MCPCalc

Solar ROI Calculator

Estimate solar payback period and lifetime savings from system costs and energy production.

Scratchpad (not saved)

$
%
kWh
$/kWh
%/year
years

What This Calculator Does

Estimate solar payback period and lifetime savings from system costs and energy production.

It combines System Cost, Incentives, Annual Production, Electricity Rate to estimate Net System Cost, Payback Period, Lifetime Savings.

Formula & Method

Net cost C_n=C_{system}(1-Incentive). Degraded lifetime production is geometric: E_{life}=E_1\cdot\frac{1-(1-d)^Y}{d} (or E_1Y if d=0). Savings S=E_{life}\cdot Rate, payback P=\frac{C_n}{Year1Savings}, ROI =\frac{S-C_n}{C_n}\times100.

Notation used in the formulas: R = Net System Cost; x_{1} = System Cost; x_{2} = Incentives; x_{3} = Annual Production; x_{4} = Electricity Rate; x_{5} = Panel Degradation; x_{6} = Analysis Period.

Method summary: inputs are normalized to consistent units, core equations are evaluated, then secondary values are derived and rounded for display.

Use this calculator for quick scenario analysis. Start with baseline values, change one driver at a time, and compare how sensitive the results are to each input shown above.

Inputs Used

  • System Cost: Used directly in the calculation.
  • Incentives: Used directly in the calculation.
  • Annual Production: Used directly in the calculation.
  • Electricity Rate: Used directly in the calculation.
  • Panel Degradation: Used directly in the calculation.
  • Analysis Period: Used directly in the calculation.

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