The amount of CO2 emissions avoided is contingent upon a system’s geographic location, the size and type (ground mount, rooftop, canopy, etc.). Bearing those factors in mind, the production from a 500 kW DC project located on the East Coast of North America can equate to the avoidance of about 473 tons of carbon dioxide a year. This equates to the greenhouse gas emissions of 90 passenger vehicles driven over the course of one year. A system of the same size in Southwest North America can produce enough energy to equate to the avoidance of 670 tons of carbon dioxide a year.
The EPA has created a very effective CO2 avoidance calculator tool for the general public: https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator