The Retrospection for the Using of Solar energy:
It was recorded that, it has been more than 3000 yeas since human beings began to make use of solar energy. However, it was just for 300 years when the solar energy was being used as energy sources and different powers. And it wasn’t actually used as complemental energies for the recently urgent needs or fundation of the future energy struction until recent years.The solar powered technology had been advanced rapidly and the use of it also changed quickly since the 1970s. The first solar powered engine ,which was expanded by heating the atmosphere by solar energy to pump water, was invented by the France engineer Solomon.de.Cox in 1615 that started the use of solar energy in the modern history. People, all over the world, invented more solar powered devices and some other solar settings which almost been adopted the method to gather light by assembling it during the years from 1615 to 1900. Most of these settings mainly made by vapor, which were expensive with little practicality value and weak engine power, were invented by some enthusiasts who devoted themselves to the research and development of solar energy. The developing history of solar powered technology could be devided into seven phases during the 100 years from the 20th century , which were introduced respectively as follows:
The First Phase ( from 1900 -1920 )
Solar powered settings were still the key subject studied by global scientists but with diversity of ways of gathering lights during this phase. And people began to adopt flat plate collector and working medium of lower boiling point which made these settings enlarged gradually with the maximum output power of 73.64kw and a clear purpose in utility, but still with expensive prices. Here are some typical solar powered settings which had been created :A solar powered pump setting made in California, America in 1901 through using a truncated cone condenser made its power arrived at 7.36kw . During 1902 -1908, the Americans created five sets of solar powered engines which could circulate doubly, adopting the flat plate collector and working medium of lower boiling point. And people in the south Cairo in Egypt created a solar powered pump that made of five parabolic trough collectors, each of these collectors was within a length of 62.5m and a width of 4m. The total area for light-gathering arrived at 1250m2.
The Second Phase ( from 1920 -1945 )
The study of solar energy was at low tide during these decades. The mineral fuel was developed and used on a large scale together with the burst of the second world war during 1935-1945 resulted in the quantities of people who took part in the study and the studing items been reduced rapidly. What worse was that the solar energy couldn’t meet the needs of energy resources at that time ,thus making the study of solar energy been ignored gradually.
The Third Phase ( from 1945 -1965 )
During these twenty years after the end of the second world war, some individuals with foresight appealed to people’s recognition for the phenomenon as they realised the gradual reduction of the rock oil and natural gas. Therefore, the comeback and development on the study of solar energy had been promoted gradually which not only helped enable the establishment of the academic organization for solar energy but also the holding of the academic communications and exhibitions, rising a upsurge of study on solar energy again. A lot of important breakthroughs were made on the survey of solar energy during this phase with the most outstanding ones mentioned below :Taber in Israel put forward the basic theory of selective coat at the first international science conference on solar energy in 1955 and developed the practical black nickel and other selective coats which provided good conditions for the development of the highly effective plate collector. In 1954, Bel’s lab in America created a utility silicon solar powered battery that laid a foundation for the use of photovoltaic power generation on a large scale. Furthermore, there were still some other prominent productions in this phase, for example: the National research center of France invented successfully a solar powered stove with a power of 50kw in the eastern part of Pyrenean in 1952. The world first set of Solar ammonia absorption air-conditioning created in Florida, America in 1960 was heating by flat plate collector with refrigeration power of 5 standardtons. And in 1961, a set of Sterling engine with quartzose windows was come out. During this phase, people reinforced the basic theory of solar energy together with the study of the basic materials and obtained important breakthroughs in techniques such as the solar powered selective coat and the silicon solar powered batteries. The flat plate collector was developed rapidly , it also intent to be more mature gradually in the technique. The study of Solar ammonia absorption air-conditioning had been evolved, which helped people build a passel of utility solar powered houses. People in this period also made a primary research on the difficult sterling engine and the Tower solar thermal technology for power generation.
The Fourth Phase ( from 1965 -1973 )
The study of solar energy was stagnant during this period. These were the main reasons : the technique for the using of solar energy was not mature as it was still in the shaping stage, and it was a large investment with unideal effects which was rather difficult to compete with the routine resources. As a result, it couldn’t get the appreciation and suport from the public, corporation and even the government.
