According to records, human beings have used solar energy for more than 3000 years. The use of solar energy as an energy source and power has only a history of more than 300 years. It is a matter of recent years that solar energy is really regarded as "the supplementary energy urgently needed in the near future" and "the foundation of future energy structure". Since 1970s, solar energy technology has advanced by leaps and bounds, and solar energy utilization has changed with each passing day. The history of modern solar energy utilization can be counted from 16 15 when French engineer Solomon de Cox invented the world's first solar engine. The invention is a machine that uses solar energy to heat air to expand it to do work and pump water. During the period of 16 15 ~ 1900, many solar power generation devices and some other solar devices were developed in the world. Almost all of these power plants collect sunlight by concentrating light, and the engine power is not large. The working medium is mainly water vapor, which is expensive and of little practical value. Most of them are developed and manufactured by solar enthusiasts themselves. During the 20th century 100, the development history of solar energy technology can be roughly divided into seven stages. In the fifth stage (1973~ 1980), because oil plays a leading role in the world energy structure, oil has become a key factor affecting the economy and determining the survival, development and decline of a country. 1When the Middle East War broke out in June, 1973, the Organization of Petroleum Exporting Countries took measures such as reducing production and raising prices to support the people in the Middle East. As a result, those countries that rely on importing cheap oil from the Middle East have suffered a heavy economic blow. As a result, some people in the west exclaimed that there was an "energy crisis" in the world (some people called it an "oil crisis"). This "crisis" objectively makes people realize that we must completely change the existing energy structure and accelerate the transition to the future energy structure. Therefore, many countries, especially industrialized countries, have renewed their support for the development of solar energy and other renewable energy technologies, and the upsurge of developing and utilizing solar energy has once again arisen in the world. From 65438 to 0973, the United States made a government-level solar power generation plan, and the funds for solar energy research increased substantially, and a solar energy development bank was established to promote the commercialization of solar energy products. 1974, Japan announced the "sunshine plan" formulated by the government, in which solar research and development projects include: solar houses, industrial solar systems, solar thermal power generation, solar cell production systems, decentralized and large-scale photovoltaic power generation systems, etc. In order to implement this plan, the Japanese government has invested a lot of manpower, material resources and financial resources.

In the early 1970s, the upsurge of developing and utilizing solar energy in the world also had a great influence on China. Some far-sighted scientific and technological personnel have devoted themselves to the solar energy industry, actively made suggestions to relevant government departments, published books and magazines, and introduced the international solar energy utilization trends; Popularize the application of solar cookers in rural areas, develop solar water heaters in cities, and begin to use solar cells in space on the ground. 1975, "the first national solar energy utilization experience exchange conference" was held in Anyang, Henan province, which further promoted the development of solar energy in China. After this meeting, the research and promotion of solar energy was included in the plan of China Municipal Government and received special funds and material support. Some universities and research institutes have successively set up solar energy research groups and laboratories, and some places have also begun to set up solar energy research institutes. At that time, there was an upsurge in the development and utilization of solar energy in China. During this period, the development and utilization of solar energy is in an unprecedented period of great development, with the following characteristics:

Countries have strengthened the planning of solar energy research, and many countries have made short-term and long-term sunshine plans. The development and utilization of solar energy has become a government act, and the support has been greatly strengthened. International cooperation is very active, and some third world countries have begun to actively participate in the development and utilization of solar energy.

The research field has been continuously expanded and the research work has been deepened, and a number of important achievements have been made, such as CPC, vacuum collector tubes, amorphous silicon solar cells, hydrogen production by photolysis of water, solar thermal power generation and so on.

The solar energy development plans formulated by various countries generally have the problems of demanding too much and being too urgent, and the difficulties in the implementation process are underestimated. It is hoped to replace mineral energy in a short time and realize the large-scale utilization of solar energy. For example, the United States had planned to build a small solar demonstration satellite power station in 1985 and a 5 million kilowatt space solar power station in 1995. In fact, this plan was later adjusted, and the space solar power station has not yet been launched.

