Solar photovoltaic power generation system is a new type of power generation system, which uses the photovoltaic effect of semiconductor materials of solar cells to directly convert solar radiation energy into electric energy. There are two modes of independent operation and grid-connected operation. Independent photovoltaic power generation system needs storage battery as energy storage device, which is mainly used in remote areas without power grid and scattered population areas, and the whole system cost is very high; In areas with public power grids, grid-connected photovoltaic power generation system can not only greatly reduce the cost, but also have higher power generation efficiency and better environmental protection performance.

The history of solar cell power generation

Since the first practical photovoltaic cell of 1954 came out, solar photovoltaic power generation has made great progress. But it is much slower than the development of computer and optical fiber communication. The reason may be that people's pursuit of information is particularly strong, and conventional energy can also meet human demand for energy. The oil crisis of 1973 and the environmental pollution in 1990s greatly promoted the development of solar photovoltaic power generation. Its development process is briefly described as follows:

1839, French scientist becquerel discovered the photovoltaic effect, that is, the photoelectric effect.

1876, Adams discovered the solid-state photovoltaic effect on metal and selenium sheets.

1883 made the first "selenium photocell" as a sensitive device.

Schottky put forward the "photovoltaic effect" theory of Cu2O barrier in 1930. In the same year, Langer first proposed to manufacture a "solar cell" with "photovoltaic effect" to convert solar energy into electric energy.

193 1 year, Bruno dipped the copper compound and silver selenium electrode into the electrolyte and started the motor in the sun.

1932 Audubot and Stora made the first "cadmium sulfide" solar cell.

194 1 year, Orr discovered the photovoltaic effect on silicon.

1954, Chapin and Pirson made a practical single crystal solar cell in Bell Laboratories for the first time, with an efficiency of 6%. In the same year, Vekker first discovered that gallium arsenide has photovoltaic effect, and deposited cadmium sulfide thin film on glass to make the first thin film solar cell.

In 1955, Ginny and Rofesky optimized the photoelectric conversion efficiency of materials. In the same year, the first photoelectric beacon light came out. American RCA studies gallium arsenide solar cells.

The efficiency of 1957 silicon solar cell reaches 8%.

1958, solar cells were first used in space, equipped with the power supply of American pioneer 1 satellite.

1959, the first polysilicon solar cell came out with an efficiency of 5%.

1960 silicon solar cells are connected to the grid for the first time.

The photoelectric conversion efficiency of 1962 GaAs solar cells reaches 13%.

The efficiency of 1969 thin-film cadmium sulfide solar cell reaches 8%.

1972, Rogowski developed a purple light battery with an efficiency of 16%.

1972 American space company's back field battery came out.

1973 GaAs solar cell efficiency reaches 15%.

1974, COMSAT Institute proposed a non-reflective textured battery, and the efficiency of silicon solar cells reached 18%.

1975 Amorphous silicon solar cells came out. In the same year, the efficiency of silicon-containing batteries reached 6%~%.

The efficiency of 1976 polysilicon solar cell reaches 10%.

1978, the United States built 100kWp solar ground photovoltaic power station.

1980, the efficiency of monocrystalline silicon solar cell, gallium arsenide cell, polycrystalline silicon cell and cadmium sulfide cell reached 20%, 22.5%, 14.5% and 9. 15% respectively.

1983, the United States built 1MWp photovoltaic power station; The efficiency of metallurgical silicon (epitaxial) battery reaches 1 1.8%.

1986 a 6.5 MW photovoltaic power station was built in the United States.

1990, Germany put forward the "photovoltaic roof plan 2000", and every family installed 3~5kWp photovoltaic cells on the roof.

1995 high-efficiency concentrating GaAs solar cells have an efficiency of 32%.

1997, the United States put forward President Clinton's Million Solar Roof Plan. Twenty10 years ago, there were/kloc-0,000,000 households, each with 3~5kWp installed. Photovoltaic cells. When there is the sun, the photovoltaic roof supplies power to the power grid, and the electric meter reverses; When there is no sun, the power grid supplies electricity to the home, and the electricity meter is turning. Families only need to pay the "net electricity bill".

1997, Japan's "New Sunshine Plan" proposed to produce 4.3 billion Wp photovoltaic cells by 20 10.

1997 EU plans to produce 3.7 billion Wp photovoltaic cells by 20 10.

1998 monocrystalline silicon photovoltaic cell efficiency reaches 25%. The Dutch government put forward the "Dutch Million Solar Photovoltaic Roof", which will be completed in 2020.

Development of photovoltaic power generation industry in China

China is rich in solar energy resources, with theoretical reserves of 65.438+0.7 trillion tons of standard coal per year. The potential for the development and utilization of solar energy resources is very broad. China's photovoltaic power generation industry started in the 1970s and entered a period of stable development in the mid-1990s. The output of solar cells and modules has increased steadily year by year. After more than 30 years of hard work, it has ushered in a new stage of rapid development. Driven by national projects such as "Bright Project" and "Sending Electricity to the Countryside" and the world photovoltaic market, China's photovoltaic power generation industry has developed rapidly.

In 2007, the output of photovoltaic cells in China surpassed German and Japanese for the first time, ranking first in the world. In 2008, the output continued to increase, reaching 2 million kilowatts. In recent five years, the annual growth rate of photovoltaic cell production in China is 1-3 times, and the proportion of photovoltaic cell production in global production has also increased from 1.07% in 2002 to nearly 15% in 2008. The efficiency of commercial crystalline silicon solar cells has also increased from 13%- 14% three years ago to 16%- 17%.

The financial crisis triggered by the subprime mortgage problem in the United States spread rapidly from Wall Street to the whole world, leading to the closure of some financial institutions, the continued downturn in the securities market and the sharp drop in oil prices. China's photovoltaic power generation industry has developed rapidly in recent years, and it has become the world's Sun Valley, which is valued by the government, with an active stock market, favored by venture capitalists and crowded with people from all walks of life. Because of its equipment, raw materials and market, it has great dependence on international markets such as the United States, Europe and Japan. With the financial crisis, especially the sharp drop in international oil prices, it has a great impact on the investment funds and export orders of China's photovoltaic power generation industry, but the huge impact of the financial crisis on the photovoltaic industry will be digested at some time in the future. In the long run, the policy impetus of the world photovoltaic market still exists, and the market growth of the photovoltaic industry is still strong.

Note: For more information, please refer to Photoelectric News Network, which has a special solar photovoltaic channel.