The world's first panda-shaped photovoltaic power station was built in the suburb of Datong, Shanxi, and was officially connected to the grid for power generation recently. The power station is composed of black and white. If viewed from a height, the black parts such as panda's claws and ears are made of monocrystalline silicon solar cells; The white part consists of thin-film solar cells. ?
Aerial view of Datong Panda Power Station (picture from network)?
It is reported that the power station can provide 3.2 billion kWh of green electricity within 25 years after it is fully put into use, which is equivalent to saving 6.5438+0.056 million tons of coal and reducing 2.7 million tons of carbon dioxide emissions. ?
How does this "the cutest power station in the world" which is called by netizens work? This mainly depends on solar photovoltaic power generation. ?
What is the principle of solar photovoltaic power generation?
In the context of the continuous shortage of silicon raw materials in the international market, thin-film solar cells have become a new trend and hot spot in the development of the international photovoltaic market. ?
When the sun shines on some special materials, it will cause the electrons in the materials to move and form a potential difference. Solar photovoltaic power generation is based on this principle, using solar cells to directly convert solar energy into electric energy. ?
"National Treasure" Power Station (picture from Xinhuanet)?
Solar radiation energy is directly converted into electric energy by photovoltaic effect, that is, when light strikes the surface of solar cells, some photons are absorbed by solar materials, and photons excite electrons to jump to the conduction band and become free electrons. Therefore, a potential difference is generated between different parts of an uneven semiconductor or a combination of a semiconductor and a metal. With voltage, it is like building a dam. If the two are connected, an electric current will be formed. The process of solar photovoltaic power generation is actually a process in which photons (light waves) are converted into electrons and light energy is converted into electric energy. ?
Schematic diagram of solar photovoltaic power generation (picture from network)?
Basic structure of photovoltaic cells?
Light irradiation generates photovoltaic current and voltage on photovoltaic cells, thus obtaining electric energy. This conversion process first requires the material to absorb light, so that electrons can get higher energy, and then the electrons with higher energy move from the battery to the external circuit, releasing these extra energy, and then return to the solar cell. ?
The basic working process of solar cells: generating photogenerated carriers-collecting photogenerated carriers to generate current-generating a larger photogenerated voltage-distributing the generated electric energy to loads and parasitic resistors. ?
Basic structure of solar cells (picture from network)?
What types of photovoltaic cells are there?
Photovoltaic cells are divided into crystalline silicon cells and thin film cells. Crystalline silicon solar cells include monocrystalline silicon solar cells, polycrystalline silicon solar cells and amorphous silicon solar cells. ?
Among them, monocrystalline silicon solar cell is the fastest growing solar cell at present, and its structure and production technology have been finalized, and its products have been widely used in space and on the ground. High purity monocrystalline silicon rod is the raw material of monocrystalline silicon solar cell, and the purity of silicon is required to reach 99.999%. In order to reduce the production cost, all solar cells used on the ground now use solar-grade monocrystalline silicon rods, and the material performance index is relaxed. Some can also make use of the head and tail materials and waste monocrystalline silicon materials processed by semiconductor devices to make monocrystalline silicon rods special for solar cells after redrawing. ?
The black part of Panda Power Station is composed of monocrystalline silicon solar cells (picture from network)?
As the name implies, a thin-film battery is composed of a thin film. At present, there are three kinds of thin-film solar cells that can be industrially produced on a large scale: silicon-based thin-film solar cells, copper indium gallium selenide thin-film solar cells (CIGS) and cadmium telluride thin-film solar cells (CdTe). ?
Silicon-based thin film solar cells (picture from the network)?
Other uses of photovoltaic power generation?
In addition to photovoltaic power plants, there are many application examples of photovoltaic power generation, from solar chargers, solar street lamps and solar navigation lights to solar cars, satellites, lunar rovers, solar airplanes and photovoltaic building integration. ?
Satellite's solar charging board (picture from the network)?
China is currently one of the countries with the largest export share of solar photovoltaic modules in the world. At present, the solar power generation industry in China is stepping into a healthy development track of specialization, scale and internationalization. ?
The picture comes from the internet?