A solar tracker system is a system and method to integrate the solar cells to a greenhouse. The solar tracker system comprises solar tracker modules that include solar cells, racks, gears, pinons, motors, and mounting brackets to efficiently and conveniently be installed to the roofs and walls of a new greenhouse and/or an existing greenhouse for retrofit application. Additionally, the solar tracker system uses various sensors to provide real-time conditions to the greenhouse. The method uses actual or system default values to adjust the angle and position of solar cells according to various environmental factors, such as DLI, weather, date, time, direction of sunlight, or type of plant.