Solar Degradation Calculator

Estimate solar panel output decline over a 25-year lifespan.

Year 0 Production

kWh/yr

First Year Degradation

Annual Degradation

System Lifetime

years

Electricity Rate

$/kWh

Tab to move between fields

Final Output %

86.9%

Final Year Output

8,689 kWh

≈ 10 months of home electricity

Lifetime Production230,848 kWh

Revenue Lost to Degradation$2,873.00

How to Use This Calculator

Enter the panel's initial rated power output in watts.
Set the first-year degradation rate (typically 2–3% for most panels).
Input the annual degradation rate after year 1 (typically 0.5–0.7%/year).
Enter the number of years to project.
Review the remaining power output and cumulative energy production loss over the system life.

How the result changes with System Lifetime

Year 0 Production: Initial annual production at rated capacity.
First Year Degradation: Light-induced degradation in the first year (typically higher).
Annual Degradation: Annual output degradation rate after the first year.
System Lifetime: Number of years to project output.
Electricity Rate: Electricity rate for calculating revenue impact.

Identify Input Parameters
4 parameters
Year 0 Production = 10000, First Year Degradation = 2, Annual Degradation = 0.5, System Lifetime = 25 = 5 input(s) provided
Calculate Final Output %
Final Output %
86.9 = 86.9
Calculate Final Year Output
Final Year Output
8689 = 8689
Calculate Lifetime Production
Lifetime Production
230848 = 230848
Calculate Revenue Lost to Degradation
Revenue Lost to Degradation
2873 = $2,873