Solar photovoltaic power generation is based on the principle of photovoltaic effect, using solar cells to directly convert sunlight energy into electrical energy. Regardless of whether it is used independently or connected to the grid, the solar photovoltaic power generation system is mainly composed of three parts: solar panels (components), controllers and inverters. They are mainly composed of electronic components, but do not involve mechanical parts.
Therefore, solar photovoltaic power generation equipment is extremely refined, reliable, stable, long-life, and easy to install and maintain. Theoretically speaking, solar photovoltaic power generation technology can be used in any occasion that needs power, ranging from spacecraft to household power, large megawatt power stations, and small toys. Photovoltaic power can be used everywhere.
1. Classification of solar photovoltaic power generation
1.1 Power generation mode
Solar photovoltaic power generation is divided into solar photothermal power generation and solar photovoltaic power generation. Regardless of production and sales, development speed and development prospects, solar thermal power generation cannot keep up with solar photovoltaic power generation. Perhaps due to the widespread popularity of solar photovoltaic power generation, there is less exposure to solar thermal power generation. Generally speaking, solar photovoltaic power generation in the folk often refers to solar photovoltaic power generation, or photoelectricity for short.
1.2 Delivery method
Solar photovoltaic power generation is divided into independent solar photovoltaic power generation, grid-connected solar photovoltaic power generation, and distributed photovoltaic power generation.
1.3 Independent photovoltaic power generation
Independent photovoltaic power generation system is also called off-grid photovoltaic power generation system. It is mainly composed of solar cell components, controllers, and batteries. To supply power to AC loads, an AC inverter is also required.
1.4 Grid-connected photovoltaic power generation
The grid-connected photovoltaic power generation system is that the direct current generated by solar modules is converted into alternating current that meets the requirements of the mains power grid through a grid-connected inverter and then directly connected to the public power grid. The grid-connected photovoltaic power generation system has a centralized large-scale grid-connected photovoltaic power station, which is generally a national-level power station. The main feature is that the generated energy is directly transmitted to the grid, and the grid is uniformly deployed to supply power to users. However, this kind of power station has a large investment, a long construction period, and a large area, making it relatively difficult to develop. Distributed small-scale grid-connected photovoltaic systems, especially building-integrated photovoltaic power generation systems, are the mainstream of grid-connected photovoltaic power generation due to their advantages such as small investment, fast construction, small footprint, and strong policy support.
1.5 Distributed photovoltaic power generation
Distributed photovoltaic power generation system, also known as distributed power generation or distributed energy supply, refers to the configuration of smaller photovoltaic power generation and power supply systems at the user site or near the power consumption site to meet the needs of specific users and support the economy of the existing distribution network. operation, or both.
The basic equipment of the distributed photovoltaic power generation system includes photovoltaic cell components, photovoltaic array brackets, DC combiner boxes, DC power distribution cabinets, grid-connected inverters, AC power distribution cabinets and other equipment, as well as power supply system monitoring devices and environmental monitoring device. Its operation mode is that under the condition of solar radiation, the solar cell module array of the solar photovoltaic power generation system converts the solar energy into the output power, and sends it to the DC power distribution cabinet through the DC combiner box, and is converted into AC power by the grid-connected inverter. The building's own load, excess or insufficient electricity is regulated by connecting to the grid.
2. Theory of solar photovoltaic power generation
Solar photovoltaic power generation is based on the principle of photovoltaic effect, using solar cells to directly convert sunlight energy into electrical energy. Regardless of whether it is used independently or connected to the grid, the solar photovoltaic power generation system is mainly composed of three parts: solar panels (components), controllers and inverters. They are mainly composed of electronic components and do not involve mechanical parts. Therefore, solar photovoltaic power generation equipment Extremely refined, reliable, stable, long life, easy to install and maintain. Theoretically speaking, solar photovoltaic power generation technology can be used in any occasion that needs power, ranging from spacecraft, down to household power, large megawatt power stations, small toys, photovoltaic power is everywhere. The efficiency of domestic crystalline silicon cells is about 10 to 13%, and the efficiency of similar foreign products is about 12 to 14%. A solar panel consisting of one or more solar cells is called a photovoltaic module.
3. Composition of solar photovoltaic power generation
The solar photovoltaic power generation system consists of solar battery packs, solar controllers, and batteries (groups). If the output power is AC 220V or 110V, an inverter is also required. The functions of each part are:
3.1 Solar panel: The solar panel is the core part of the solar power generation system, and it is also the most valuable part of the solar power generation system. Its function is to convert the sun's radiation ability into electrical energy, or store it in the battery, or promote work load.
3.2 Solar controller: The function of the solar controller is to control the working state of the whole system, and to protect the battery from over-charging and over-discharging. In places with large temperature differences, qualified controllers should also have the function of temperature compensation. Other additional functions such as light control switch and time control switch should be optional options of the controller;
3.3 Batteries: generally lead-acid batteries, nickel metal hydride batteries, nickel cadmium batteries or lithium batteries can also be used in small and micro systems. Its function is to store the electric energy from solar panels when there is light, and release it when needed.
3.4 Inverter: The direct output of solar energy is generally 12VDC, 24VDC, 48VDC. In order to provide power to 220VAC electrical appliances, it is necessary to convert the DC power generated by the solar power generation system into AC power, so a DC-AC inverter is required.
4. Application fields of solar photovoltaic power generation
4.1 Transportation fields such as navigation lights, traffic/railway signal lights, traffic warning/sign lights, Yuxiang street lights, high-altitude obstruction lights, highway/railway wireless telephone booths, unattended road shift power supply, etc.
4.2 Communication/communication field: solar unattended microwave relay station, optical cable maintenance station, broadcast/communication/paging power system; rural carrier telephone photovoltaic system, small communication machine, GPS power supply for soldiers, etc.
4.3 Petroleum, marine, and meteorological fields: cathodic protection solar power systems for oil pipelines and reservoir gates, domestic and emergency power supplies for oil drilling platforms, marine testing equipment, meteorological/hydrological observation equipment, etc.
4.4 Household lamp power supply: such as garden lamps, street lamps, portable lamps, camping lamps, mountaineering lamps, fishing lamps, black light lamps, rubber tapping lamps, energy-saving lamps, etc.
4.5 Photovoltaic power station: 10KW-50MW independent photovoltaic power station, wind-solar (firewood) complementary power station, various large parking plant charging stations, etc.
4.6 Solar buildings Combining solar power generation with building materials will enable large buildings in the future to achieve self-sufficiency in electricity, which is a major development direction in the future.