Lease and power purchase agreements
The warranties are handled by the third party company who will maintain the system for the full term of the agreement.
Purchased systems (cash or loan) - There are several different warranties involved:
Workmanship Warranty Provided by the installer. It covers the installation workmanship. Lengths vary by State and provider.
Equipment Warranty Provided by the manufacturer. It covers the manufactured equipment (modules & inverters) from defects. Lengths vary from 5 to 25 years.
Production Warranty Provided by the module manufacturer. It covers how much power loss is expected over the life of the module.