Solar Payback Period & ROI

Calculate simple payback, 25-year cumulative savings, and NPV with the federal tax credit.

System cost — gross (before incentives) ($)

Federal Investment Tax Credit (%)

30% federal ITC current as of 2026 — verify at irs.gov for your situation.

State / local incentive ($)

Annual production (kWh/year)

Use the Panel Sizing Calculator to estimate this.

Electricity rate ($/kWh)

US average ≈ $0.16/kWh. Check your utility bill.

Net metering type

Annual electricity rate increase (%)

Discount rate / cost of capital (%)

Used for NPV calculation. Use your mortgage rate or expected investment return.

— year payback

Net cost after incentives —

Federal ITC savings —

Year 1 annual savings —

Simple payback period —

Break-even year (with rate escalation) —

25-year cumulative savings —

Net Present Value (NPV) —

Lifetime ROI —

25-Year Savings Projection

Assumes 0.5%/year panel degradation · Rate escalation and discount rate as entered above.

Year	Production (kWh)	Annual Savings ($)	Cumulative Savings ($)