Solar photovoltaic (PV) power generation is based on the photovoltaic effect, using solar cells to directly convert sunlight into electrical energy. Whether used independently or connected to the grid, a PV power generation system mainly consists of three parts: solar panels (modules), controllers, and inverters. These are primarily composed of electronic components and do not involve mechanical parts.
Solar photovoltaic power generation can be classified into three types based on the transmission method: stand-alone photovoltaic power generation, grid-connected photovoltaic power generation, and distributed photovoltaic power generation.
Independent photovoltaic power generation
Stand-alone photovoltaic (PV) systems, also known as off-grid PV systems, mainly consist of solar cell modules, a controller, and batteries. If an AC load needs to be powered, an AC inverter is also required.
Grid-connected photovoltaic power generation
Grid-connected photovoltaic (PV) power generation systems convert direct current (DC) generated by solar panels into alternating current (AC) that meets the requirements of the municipal power grid via a grid-connected inverter before being directly connected to the public power grid. Grid-connected PV power generation systems include centralized large-scale grid-connected PV power plants, typically national-level power plants, whose main characteristic is the direct transmission of generated energy to the grid for unified distribution to users. However, these power plants require large investments, have long construction periods, and occupy large areas, making their development relatively difficult. Distributed small-scale grid-connected PV systems, especially building-integrated photovoltaic (BIPV) systems, are the mainstream of grid-connected PV power generation due to their advantages such as lower investment, faster construction, smaller footprint, and stronger policy support.
Distributed photovoltaic power generation
Distributed photovoltaic (PV) power generation systems, also known as decentralized power generation or distributed energy supply, refer to small-scale PV power generation systems configured at or near user sites to meet the needs of specific users, support the economic operation of existing power distribution networks, or simultaneously meet both of these requirements.
The basic equipment of a distributed photovoltaic (PV) power generation system includes PV modules, PV array supports, DC combiner boxes, DC distribution cabinets, grid-connected inverters, and AC distribution cabinets. Additionally, it includes power supply system monitoring devices and environmental monitoring devices. Its operating mode is as follows: under solar radiation conditions, the PV system's solar cell array converts solar energy into electrical energy, which is then collected by the DC combiner box and fed into the DC distribution cabinet. The grid-connected inverter then converts this electrical energy into AC power to supply the building's own load. Excess or insufficient power is regulated by connecting to the power grid.