With a solar system generating the electricity you use in your home or business, all of the charges for usage are eliminated. You will still have a monthly meter charge, and demand charges if you are a business in certain utility districts, but your bill is going to be drastically reduced.
Since the solar system only loses about a half of a percent of output year to year, and the electric rates go up 3-7% per year, if you had enough roof space to cover your bill when it was installed, your first year savings should continue long into the future.
It is always good to know what your future costs will be when you are in business. To know that your future electric bill will be very low is very good.