Principles and advantages of photovoltaic energy
Principles and advantages of photovoltaic energy:
Principle of solar photovoltaic energy production
The photovoltaic effect occurs in both liquid and solid substances, but only solids (esp semiconductor PN junction devices) have higher photoelectric conversion efficiency under sunlight. The crystalline silicon solar cells are made using the principle of the photovoltaic effect, which can directly convert the light energy of the sun into electricity. The energy converter of solar photovoltaic power generation is the solar cell, also known as photovoltaic cell, which is the basis and core of the solar photovoltaic power generation system.
Principles and advantages of photovoltaic energy
The process of converting solar energy into electricity mainly includes 3 stages:
(1) After the solar cell absorbs photons of a certain energy, electron-hole pairs are created in the semiconductor, which are called "photogenerated carriers". positively charged.
(2) Photogenerated carriers with opposite polarities are separated by the electrostatic field created by the semiconductor PN junction.
(3) The photogenerated electrons and current-carrying holes are collected by the positive and negative electrodes of the solar cell, respectively, and generate current in the external circuit, thus receiving electrical energy.
In solar power generation system, the overall performance η of the system is determined by the photoelectric conversion efficiency of the solar cell module, the controller efficiency, the battery efficiency, the inverter efficiency and the load efficiency. At present, the photoelectric conversion efficiency of solar cells is only about 17%.
Therefore, improving the photoelectric conversion efficiency of solar cell modules and reducing the unit power cost of solar PV power generation systems is the focus and difficulty of solar PV power generation industrialization. Since the advent of solar cells, crystalline silicon has maintained its dominance as the primary material.
At present, research on the conversion efficiency of silicon solar cells is mainly focused on increasing the energy absorption surface (such as using double-sided cells to reduce reflection), using capture technology and passivation technology to improve the conversion efficiency of silicon solar cells . and ultra fine cells etc. crumple.
Advantages of solar energy production:
(1) Photovoltaic energy production has economic advantages
(2) Solar energy is an inexhaustible renewable energy
(3) No environmental pollution
(4) The energy conversion coupling is the minimum
(5) The most economical and environmentally friendly
(6) Free to use and no transfer required
Currently, solar photovoltaic power generation systems are mainly used in the following three main aspects.
(1) Provide power for non-electrical occasions, mainly provide electricity for the living and production of residents in non-electrical areas, and provide power for microwave relay stations and mobile phone base stations.
(2) Solar daily electronic products, such as various solar chargers, solar street lights and solar lawn lights, etc.
(3) Grid-connected electricity generation, i.e. access to the national grid. My country's solar power generation is very mature. Since 2013, the state has issued a series of policies to promote the production of photovoltaic energy to encourage the construction of photovoltaic power generation facilities in industrial and commercial, residential and public buildings in areas where conditions permit.
