Large scale on-grid PV station refers to the solar power station which is connected with the public power grid and together responsible for power supply. It is an important development direction of solar power generation considering the coming large -scale commercial power generationstage and it will be an integral part of electric power industry. Large ground station is suitable for areas with rich solar energy resources and land resources.

Off grid system mainly refers to a new energy power supply system relying on storage battery as the backup. In the case of sunlight during the day, the solar battery supplies power to the load and stores excess power in the battery; When the sunshine is insufficient or during the night and cloudy days, battery serves as the backup to ensure all power is sent to the load till the next sunny day.