Estimate solar value and payback
| Estimated annual production | 6,500 kWh |
| Used on site | 4,225 kWh |
| Exported to grid | 2,275 kWh |
| Estimated annual value | $897 |
| Simple payback | 11.1 years |
Important: this does not include financing, tax credits, maintenance, system degradation, battery costs or future tariff changes. Production depends on roof orientation, shade and local weather.
Why self-consumption matters
Electricity used in the home often avoids a different price from electricity exported to the grid. Entering both rates makes the estimate more useful than treating all production as identical.
What this does not model
This is a simple cash-payback estimate. It does not forecast tariff changes, performance degradation, financing, incentives, maintenance or battery economics.
Example: a 4 kW rooftop system
Annual output = system size × specific yield. A 4 kW system with an example yield of 1,100 kWh per kW per year produces about 4,400 kWh. Electricity used in the home is worth the full retail price; electricity exported is usually paid at a lower rate.
| Share used at home | Value at $0.25 used / $0.08 exported | Payback on $7,000 |
|---|---|---|
| 30% | $576 a year | 12.1 years |
| 50% | $726 a year | 9.6 years |
| 70% | $876 a year | 8 years |
Using more of the output at home, for example by running appliances in daytime, shortens payback more than a small change in system price. Specific yield depends on location, roof angle and shading; check a local estimate before relying on the result.