Model simple payback, break-even, NPV, IRR, levelized cost, degradation, rate escalation, export value, maintenance, and optional financing.
Change the inputs that matter to your decision. Optional assumptions stay collapsed until you need them.
Start with a real proposal and tariff; this model is for comparing scenarios, not predicting a guaranteed return.
Defaults use no federal residential credit after the 2025 termination. Enter only incentives applicable to your installation and tax situation.
Break-even in year 12; modeled NPV is $5,885 over 25 years.
$26,886 cumulative net cash flow and $0.11/kWh modeled levelized cost.
| Year 1 | $1,3389,636 kWh · cumulative -$16,662 |
|---|---|
| Year 2 | $1,3719,588 kWh · cumulative -$15,291 |
| Year 3 | $1,4049,540 kWh · cumulative -$13,887 |
| Year 4 | $1,4389,492 kWh · cumulative -$12,450 |
| Year 5 | $1,4729,445 kWh · cumulative -$10,977 |
Scenario model only. Validate proposal production with site-specific PVWatts output and verify degradation, maintenance, export compensation, financing, taxes, and incentives independently.
Practical notes about the inputs, assumptions, and result.
Simple payback asks when undiscounted cumulative cash flow crosses zero. NPV discounts future cash flows, so it can be negative even when a project eventually pays back.
Use the tariff's actual compensation for exported electricity. Full retail net metering is 100%; avoided-cost or wholesale compensation may be materially lower.
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