Solar water heaters, solar cells and other products began to be commercialized, and the solar energy industry was initially established, but the scale was small and the economic benefits were not ideal. This is mainly subject to the application of technology and the level of scientific research. In the seventh stage (1992 ~ present), due to the massive burning of mineral energy, global environmental pollution and ecological destruction have been caused, posing a threat to human survival and development. Against this background, the United Nations held the World Conference on Environment and Development in Brazil in 1992, which adopted a series of important documents, such as Rio de Janeiro Declaration on Environment and Development, 2/kloc-0 Agenda for the Century, and the United Nations Framework Convention on Climate Change, which brought environment and development into a unified framework and established a model of sustainable development. After this meeting, countries all over the world strengthened the development of clean energy technology, and combined the utilization of solar energy with environmental protection, so that the utilization of solar energy went out of the trough and was gradually strengthened. After the World Conference on Environment and Development, the China Municipal Government attached great importance to the environment and development, put forward 10 countermeasures, made it clear that it was necessary to "develop and popularize clean energy such as solar energy, wind energy, geothermal energy, tidal energy and biomass energy according to local conditions", and formulated the China 2 1 Century Agenda, which further clarified the key development projects of solar energy.

1995 In 1995, the State Planning Commission, the State Science and Technology Commission and the State Economic and Trade Commission formulated the Outline for the Development of New and Renewable Energy, which was formulated in (1996 ~ 20 10) and clearly stated that 196 ~ 20 10. The formulation and implementation of these documents have played an important role in further promoting the development of China's solar energy industry. 1996, the United Nations held the World Solar Summit in Zimbabwe. After the meeting, the Harare Declaration on Solar Energy and Sustainable Development was issued. Important documents such as 10 (1996 ~ 2005) World Solar Action Plan, International Solar Congress and World Solar Strategic Plan were discussed. This meeting further demonstrated the firm determination of the United Nations and other countries in the world to develop solar energy, and called for global joint action to make extensive use of solar energy.

After 1992, the world's solar energy utilization has entered a development period, which is characterized by: the solar energy utilization is closely combined with the world's sustainable development and environmental protection, and the world acts together to realize the world's solar energy development strategy; The development goal of solar energy is clear, the key points are prominent, and the measures are effective, which is conducive to overcoming the disadvantages of cold and hot and overheating in the past and ensuring the long-term development of solar energy; While increasing the research and development of solar energy, we should pay attention to the transformation of scientific and technological achievements into productive forces, develop the solar energy industry, speed up the commercialization process, expand the field and scale of solar energy utilization, and gradually improve economic benefits; International cooperation in the field of solar energy is unprecedentedly active, with expanded scale and obvious effects. From the above review, we can see that the development path of solar energy is not smooth in the 100 year of this century. Generally, there will be a low tide after every high tide, and the low tide time is about 45 years. The development process of solar energy utilization is completely different from that of coal, oil and nuclear energy, and people have different understandings of it, which is repeated many times and takes a long time to develop. On the one hand, it shows that it is difficult to develop and realize large-scale utilization of solar energy in a short time; On the other hand, it also shows that the utilization of solar energy is also affected by mineral energy supply, politics and war, and the development road is tortuous. Nevertheless, on the whole, the progress of solar technology in the 20th century is still faster than any previous century. Aidi solar energy is now an indispensable part of people's lives. Photovoltaic panels around the world are connected to the grid, and the problem of difficult energy storage has been improved.

Developing economic problems

First of all, more and more countries in the world realize that a sustainable society should meet the needs of society without endangering the future of future generations. Therefore, replacing fossil energy with clean energy as much as possible is the principle that energy construction should follow. With the change of energy form, the storage of conventional energy is decreasing day by day, and its price is bound to rise, so it is necessary to increase investment to control environmental pollution.

Second, China is the largest producer and consumer of coal in the world, and coal accounts for about 76% of the consumption structure of commodity energy, which has become the main source of air pollution in China. Vigorously developing the utilization technology of new energy and renewable energy will become an important measure to reduce environmental pollution. The energy problem is worldwide, and the period of transition to new energy will come sooner or later. In the long run, the wide application of solar energy utilization technology and devices will inevitably restrict the rise of mineral energy prices.