Let's cut to the chase, most solar panels last between 25 and 30 years before their output drops below an efficient level. For utility-scale solar developers, EPCs, asset managers, and financiers, the performance and durability of photovoltaic (PV) panels directly influence project bankability, return on investment (ROI), and long-term asset valuation. This longevity surpasses that of many other household systems, such as boilers, which usually have a life expectancy of 10 to 15 years. NREL's widely cited meta-analyses of more than 50,000 module‑years of data find median degradation around 0. 5%. Solar panels must operate for many years in a wide variety of extreme environments, from climates with huge temperature fluctuations to high humidity, rain, storms, strong winds, and corrosion from salt in coastal areas.