Solar cells with an area of 100㎝2 generate about 1 watt of electricity under strong sunlight. We often say that 1 kwh is 1 kwh, that is, a battery like 1 kwh can only produce 1 kwh after working 1 hour.
General situation of solar cell development
Solar photovoltaic power generation can be regarded as the most wonderful, long-lived and reliable power generation technology so far. Compared with solar power generation, it involves semiconductor devices, no moving parts and no flowing working medium. Therefore, the problems of mechanical maintenance and working medium corrosion are avoided, and it is a renewable energy source and a reliable energy source for sustainable development.
The development of silicon solar cells began in 1954, and was successfully trial-produced by Bell Institute in the United States. The following year, it was used as the power supply for telecommunication equipment, and was first applied to Pioneer 1 satellite in the United States in 1958. The development of the universe has greatly promoted the development of solar cells. At the same time, the research of ground solar cells is also going on, especially the energy crisis of 1973, which greatly accelerates the development of ground solar cells. Many countries have invested considerable funds in the development and utilization of solar cells and the research of solar power generation. So far, most of the thousands of planes flying in space are equipped with solar cell systems. The launch of the first artificial satellite is the starting point for the development and utilization of photovoltaic technology. After nearly 50 years of development, a new photovoltaic science and photovoltaic engineering has been formed. Whether it is used in aerospace or as a ground power generation system, photovoltaic technology is a leader in new energy sources in terms of development speed, technical maturity and application field.
As a potential renewable energy source, solar cells are gradually popularized on the ground. The cost and selling price of solar cells are also decreasing year by year, and the output of solar cells has been increasing at a growth rate of 10-25% for many years. 1990, the output of solar modules in the world was 70MW, and that in China was 1.2MW, which was mainly used in remote areas with good sunshine. By 200 1, the output of solar cells in the world has reached 350MW, the actual output of solar cells in China has reached 4.5MW, and the cumulative installed capacity has exceeded 20MW. China is a developing country with a vast territory and many remote provinces and underdeveloped areas. According to statistics, there are currently 7 million households (population 28 million) without electricity in China, and 60% of counties with electricity are seriously short of electricity. In these areas, it is impossible to solve the problem of electricity consumption in a short time with conventional electricity, and photovoltaic power generation is an ideal way to solve the problem of farmers and herdsmen's dispersion, with great market potential.
Photovoltaic power generation has many advantages, such as safety, reliability, no noise, no pollution, energy available everywhere, no geographical restrictions, no fuel consumption, no mechanical rotating parts, low failure rate, simple maintenance, unattended, short construction period, arbitrary scale, no need to erect transmission lines, and convenient combination with buildings. These advantages are beyond the reach of other power generation methods.
At present, there are three kinds of solar cells widely used in the world: monocrystalline silicon solar cells, polycrystalline silicon solar cells and amorphous silicon solar cells, each of which accounts for about 1/3 of the market. At present, there are seven solar cell production lines in China, mainly producing monocrystalline silicon and amorphous silicon solar cells, and a small amount of polycrystalline silicon solar cells. The efficiency of producing monocrystalline silicon solar cells in China is 12- 13%, polycrystalline silicon solar cells are 10%, and amorphous silicon solar cells are 5-6%. Crystalline silicon solar cells are developing towards high efficiency, thinness and large area. 1995, the reference price of crystalline silicon solar cell module in China is 45 yuan/watt, and that of amorphous silicon solar cell module is 25 yuan/watt, which is still several times that of conventional energy, but it has produced good economic benefits in areas without electricity and places with inconvenient cables.