PV power generation system is mainly composed of PV modules, PV cells, inverters, DC transmission and transformer equipment, etc. PV power plants can be divided into centralized PV power plants and distributed PV power plants. Centralized photovoltaic power plant refers to the use of collector equipment to connect a certain power of solar energy directly to the grid system, and through the operation of multiple inverters for grid-connected distributed photovoltaic power generation.
1, rooftop distributed photovoltaic power generation
Rooftop distributed photovoltaic power generation refers to the use of solar energy on the roof, through the photovoltaic module to collect solar energy (regardless of light intensity) for power generation a form of power generation. The advantage of rooftop distributed photovoltaic power generation is that the system is simple to build, easy to maintain, and can obtain higher power generation revenue can be linked to the grid power generation revenue). Because of the existence of shade on the roof, rooftop distributed photovoltaic power generation occupies relatively little land resources.
2、Ground-based distributed photovoltaic power generation
Ground distributed photovoltaic power generation system mainly includes rooftop photovoltaic system and ground distributed photovoltaic power generation two forms. The basic principle of rooftop distributed photovoltaic system is to use rooftop photovoltaic modules to reflect sunlight to the roof without installing brackets, producing photovoltaic modules to generate electricity. Currently, common rooftop distributed PV systems include ground-based monocrystalline silicon photovoltaic power plants (SMD) and polycrystalline silicon rooftop photovoltaic power plants (SMD) and other series. Ground-based distributed photovoltaic power generation systems are generally provided for home users (such as microgrids), enterprises and institutions, and other customers; ground-based monocrystalline silicon photovoltaic power plants (SMD) are generally installed on residential rooftops (2-3 MW photovoltaic power plants can be selected depending on the number of users and location). They are mainly used on the roofs of public buildings, residential buildings and industrial and mining enterprises in cities, and also in less economically developed areas such as rural areas and rural areas; polycrystalline distributed cell power plants (SMD) are usually installed on the roofs of residential homes and industrial plants. It is mainly used on the roofs of industrial, commercial and residential houses and industrial and mining enterprises. Ground distributed photovoltaic power generation system and ground monocrystalline silicon photovoltaic power station difference mainly lies in: ① photovoltaic modules are generally made of monocrystalline silicon wafers; ② do not need to install brackets and the use of independent construction of power generation devices, etc.
3, urban rooftop photovoltaic power generation
Photovoltaic power generation technology has been rapidly promoted in the city, not only to meet the demand of urban residents for energy, but also has the advantages of clean and environmental protection. In recent years in the city to build a variety of rooftop power station investment scale has far exceeded the PV power plant itself can bring income. Due to the energy loss caused by the insulation of the building and other factors, as well as the energy saving problem caused by the building's own load has become one of the biggest problems plaguing modern urban buildings, urban rooftop photovoltaic technology is one of the most economical and effective ways to use energy to build large rooftop photovoltaic power projects in urban residential areas. Generally, large rooftop power plants use mostly polycrystalline silicon modules with a silver coating on the surface of the modules, which are fixed to the roof wall to generate heat for power generation. By silver plating on the surface of the panel can make the panel to generate heat to generate electricity.
4, cell roof photovoltaic power generation
Solar panels are installed on the roof of a cell or other building, and the power installed is generally between 2 kW and 40 kW. This form of photovoltaic installation cost less and will have more light in the daytime. Installation is usually done by mounting brackets on the building's exterior walls or by erecting cable tunnels on the roof. Depending on the type of PV module on the building's roof, the cost ranges from $5 to $10/KW. The cost of this form is typically 10% to 15% of the building's annual electricity consumption. This approach is mainly applicable to residential roof mounted PV power generation system.
5, the power distribution system in the power plant system
Distributed photovoltaic power generation system electricity is usually provided by the distribution system of the photovoltaic power generation system. Distributed photovoltaic power station due to the number and scattered, distribution system and very complex, so the distribution system must have reliability, stability, economy and maintainability. This requires the system to be designed with full consideration of the reliability and stability of the system, and the power transmission equipment, distribution equipment and power supply system to be unified and coordinated as much as possible without incurring additional costs.