Different solar producers refer to different warranty conditions and thy can be rather confusing. Solarstone has three different types of warranty.
2-year Installation Warranty. Installation warranty is imposed on the panels and inverter at the very moment the system is handed over to the Client. The most essential is to determine that all parties understand that the system (modules + field cables + inverter) performs as designed with full functionality and integrity. Whatever failures that could be caused as a result of poor installation must be detected within this period.
10-year Product Warranty. Product warranty guarantees that the modules last minimum of 10 years – they produce electricity and perform as roofing material. The framing is intact and the clamps function as on day 1. There are no seepages (except occurrence of condensed water as is typical to tiled roofs) or other failures that might expose risks to the building. 10-year warranty usually coincides with the length of the Product Warranty of different inverter manufactures.
25-year Productivity Warranty. The productivity of solar modules is not constant over time continuum. The decline in production output is typically 0,5% per year. Guaranteed electrical production for 25 years is at 80% of rated power output.