1. The seventh stage: 1981~1991

The upsurge of solar energy development and utilization that started in the 1970s began to ebb shortly after entering the 1980s, and gradually entered a trough. Many countries have drastically reduced solar energy research funds one after another, of which the United States is the most prominent. The main reasons for this situation are: the world oil prices have fallen sharply, while the prices of solar energy products remain high and lack competitiveness; there is no major breakthrough in solar energy utilization technology, and the goals of improving efficiency and reducing costs have not been achieved. This has shaken the confidence of some countries and people in the development and utilization of solar energy; nuclear power has developed rapidly, which has inhibited the development of solar energy utilization to a certain extent. Although research funding has been drastically reduced, there are still some research projects at this stage that have not been interrupted and good progress has been made. For example, from 1981 to 1991, more than 20 solar thermal power stations with a capacity of 500kw or more were built in the world. Among them, 9 trough solar thermal power stations were built in the California desert from 1985 to 1991, with a total installed capacity of 353.8MW. ; In 1983, the United States built a 1MW photovoltaic power station, followed by a 6.5MW photovoltaic power station in 1986.

2. The eighth stage: 1992 to present

The massive consumption of fossil energy has caused global environmental pollution and ecological damage, posing a serious threat to human survival and development. In this context, the United Nations held the “World Conference on Environment and Development” in Brazil in June 1992. The meeting passed a series of important documents such as the Rio de Janeiro Declaration on Environment and Development, which closely integrated environment and development and established a model for economic and social development on the road of sustainable development. After the conference, countries around the world have strengthened the research and development of clean energy technologies, closely integrating the use of solar energy with environmental protection, so that the development and utilization of solar energy has come out of the trough, and gradually gained attention and strengthened. In 1996, the United Nations held the “World Solar Summit” in Harare, the capital of Zimbabwe. Important documents such as the “World Solar Energy 10-year Action Plan (1996~2005)”, “International Solar Energy Convention”, “World Solar Energy Strategic Plan” and other important documents were discussed at the meeting. After the meeting, the “Harare Solar Energy and Sustainable Development Declaration” was issued. This meeting further demonstrated the firm determination and confidence of the United Nations and other countries in the world to develop the use of solar energy, and called on the world to take joint action to widely develop the use of solar energy. After this conference, the Chinese government attached great importance to the environment and development, and placed great emphasis on the development of new and renewable energy sources such as solar energy. In August 1992, the State Council approved the “Top Ten Countermeasures for China’s Environmental Development”, which clearly proposed to “Develop and promote clean energy such as solar energy, wind energy, geothermal energy, tidal energy, and biomass energy in accordance with local conditions”. In 1995, the State Planning Commission (hereinafter referred to as the “State Planning Commission”), the State Science and Technology Commission, and the State Economic and Trade Commission formulated and issued the “New Energy and Renewable Energy Development Outline (1996~2010)”, and proposed China’s development goals, tasks and corresponding policies and measures for new energy and renewable energy from 1996 to 2010. In August 2000, the State Economic and Trade Commission formulated and issued the “Main Points of the Development Plan for New Energy and Renewable Energy Industries from 2000 to 2015”, which put forward the tasks, goals and related policies, methods and measures for the construction of China’s new energy and renewable energy industries. After 1992, the world’s solar energy utilization has entered a new stage of rapid development, with the following characteristics:

(1) The use of solar energy is closely integrated with the world’s sustainable development and ecological environment protection, and the world is acting together to achieve the world’s solar energy development strategy.

(2) The development goals are clear, the key points are prominent, and the measures are effective. It overcomes the past shortcomings of fluctuating cold and hot, overheating, and enabling the solar energy industry to develop healthily, steadily and sustainably.

(3) While increasing research and development efforts, pay attention to transforming research and development results into products as soon as possible, continue to expand the application field and application scale of solar energy, strive to reduce costs, vigorously improve economic efficiency, actively develop the solar energy industry, and accelerate the process of commercialization.