Solar payback in Rockford, IL
The rate is the state average, not the city's utility tariff. It is the mean of monthly prices from 2025-08 through 2026-07. The system is sized for average state household use.
Solar simple payback
| System size | 6.3 kW |
|---|---|
| Installed price | $3.62/W |
| Gross cost | $22,780 |
| Annual production | 8,630 kWh |
| Annual value | $1,638 |
| Simple payback estimate | 13.9 years |
Installed price uses the national median, n = 61,712 systems, from Berkeley Lab Tracking the Sun (systems installed in 2025, in 2025 dollars, before incentives).
System size = annual household use divided by local annual yield. Gross cost = size in watts × installed price per watt. Annual value = annual production × the state electricity rate in dollars per kWh. Simple payback = gross cost divided by annual value.
The federal 25D credit ended for systems installed after Dec 31 2025. State and utility incentives are not included. This estimate values all production at retail, with no financing, maintenance, degradation, rate changes or discounting. Actual export payments and roof conditions can change the result. Figures are rounded. Sources and limits.
Adjust in the solar calculator