Solar
Solar Panel Degradation Calculator
Estimate how much solar panel capacity remains after years of annual degradation.
kW
%/year
Use the degradation rate from the module warranty or manufacturer data.
years
Estimated Remaining Capacity
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Estimated equivalent system capacity after annual degradation.
Capacity Remaining
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Total Capacity Loss
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Capacity Lost
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Annual Degradation Rate
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| Year | Remaining Capacity | Capacity Remaining |
|---|
How it is calculated:
Remaining capacity = initial capacity × (1 − annual degradation rate)years.
This treats degradation as a compounded annual reduction. For example, a 0.5% annual degradation rate means each year’s remaining capacity is 99.5% of the previous year’s capacity.
Actual degradation can vary by module technology, climate, installation conditions, manufacturing quality and operating history. Some module warranties also specify a larger first-year degradation followed by a lower annual rate; where available, use the manufacturer’s warranty curve for detailed performance assessment.