Solar Payback Estimate: How Solar Payback Map Calculates It Without Selling Leads

A public, conservative method for residential solar payback: production, electricity rates, installed cost, incentives, and export-credit policy.

The full formula, every assumption, and why we would rather under-promise. We walk through generation, rates, install cost, and policy.

Key takeaways

Solar generation: NREL PVWatts-style production modeling.

Electricity value: residential rate context from public utility and energy datasets.

Installed cost: national and state cost context from research datasets.

Solar payback estimate, in one sentence

A solar payback estimate is the number of years it takes for bill savings and eligible incentives to recover the net installed cost of a rooftop system.

Solar Payback Map treats that number as a screening tool, not a quote. If the estimate looks weak before roof-specific details, the homeowner should know that before entering a sales funnel.

Solar payback formula used by Solar Payback Map

The model starts with annual production, multiplies it by local electricity value, adjusts for export-credit policy, then compares that savings estimate with net installed cost.

Solar payback sources and assumptions

The model favors public sources over installer-marketplace assumptions. That means visible source labels and review dates are part of the product, not footnotes.

Why a solar payback range is more honest

A precise-looking payback number hides roof angle, shade, financing, usage, future rates, degradation, and tenure. A range is less tidy, but it better matches how homeowners actually make the decision.