The Fifth Phase ( from 1973 -1980 )
Since the rock oil had played an important role in the global energy resource structure, it became the key factor that controled the economic activities and determined the rise and fall together with its development of the the nation. To protect the interests of their own nation, majority of the oil exporting countries took actions by reducing oil output while increasing its price to sustain the battles of people in the Mid East after the burst of the Mid East War in October 1937, giving a heavy hit in economy on those nations who depended on the Mid East areas to import large quantity of cheap rock oil. Therefore, a exclamation appeared in the west that the global “energy crysis” had just burst out (also called “oil crisis”), from which made people objectively realised that the currently owned energy resource structure need a thorough reformation to be transited to the future energy structure acceleratively. As a result, it made numerous countries, especially highly developed industrial ones, restrengthened their suport for solar energy together with the techno-development of other renewable energy resources. Again, an upsurge on the development and use of solar energy swept all over the world. In 1973, the Americans worked out an govermental plan for generating electricity by solar energy, making the research funds on it increased to a large extent. Besides, a developing bank of solar energy also being established which helped promoting the commercialization of solar powered products. Japan declared the government-made “solar project” in 1974, on which they had spent plentiful manpower, material resources and money, with the following mentioned research and development projects on solar energy included : solar powered houses, solar powered industrial system, Solar thermal power generation, the production system of solar powered batteries, distributed and large-scale photovoltaic power generation system,etc. Our country was also enormously influenced In the early 1970s when the upsurge on the development and use of solar energy appeared. Many technicians with foresight devoted themselves to the career of solar energy one after another, providing proposals actively to the concerned departments of the government, publishing books and newspapers, and introducing the international trends of solar energy use. They spreaded the application of solar energy to kitchen range in the countryside, developed solar powered water heater in cities, and the solar powered batteries for room-usage began to be used on the groud… . The “First National Communication Conference on the Working Experence of Solar Energy Use “was held in Annam, Henan province ,which further promoted the development of the solar career in our country. After this conference, the tasks for studing and spreading of solar energy were brought into the govermental projects, which gained special technical funds and material suport. Some universities and scientific academies set up in succession topic groups and labs on the study of solar energy , some districts even began to raise money to found solar energy academies. There was also an upsurge on the development and use of solar energy in our motherland then and there. The development and use of solar energy during this phase was at its most developed period that didn’t happen ever before with its main features mentioned below: Each country had reinforced their projects on the study of solar energy, furthermore, numerous of them had established solar projects both for Short-term and long-term. The development and use of solar energy had become one of the govermental behaviors which got more and more suport . Some countries in the third world began to participate in the development and use of solar energy, making the international cooperation especially brisk. The research field was continually extended and the study was in-depth day by day, having achieved a passel of biggish breakthroughs such as CPC , vacuum collector tube, amorphous silicon solar cells, hydrogen production from water-ray, solar thermal power generation,etc. Generally speaking, the developing plans made by each country were facing with high requests and previous problems which shown the lack of estimate in the application process and their wishes for the replacement of the mineral resources within a short time so as to achieve making use of the solar energy on a large scale. For example, the United states once planed to build a mini solar powered demonstrative satellitic power station in 1985 and a space solar power station of five million kw in 1995. In fact, however, this project had been adjusted later and the space solar power station didn’t blast off till now. The commercialization of solar powered water heater and solar powered batteries together with other products began to be realised, the solar powered industry was built primarily but with small scale and nonideal economic benefit.
The Sixth Phase ( from 1980 -1992)
The upsurge on the development and use of solar energy swept in the 1970s began to decline in the early 1980s and gradually be at low tide. The research fund on solar energy was decreased largely in many countries in the world (especially in the USA)one after the other. The following main reasons resulted in such a phenomenon : The price of the global rock oil was largely reduced while it kept raising for that of the solar powered products which shown its lack of competition. Besides, there weren’t any other breakthroughs for the solar powered techniques and the aim of enhancing the efficiency while reducing their costs didn’t realize which finally fluctuated the confidence of those who desired to develop and use the solar energy. Moreover, the rapid development of nuclear power would have restrained that of the solar energy to a certain extent. Be affected by the international decline of the solar energy in the 1980s, the study of it in our country also be impaired lot. Some one even thought that the use of solar energe was with high investing risks, bad effects, hard reserving capability and wide occupational areas. They said that it was a kind of future energy resource and claimed we could introduce this technique from foreign countries after they have successfully developed it. Such an opinion could be very harmful though few of us held it, as it would cause some bad influences on the development for the career of solar energy in our country. Although the funds on the development and study of solar energy had been decreased largely, the researches didn’t be ceased during this phase. Cheeringly, many of the studied items got great improvement which made people inspired to look back on their former plans and established aims carefully, adjusted the key point of researches , and struggled for greater study fruits with less devotion.
