum played a leading role in the worldwide energy structure, it has been a key factor to control the economic and determine the fatal, development and declining of a country. After the explosion of Middle East War at Oc., 1973, OPEC employed the method of declining the production and increasing the price to support the struggle and safeguard the national benefits which resulted in heavy economic attack for those countries that relied on importing large amount of inexpensive petroleum from the region of Middle East. Thus, some people in the western countries were frightened to call that the energy or petroleum crisis had been launched in the world. This crisis made people realized that the existing energy structure should be completely changed and transition to the future energy structure should be speed up.
From that on, many countries, especially the industrialized countries turned their attention towards the support on the research and development of solar energy and
other renewable energy technologies. The upsurge of developing and utilizing solar energy had been raised again in the world. In 1973, U.S drew up a government scale sunlight power generation program which the research budget for solar energy were increased in a large amount, and solar energy development bank was to established to facilitate the solar energy products to be commercialized. In 1974, Japan published the sunlight program made by the government, among which the solar energy development projects included solar room, industrial-use solar energy system, solar thermal generation, solar cells production system, scattered and large scale photovoltaic generation system. In order to implement this program, the government of Japan input large amount of manpower, material resources and financial resources.
The upsurge on the utilization of solar energy raised in 1970s in the world also impacted on China. Some foresight technicians started to devote to the solar energy industry one after another and positively proposed to the relative department of the government and published books and periodicals to introduce the international trends on the utilization of solar energy. Solar stove was popularized and utilized in countryside; solar water heater was launched in the city; solar cells used in space have started to be applied in the ground. In 1975, the first national solar energy utilization working exchanges conference held in An yang, Henan Province further promoted the development of solar energy industry in China. After this meeting, the solar energy research and promotion had been brought into the government program and awarded support of specialized fund and material. In some universities and institutes, solar energy task team and research departments were established one after another. Solar energy research institutes were also launched in some places. At that time, an upsurge on utilization of solar energy was emerging in China.
During this period, research and development of solar energy entered into an unprecedented well-developed stage with the following characteristics:
a. Each country enhanced planning on solar energy research. Many countries worked out short term and long-term sunlight program. The utilization of solar energy had been a governmental action with intensive support. The international cooperation was very active which some developing countries had started to participate in the utilization of solar energy.
b. The research field was expanding; research work was developed day by day and significant results achieved, for example, CPC, vacuum heat collecting pipe, non-crystal silicon solar cells, water-photolyzed hydrogen production and solar energy thermal power generation.
c. The solar energy development program worked out by each country existed the problems that the requirement was too high and urgent and insufficient expectation on difficulty in implementation. They have thought to replace the mineral energy in the short time and to utilize the solar energy in large scale. For example, U.S has once scheduled to build a small size solar energy demonstration satellite power station in 1985 and one set of 5 million kW space solar energy power station in 1995. In fact, this program has been adjusted in later, and the space solar energy power station has not yet been realized.
d. Products such as solar water heater and solar cells were started to commercialize. The solar energy sector has been preliminarily established with a small scale and ineffective economic effects.
6. The Sixth Stage (1980-1992)
The upsurge on utilization of solar energy emerged in 1970s was fallen into a stage of being developed in a low and slow step in 1980s. Many countries in the world declined the research budget for solar energy in successive in a large amount, in particular the U.S.
The main reasons resulted in this situation were that the international oil price was corrected in a large range while solar energy product cost was still remaining as before which may be of no competitive capability; no any significant breakthrough on solar energy technologies to increase the efficiency and reduce the cost which led to break down people’s confidence to develop solar energy; increased development on nuclear power which may restrain on a certain degree on the development of solar energy.
Influenced on the turndown of solar energy in the worldwide in 1980s, research work in China also declined in a certain degree. Due to the reason that the utilization of solar energy was heavy in investment, ineffective in results, difficult in energy storage and large in land covering, solar energy should be considered as the future energy. Some person even proposed that the technology could be introduced after it would be developed successfully. Only few people supported such viewpoint, but it was very harmful which will result in unfavorable influence on the development of solar energy industry.
During this period, although the research budget has been mitigated in a large amount, the research work remained uninterruptedly, among which some projects achieved progress which facilitated people to investigate seriously on the program and goads worked out before and to adjust the research focus so that to strive for great
achievement by less input.
7. The Seventh Stage (1992---Until Now)
Excessive burning of fossil fuel led to worldwide environmental pollution and ecological destruction, which has been threatened the substance and development of human beings. Under such circumstance, UN held the international environment and development conference in Brazil in 1992. On this meeting, a series of importan t document were published including the Environment and Development Manifesto, Agenda of 21st century and UN Framework Pact on Climate Changing in which the environment and development were brought into the integrated framework, and sustainable model was established. After this conference, each country enhanced the development of clean energy technologies, and developed the solar energy in line with the environmental protection so as to make the utilization of solar energy be well developed.
After this conference, Chinese government also turned their attention towards the environment and development and pointed out 10 pieces of tactic and measure definitely to develop and popularize the clean energy including solar energy, wind energy, thermal energy, tidal energy and biomass energy in accordance with the reality; worked out Agenda of 21st century in China and further focused the solar energy projects. In 1995, the State Planning, the State Economic and Trade Commission, the State Ministry of Science and Technology worked out the Outline for Development of New and Renewable Energy from 1996 to 2010, which definitely pointed out the goads, objectives and relative tactic and measure towards the development of new and renewable energy from 1996 to 2010 in China. The publishing and implementation of the document further promoted the development of solar energy industry in China.
In 1996, UN held the worldwide solar energy summit conference in Zimbabwe. The Solar Energy and Sustainable Development Manifesto was published after the meeting. Important document, i.e. Worldwide Solar Energy 10-Year Action and Program (1996---2005), International Solar Energy Pact , Worldwide Solar Energy Strategic Planning were discussed during the meeting. This meeting further showed eac h country’s commitment to developing the solar energy. Worldwide joint action was required to extensively utilize the solar energy.
After 1992, the worldwide utilization of solar energy has entered into a developing stage with the characteristic that:
a. The utilization of solar energy can be consistent to the sustainable development and environment protection, and can be carried out jointly to realize the
development strategy in the world;
b. Definite development goals with focus projects and effective measure, which will be favorable to overcome the shortage to ensure the long-term development of solar energy industry;
c. In the course of expanding the research of solar energy, attention was paid to convert the academic results into production, develop solar energy industry, speed up the progress to be commercialized, expand the utilization field and scale and increase the economic benefits;
d. Active international cooperation in the field of solar energy with expanding scale and obvious effect.
In view of the review, the development of solar energy in the 20th century was not so smooth. Generally speaking, low tide period was happened after every high tide period. The low tide period lasted for nearly 45 years. The development of solar energy differed with that of coal, petroleum and nuclear energy in understanding and development period, which could be demonstrated that it was very difficulty to develop the solar energy and it cannot be realized to large scale utilize in the short term. On the other hand, it was showed that the utilization of solar energy was also affected by the supply of mineral energy, politics and war. However, in a word, the solar energy has achieved greatly in academic results in 20th century than in any other century.