Solar payback in Idaho

4.6 peak sun hours/day average. Residential electricity rate: 12.7¢/kWh.

Estimated payback by system size

Installed cost at 2.75$/W, accounting for 20% system-loss derate (inverter, wiring, soiling, temperature).

SystemAnnual kWhAnnual SavingsInstalled CostPayback
4 kW5,376 kWh$682.81$11,00016.1 years
6 kW8,065 kWh$1,024.22$16,50016.1 years
8 kW10,753 kWh$1,365.63$22,00016.1 years

Important notes

No incentives assumed: The federal residential solar investment tax credit ended after 2025. Some states and utilities still offer rebates or performance-based incentives; check with your utility.

Full self-consumption or net metering: Savings assume you use all generation on-site or export at retail rates via net metering. Some utilities buy surplus power at wholesale rates, which would reduce savings.

Your site specifics matter: Roof shade, orientation, system degradation, and your actual utility tariff (demand charges, time-of-use rates, fixed fees) can significantly change payback.

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Electricity rates in Idaho