Light from the sun carrying photons which are particles of sunlight. These photons come in contact with the Solar Cells contained inside the panels on your roof.
Solar Cells convert the photons into electrons of DC (Direct Current) electricity
Electrons become excited and will flow out of the cells in your solar panels and into a device called an inverter.
An inverter converts the DC into AC (Alternating Current) which your home devices can use
Utility companies will measure electricity use of the home and electricity produced by your modules.
When your panels produce more electricity than you can use the excess power is fed back to the grid and your meter will actually begin to (orange)SPIN BACKWARDS! The more you produce the more credit will be accumulated with your utility company thereby reducing not only your current but FUTURE utility charges!. This process is called net metering