The Seventh Phase ( from 1992 till now)
The large quantity of burning mineral resources caused the global environmental pollution and damaged the balance of the ecosystem which heavily threatened the survival and development of human beings. The U.N. held a conference on the global environment and its development in Brazil in 1992 under such a condition, series of important files were adopted ,which included bringing the environment together with its development into a united frame and established the mode of sustainable development, such as《Rio de Janeiro Declaration on Environment and Development》,《Agendas of the 21st Century》and《United Nations Framework Convention on Climate Change》,etc. After this conference, each country reinforced the exploration of clean energy technology, leading the work on use of solar energy out of its low tide and being enhanced gradually by uniting the use of solar energy and environmental protection. After the World Conference on Environment and Development, the development of environment gained high appreciation from our national government ,and meanwhile, 10 strategies and measures were put forward which definitely adjusted measures to local conditions for the development and wide use of some clean energy sources such as the solar energy, wind energy, geothermal energy, tide energy, biomass energy, etc. And also worked out the the《China’s Agendas in the 21st Century》which further confirmed the key developing items on solar energy. In 1995, the State Planning Commission together with the National Committee of Science and the State Economic and Trade Comission constituted the《The Developing Programs on New and Renewable Energy Resources》(1996-2010),which definitely indicated the developing purposes together with the tasks and appropriate strategies and measures of the new and renewable energy resources from 1996-2010. The establishment and application of these documents had further played an important role in promoting the career of solar energy in our country. The U.N. delivered《Harare Declaration on Solar Energy and Sustainable Development》in 1996 after the conference on the global fastigium of solar energy held in Zimbabwe,which further indicated the decisive determinations of the U.N. and countries all over the world on the development of solar energy, inspiring all the global human beings started to make use of solar energy widely. They also discussed some important documents in the meeting such as《World Solar 10-year plan of action》(1996- 2005),《International Convention on Solar Energy》and《World Solar Strategic Planning》. After 1992, the global use of solar energy entered a developing era again with the following typical features: The use of solar energy was combined closely with the world sustainable development and environmental protection while the global people came to take actions together to struggle for the realization of the developing strategy of solar energy. The definite aims on the development of solar energy together with the outstanding keystones and reasonable measures were propitious to overcome abuses that were in fits and starts, so as to gaurentee the long-term development of solar career. At the meantime of enhancing the study of solar energy , the economic benefit was gradually promoted by paying attention to turn the scientific and technological achievements into productivity , developing the solar powered industry, speeding up the commercialization course and enlarging fields and scales of solar energy use . The international cooperation on the solar field was unparalleledly brisk with enlarging scope and remarkable effects. We note from the above mentioned retrospection that the development of solar energy was not smooth during this 100 years of the century. Generally speaking, a low tide with a period of about 45 years would be followed after a high tide almost every time. As the diversity in the development on the use of solar energy from coal ,oil and nuclear energy, people got big difference and reiteration on the understanding of it, resulting in a long time on its development . On the one hand, it indicated the big difficulty in the development of solar energy and the realization for the wide use of it within a short time. On the other hand, it revealed that the solar energy was still influenced by the supply of mineral energy resources and the wars,etc. Its development path was twists and turns. In spite of this, the progress achieved on solar technology in the 20th century was generally greater than every era before.
The United States’ plans to transmit solar energy from space to earth
In order to develop renewable energy resources to curb the growing trend of global warming, a new high technology corporation established in the United States was planning to transmit solar energy from the space to the earth.
This company which named Daylight corporation , planned to collect solar energy by taking advantage of the satellite solar batteries which were transmitted to the synchronous orbit on the earth. Then transformed it into RF can to be transmitted into the ground receiving station located in California. Lastly, the RF can was transformed into electric energy to be input the power grid. This company declared that the developing work on this new technology can be accomplished before the beginning of 2016. It was reported that , the Pacific Gas and Electric Company with its headquarters in San Francisco had signed a purchasing agreement which was firm for 15 years with the Daylight Company.
