Solar savings start with two prices, not one.
A kWh used at home and a kWh exported to the grid can have very different values. A useful solar estimate keeps them separate.
Start with site-specific production
Roof direction, shade, equipment, climate and available space affect production. Use a documented production estimate for the property. System size alone is not a promise of annual output.
Separate self-use from exports
Electricity used directly in the home may avoid a retail purchase. Exported electricity is valued under the applicable utility agreement. Do not assume every exported kWh earns the retail price. Your household schedule and storage can affect the split.
Include the costs that remain
Solar may not remove fixed utility charges. Budget for maintenance and future equipment work, and consider financing separately. Enter only confirmed incentives in a simple payback calculation.
Understand what payback leaves out
Simple payback divides upfront cost by annual net benefit. It does not account for the timing of cash flows, degradation, future rate changes or replacement costs. Use it to compare scenarios and prepare questions for an installer, then review a full proposal.
Put the idea into numbers.
Open the calculatorHAUSE Energy · Reviewed September 8, 2026. For current program rules or prices, use your utility’s published documents and the regional source guide.