Various methods of utilizing solar energy
From 1974 to 1997, the cost of silicon semiconductor photovoltaic power generation in developed countries such as the United States and Japan dropped by an order of magnitude: from US$50 per watt to US$5. . Since then, most experts from all over the world believe that there is still a long way to go before solar power plants can be economically competitive with traditional power plants (mainly thermal power plants) - their costs must be reduced by another order of magnitude. At present, there are many projects built in the United States and other countries that use solar pools to generate electricity. On the shore of the Dead Sea, there is an experimental solar pool of 7,000 square meters built in 1979, which provides heat for a 150-kilowatt generator. The United States plans to build 8.3% of its salt lake area (approximately 8,000 square kilometers) into solar pools to provide heat for 600-megawatt generating units. In June this year, experts from the Armenian Institute of Radio Physics announced that they had begun construction of their “first small experimental prototype” industrial solar power station in the country’s mountains. The turbines used in this power station are not new, but turbines that have expired and were removed from helicopters. The installed capacity is only 100 kilowatts, but the power generation cost is only 0.5 cents/kilowatt hour, and the efficiency is as high as 40%-50%. .
Russian scholars have also made remarkable progress in solar pool research. One company combined the solar water jet thrusters and jet-cooled thrusters it developed with the solar pool project, attached ice troughs and other facilities to the solar pool, and designed a new solar pool suitable for farmers. According to this design, a farmer with 6 to 8 people can build a 70-square-meter solar pool to meet the electricity needs of his 100-square-meter house throughout the year. Another research institution proposed the design idea of ??a combined solar pool power station, which uses heat pumps, heat pipes and other technologies to comprehensively utilize solar energy, geothermal energy, and indoor waste heat, greatly reducing the cost of solar pool power generation. Power stations compete and are available all year round, for air conditioning in the summer and heating in the winter.
For countries lacking fresh water resources, the solar pool has another rare benefit: According to expert calculations, a solar pool with an area of ??2,163 square kilometers and a depth of 1.2 meters can be built in a shallow offshore area. The pool can provide heat for a 10-gigawatt power generation unit and produce 2 cubic kilometers of fresh water per year.
In some advanced countries in Europe and the United States, "photoelectric glass curtain wall products" are currently being widely used. This is a method of sealing solar energy conversion silicon wafers in double-layer tempered glass (such as laminated glass) to safely A new type of ecological building material that converts solar energy into electrical energy. The "Photovoltaic Building Plan" in the United States, the "Million Rooftop Photovoltaic Plan" in Europe, the "Asahi Plan" in Japan, and the "Bright Project" that has been carried out in my country will set off an upsurge in the development and application of energy-saving, environmentally friendly and ecological building materials in the construction field, which will greatly Promote the application of solar energy in new building materials products.
In developing countries, countries are also actively developing and utilizing solar energy. For example, in the Philippines, as early as 1999, the government had approved the first solar energy plan. With the assistance of the Australian government's "Overseas Assistance Program", 1,000 solar energy systems were installed in 263 communities across the country. The Philippine government is currently implementing the world's largest solar energy application plan. The entire plan costs US$48 million and is the largest solar energy plan in the world so far. The solar power generation project is divided into two phases. In addition to residential buildings, it also benefits from 25 irrigation systems, 97 water purification and distribution systems, 68 schools and community centers, and 35 clinics.
From this point of view, the solar energy era that all mankind has dreamed of is actually around the corner, including going to space to collect solar energy, transmitting it to the earth, and turning it into electricity to solve the energy problems faced by mankind. crisis. With the advancement of science and technology, this is no longer a dream. The world's first solar power station, built by NASA and the National Department of Energy, will recently be assembled in space and will soon begin supplying power to the ground.
In my country, the utilization of solar energy has always been the hottest topic. After years of development, domestic thermal collectors (including solar water heaters) have become one of the industries with the most extensive application of solar energy and the fastest industrialization. one. In 1998, total sales reached 3.5 billion yuan, and its output ranked first in the world. Our country's solar energy industry has begun operations. The Chinese Academy of Sciences announced the launch of the Western Action Plan, which will invest 250 million yuan in research within two years and establish several demonstration projects such as solar power generation, solar heating, and solar air conditioning.
