Modern solar panels degrade at 0. 7% annually according to NREL's 2024 comprehensive study of over 54,000 systems. Solar panel degradation is not a single process but a combination of mechanisms that reduce power output gradually over decades. This calculator provides estimates for informational purposes only. Actual solar production, savings, and payback periods depend on site-specific conditions including. According to NREL data, modern crystalline modules degrade at an average rate of 0. The panels installed in dry, hot, desert places where ultraviolet radiation is especially harsh show the highest rates of. The solar panel degradation rate is the annual percentage drop in energy output. 8% per year, meaning after 25 years, you can expect about 80–90% of original efficiency remaining. 5% of their output every year — which sounds minor until you do the math over a 25-year warranty period.
