If you have financed your system and own it, congratulations! After you have paid off your solar loan, you are producing nothing but clean energy and instant savings, all with a warrantied system that will last for 25+ years.
If you have a solar lease, at the end of the leasing contract you may have a few options depending on the company. The most costly option will be to buy out the system from the leasing company. You could also renew your lease, or you could choose to terminate the lease in which the leasing company will come to remove the panels.