Solar 2026
Solar Payback Assumptions That Actually Matter
A solar payback estimate is only useful when you can see the electricity rate, production estimate, incentives, financing cost, and degradation assumptions.
Quick takeaways
- Annual production should be location and roof specific.
- Electricity rate assumptions should be visible.
- Loan fees can hide inside a low monthly payment.
Production is not just system size
A 7 kW system can produce different annual energy depending on roof direction, tilt, shading, climate, inverter choice, and panel layout. Ask for the production model, not just the panel count.
Electricity rates drive savings
The same kilowatt-hour of solar saves more where utility rates are high. Time-of-use plans, minimum bills, and export rates can change the value of each solar kilowatt-hour.
Financing can distort payback
A low monthly payment may include dealer fees, escalators, or a longer term. Compare a cash price and a financed price so you know what the financing is really costing.