A worked example: 8 kW in Idaho
An 8 kW system — about 19 × 425-watt panels — at Idaho's assumed installed cost of $2.45–$3.20 per watt runs roughly $19,600–$25,600 before incentives. At about 1,380 kWh of production per installed kW, it would generate around 11,040 kWh per year. Valuing self-consumed electricity at the assumed $0.11/kWh retail rate and exports conservatively, first-year savings land near $1,001 — a simple payback of roughly 20–26 years.
There is no federal tax credit in that math: the Section 25D residential credit ended for systems installed after December 31, 2025. State or utility incentives, where they exist, would shorten payback from here.
Average cost of solar panels in Idaho by system size
Most Idaho quotes land between 6 and 12 kW. At the state's assumed $2.45–$3.20 per watt, here is what each size costs to install, what it produces, and how long it takes to pay for itself on electricity savings alone — no incentives applied.
| System size | Panels | Installed cost | Annual production | Est. payback |
|---|---|---|---|---|
| 6 kW | 15 | $14,700–$19,200 | 8,280 kWh | 20–26 yrs |
| 8 kW | 19 | $19,600–$25,600 | 11,040 kWh | 20–26 yrs |
| 10 kW | 24 | $24,500–$32,000 | 13,800 kWh | 20–26 yrs |
| 12 kW | 29 | $29,400–$38,400 | 16,560 kWh | 20–26 yrs |
Size should follow your electricity usage, not a round number — these are reference points, not a recommendation. Note that cost per watt rises on smaller systems, because permitting, labor and the inverter do not shrink with the array.
What solar costs per kWh in Idaho
Spread across a 25-year life, with 0.5%/yr panel degradation and no financing cost, solar electricity in Idaho works out to roughly 7.5¢–9.8¢ per kilowatt-hour. The Idaho retail rate this page assumes is 11.0¢. That gap — not the sticker price — is what determines whether solar pays here, and it is why a sunnier state with cheap electricity can be a worse investment than a cloudier one with expensive electricity. See how every state compares on cost per kWh.
Net metering and export rates in Idaho
Idaho has no statewide mandate. Idaho Power has shifted new customers to net billing with exports credited below retail and measured on shorter intervals; other utilities vary.
Export rules are worth reading as an incentive, because they set what every kilowatt-hour you do not use on site is worth — see how Idaho compares with every other state on net metering.
Idaho solar incentives
Idaho offers a state income tax deduction (not a credit) of 40% of system cost in year one plus 20% for three more years, subject to annual caps.
The most valuable program is state income tax deduction (40% year one). With no federal credit for 2026 installs, state and utility programs are now the whole picture — see the full Idaho incentives guide.
What changes an Idaho solar quote?
Equipment, roof condition, electrical upgrades, permitting, labor, system size, batteries and financing can all change the installed price. Savings also depend on the specific utility rate, how much solar electricity the home uses directly, and what the utility pays for exports.
Frequently asked questions
What is the average cost of solar panels in Idaho?
The average installed cost in Idaho runs $2.45–$3.20 per watt before incentives, which puts a 6 kW system at $14,700–$19,200, an 8 kW at $19,600–$25,600, and a 10 kW at $24,500–$32,000. Spread over a 25-year life, that works out to about 7.5¢–9.8¢ per kilowatt-hour, against a Idaho retail rate assumed at 11.0¢.
How much does it cost to install solar panels in Idaho?
Installation is not priced separately — the $2.45–$3.20 per watt above is a turnkey figure covering panels, inverter, racking, labor, permitting and interconnection. What moves it most in ID is roof complexity, whether the main panel needs upgrading, and whether a battery is included. Expect a site visit to change any online estimate, including this one.
How much do solar panels cost in Idaho?
Using an assumed installed cost of $2.45–$3.20 per watt, a typical 8 kW home system in Idaho costs roughly $19,600–$25,600 before incentives. Smaller and larger systems scale roughly with size, though small systems cost more per watt.
Is solar worth it in Idaho?
With Idaho electricity around $0.11/kWh and production around 1,380 kWh per installed kW per year, an 8 kW system could save roughly $1,001 in year one, for a simple payback of about 20–26 years with no federal credit. Whether that is "worth it" depends on your rate plan, export compensation, roof, and how long you plan to stay in the home.
How many solar panels do I need in Idaho?
It depends on your electricity usage, not your roof. At Idaho's assumed 1,380 kWh per installed kW, a 6 kW system (about 15 panels at 425 watts) generates roughly 8,280 kWh a year, and a 10 kW system (about 24 panels) roughly 13,800 kWh. Compare that against your annual kWh from a utility bill — our calculator sizes it from your monthly bill in about a minute.
Does Idaho have net metering?
Idaho has no statewide mandate. Idaho Power has shifted new customers to net billing with exports credited below retail and measured on shorter intervals; other utilities vary.
What solar incentives does Idaho offer in 2026?
Idaho offers a state income tax deduction (not a credit) of 40% of system cost in year one plus 20% for three more years, subject to annual caps. Note that the federal Section 25D residential credit ended for systems installed after December 31, 2025, so state, local and utility programs are now the main incentives for purchased systems.
Is there still a federal solar tax credit in Idaho?
No — the 30% federal residential clean energy credit (Section 25D) ended for systems installed after December 31, 2025 under the One Big Beautiful Bill Act. Leased or PPA systems may still benefit indirectly because the system owner can claim the commercial 48E credit through 2027.
Use this as a starting point
This page provides broad state assumptions, not a current market survey or binding quote. Before purchasing, verify applicable incentives, utility rules, installer licensing, warranties and financing terms.
Where these numbers come from
State assumptions are informed by public data and reviewed periodically (September 2026):