Photovoltaic power generation systems are usually divided into grid-connected power generation and off-grid power generation. Grid-connected power generation is to convert the received solar radiation energy into high-voltage direct current through high-frequency direct current conversion through photovoltaic modules, and output alternating current after inverter inversion. It is connected to the national grid; off-grid power generation is self-consumption and local consumption, and the application is more flexible.

The conventional photovoltaic power generation system is mainly composed of photovoltaic array, charge and discharge controller, energy storage equipment or inverter (inverter control integrated machine can be used in this link, which is convenient and more efficient), load, etc. When light is irradiated on the photovoltaic array, the light energy is converted into electrical energy. The output current of the photovoltaic array is unstable due to the influence of the environment. It needs to be converted into a stable current by a converter before it can be loaded on the battery. After charging, the battery supplies power to the load. In the case of grid-connected electricity sales, there is no need for a battery, but a grid-connected inverter converts DC current into AC current and sells it on the grid. That is to say, off-grid photovoltaic power generation systems must use batteries for energy storage, while grid-connected photovoltaic systems do not necessarily require it.
In fact, in real life, because the off-grid photovoltaic power generation system is not limited by geographical areas and has a wide range of applications, it can be installed and used as long as there is sunlight, so it is very common, such as solar street lights, traffic lights, agricultural insecticide lamps, etc., especially It is suitable for some remote areas without power grids, isolated islands, fishing boats, outdoor breeding bases, etc. that are not covered by the power grid, and can also be used as emergency power generation equipment in areas with frequent power outages.