Solar panels convert sunlight into direct current (DC) electricity. An inverter turns it into alternating current (AC) that matches the grid, so it can power your lights, machines and appliances. Electricity you do not use right away can, depending on the system, be stored in a battery or sent to the grid.
The more sunlight your roof receives, and the better the system is designed and installed, the more electricity you produce and the less you buy from the grid.