The principle and advantage of photovoltaic power generation

Solar photovoltaic power generation principle:

Photovoltaic power generation is a technology that converts light energy directly into electrical energy by using the photovoltaic effect of semiconductor interface. The main core components of photovoltaic power generation are solar cells, and other components include batteries, controllers, and so on. Solar cells store sunlight, and then through a series of technical operations to convert its solar energy into electricity, the advantage of this technology is that as long as there is light, solar cells can collect and reserve sunlight.

The process of converting solar energy into electricity mainly includes three steps:

1.After the solar cell absorbs a photon of a certain energy, an electron hole pair is generated in the semiconductor, which is called "photogenerated carrier", and the electrical polarity of the two is opposite, the electron is negatively charged, and the hole is positively charged.
2.Photogenerated carriers with opposite electrical polarity are separated by the electrostatic field generated by the semiconductor PN junction.
3.Grid connected pv system, that is, connected to the national grid. China's photovoltaic grid-connected power generation has been very mature, to encourage the conditions of regional industry and commerce and household, public buildings and other construction of photovoltaic power generation facilities, power generation for their own use at the same time can also enjoy the sale of electricity income.

Solar photovoltaic power generation systems are mainly used in the following three major aspects:

1.To provide power for non-electric occasions, mainly for the majority of non-electric areas to provide electricity for the living production of residents, microwave relay stations and mobile phone base stations to provide power.
2.Solar daily electronic products, such as all kinds of solar chargers, solar street lights and solar lawn lights.
3.Grid-connected power generation, that is, connected to the national grid. China's photovoltaic grid-connected power generation has been very mature, to encourage the conditions of regional industry and commerce and household, public buildings and other construction of photovoltaic power generation facilities, power generation for their own use at the same time can also enjoy the sale of electricity income.
Advantages of solar power:

1.Economic advantage:

Solar energy is inexhaustible, and solar energy can generate electricity as long as there is light, which is very convenient; At the current level of technological development, the use of some solar energy has become economical.

With the development of science and technology and the breakthrough of human development and utilization of solar energy technology, the economy of solar energy utilization will be more obvious. If the 20th century was the century of oil, then the 21st century is the century of renewable energy (photovoltaic century).
From the perspective of the construction cost of solar photovoltaic power station, with the large-scale application and promotion of solar photovoltaic power generation, especially the maturity of the upstream crystalline silicon industry and photovoltaic power generation technology, the composite development and utilization of building roofs, external walls and other platforms, the construction cost of solar photovoltaic power generation per kilowatt is getting lower and lower, compared with other renewable energy sources has the same economic advantages. And with the implementation of the national parity policy, its popularity will be more and more widespread.
2.Solar energy is an inexhaustible renewable energy source:

According to calculations, the total amount of solar energy reaching the earth's surface in a year is equivalent to about 1.892x10^24 tons of standard coal, which is 10,000 times the proven reserves of the world's main energy sources. The life of the sun is at least 4 billion years, relative to human history, solar energy can supply the earth's time can be said to be unlimited, which determines that the development and use of solar energy will be the most effective way to solve the shortage and exhaustion of conventional energy.

3.No pollution to the environment:

As a kind of ideal clean energy, solar energy is being paid more and more attention by all countries in the world. From the current carbon emission rate of various power generation methods (g/kW·h), do not calculate its upstream links, coal power generation is 275g/kW·h, oil power generation is 204g/kW·h, natural gas power generation is 181g/kW·h, wind power is 20g/kW·h, and solar photovoltaic power generation is close to zero emissions. And, in the power generation process, there is no waste residue, waste, waste water, exhaust gas discharge, no noise, no harmful substances to the human body, will not pollute the environment.

4.The energy conversion process is minimal:

From the point of view of energy conversion, solar photovoltaic power generation is the direct conversion of solar radiant energy into electrical energy, in all renewable energy utilization, solar photovoltaic power generation conversion link is the least, the most direct use. Generally speaking, in the energy flow of the entire ecological environment, with the increase of the conversion link and the extension of the conversion chain, the energy loss will be geometrically increased, and at the same time greatly increase the construction, operating costs and instability of the entire system. At present, the practical level of photoelectric conversion efficiency of crystalline silicon solar cells is 15%-20%, and the highest level in the laboratory has reached 35%.