Every Kw that goes out onto the grid from these solar fields is worth a certain dollar amount that your utility company will apply as a credit onto your electrical bill. 

These credits are going to show up on your bill each month and cancel out what you would typically owe the utility. 

So, for example, if you have a $200 Utility Bill with $200 of Credit, instead of paying $200 bucks to the utility that month you will pay $170 that goes directly to the solar program.