Sunlight is captured by the solar array as DC power.  After the energy passes through an inverter, the energy is converted to AC power so that it is compatible with home/office energy use.  From the inverter, the solar power passes through the facility’s main electrical panel where the energy is used first.  If there is not enough power produced at any time then power from the electric provider is used from the grid.  If surplus power is generated, the meter literally “runs backwards” providing a utility credit.