When light hits your solar panel system, the cells allow the particles of light (photons) to knock electrons free of the atoms in the semi-conductor material. These electrons are then captured in the form of an electric current.
The electric current that is captured form the photovoltaic cells is Direct Current (DC). An inverter is used to convert this current to Alternating Current (AC), which is the standard used by all electrical appliances.
During the course of the day, you will use a portion of the electricity generated to run your lights and household appliances. Even though you're still using the usual amount of electricity in your home, your power bill shrinks and, because your electricity is produced without pollution, your carbon footprint is reduced.
Once you've used what you need, the remainder is sent to the grid. Because this electricity can be used to power other residents' appliances, you will receive credits for this electricity. In this way, you receive the full benefit from your residential solar power system.