Solar power generation is divided into solar thermal power generation and photovoltaic power generation, regardless of production and sales, development speed and development prospects, solar thermal power generation can not catch up with photovoltaic power generation. Perhaps because photovoltaic power generation is more widespread and less exposed to photothermal power generation, what is usually referred to as solar power generation is often referred to as solar photovoltaic power generation, or photovoltaic for short.
Solar photovoltaic power generation is based on the principle of photovoltaic effect, using solar cells to convert sunlight energy directly into electricity. Whether for stand-alone use or grid-connected power generation, photovoltaic power generation systems consist of three main components: solar panels (modules), controllers and inverters, which are mainly composed of electronic components, but do not involve mechanical parts.
Solar photovoltaic power generation is divided into three types according to the delivery method: stand-alone photovoltaic power generation, grid-connected photovoltaic power generation, and distributed photovoltaic power generation.
Stand-alone photovoltaic power generation
Stand-alone photovoltaic power generation system is also called off-grid photovoltaic power generation system. It mainly consists of solar modules, controllers, and batteries. To supply power to AC loads, an AC inverter is also required.
Grid-connected photovoltaic power generation
A grid-connected PV system is a system in which the DC power generated by the solar modules is converted by a grid-connected inverter into AC power that meets the requirements of the utility grid and is then directly connected to the public grid. Grid-connected photovoltaic power generation system has centralized large-scale grid-connected photovoltaic power station is generally national power station, the main feature is the power generated directly to the grid, by the grid unified deployment of power supply to users. But this kind of power station investment, construction period is long, covers a large area, the development is relatively difficult. And decentralized small grid-connected photovoltaic system, especially photovoltaic building integrated power generation system, due to the advantages of small investment, fast construction, small footprint, policy support, etc., is the mainstream of grid-connected photovoltaic power generation.
Distributed photovoltaic power generation
Distributed photovoltaic power generation system, also known as decentralized power generation or distributed energy supply, refers to the configuration of smaller photovoltaic power supply systems at or near the user site to meet the needs of specific users, to support the economic operation of the existing distribution grid, or to meet the requirements of both at the same time.
The basic equipment of distributed photovoltaic power generation system includes photovoltaic modules, photovoltaic square brackets, DC sink boxes, DC distribution cabinets, grid-connected inverters, AC distribution cabinets and other equipment, in addition to power supply system monitoring devices and environmental monitoring devices. Its operation mode is that under the condition of solar radiation, the solar cell array of PV power generation system converts the solar energy output into electrical energy, and sends it to the DC distribution cabinet through the DC sink box centrally, and the grid-connected inverter inverts it into AC electricity to supply the building's own load, and the excess or insufficient electricity is regulated by connecting to the grid.