Currently, Hebei Baoding National High-tech Development Zone is accelerating the construction of my country's largest polycrystalline silicon solar cell production base. The project integrates solar cells, components and application systems. After the completion of the first phase of the project, it can reach an annual output of 3 MW of polycrystalline silicon solar cells. The capabilities have filled many gaps in my country's solar energy development and application, and will greatly promote the production and sales market of low-iron glass for solar cells. However, from an overall analysis, the domestic solar photovoltaic power generation system started late, especially in the development and production of solar cells, which still lags behind the international level. Overall, it is still in the early stage of small output, narrow application range, single product, and backward technology. stage. Rough statistics show that there are currently only 5 (monocrystalline silicon) solar cell production plants in China, with an annual output of about 4.5 megawatts (note: 1 megawatt (MW) is 1000 kilowatts), and the factory facilities are still at the existing level. introduced on the production line. Many foreign companies have set their sights on the development and production of more advanced thin-film crystal solar cells. This new generation of advanced thin-film crystal solar cells has a conversion efficiency as high as 18.3%, which is 3 percentage points higher than the current average conversion efficiency. According to industry insiders, the average conversion efficiency of solar cells in my country is not high. The main reason is that the degree of localization of special materials is low. For example, packaging glass is completely dependent on imports. The market for high-transmittance substrate glass with low iron content still cannot meet the demand. Scientific research The results have not been quickly and completely transformed into industrial advantages.
At present, the State Planning Commission and the State Science and Technology Commission have given strong support to the development of solar energy technology and its applications, and many domestic companies have been involved. BNBM Group is one of the first units to organize experts to investigate the domestic and international solar photovoltaic power generation industry. In 1998, it was the first in China to introduce a 76-kilowatt internationally advanced rooftop solar power generation system. It has been operating stably and with good results to this day. The average daily power generation of this system is more than 12 kilowatt hours, which can meet the electricity requirements of a well-off household. The group has also established a joint venture with the Swiss company ATLANTIS, Beijing-ATLANTIS Solar Technology Co., Ltd., to produce two series of solar photovoltaic power generation modules and roof power generation modules, and multiple varieties of photovoltaic power generation products, and integrate this world-leading New technologies for solar energy utilization were introduced into China.
Hebei Zhenhai Aluminum Group Co., Ltd. is the exclusive general agent of German Piikington Solar Energy International Co., Ltd. in China. It has now invested in the production of world-leading solar cell glass packaging equipment and supporting materials, such as Germany Quality wet glass lamination equipment, wet grouts (encapsulating media) and more from Kemet Chemicals. The base of Zhenhai Group was the first in my country to install a photovoltaic glass curtain wall demonstration building with an area of ??more than 100 square meters in November 1999. It has been completed and put into use. Its operation and use effects are good, and it has become a major domestic landscape and solar photovoltaic power generation A model of engineering.
Solar collector tube is a patented technology of Tsinghua University. It has been industrialized by Tsinghua Sunshine Company. Its annual output is currently the first in the world, and its product performance is world-leading. Tsinghua Sunshine Company’s Shaile brand solar collector tubes and collector devices, it took six or seven years to complete small-scale testing, pilot testing and large-scale production. At present, it has built the world's largest collector tube production plant, with an annual production capacity of 5 million units. The world's highest heat collection efficiency The highest all-glass vacuum collector tube, the business volume of this project is expected to reach 1 billion yuan in another three years.
In the 2008 Olympic Games, Beijing will become my country's largest display window for solar energy applications. The "New Olympics" will fully embody the new concept of "environmental protection Olympics, energy-saving Olympics". It is planned that 80% to 80% of the surrounding areas around the Olympic venues will be 90% of the street lights will use solar photovoltaic power generation technology; all-glass vacuum solar heat collection technology will be used to supply 90% of the hot water for bathing in the Olympic Games. During the entire Olympic Games, we will see the application of solar street lights, solar phones, solar mobile phones, solar flush toilets, etc. with a series of solar technology applications. Our life will be full of sunshine!