Data approachEIA rates · NREL sun hours · 2026 federal policy · methodology
A typical 8 kW solar system in Idaho costs about $24,000 installed in 2026 and saves roughly $960 in year one, for a simple payback near 25 years. That estimate includes no federal credit, because the 30% homeowner credit ended for systems installed after December 31, 2025. Idaho’s state income-tax deduction for solar still applies, though its effect is modest.
Last updated: October 4, 2026. Prices, utility export credits and tax rules change; check current figures before you sign a contract.
Idaho gets good sun, about 5.0 peak sun hours a day (NREL), but has some of the lowest residential electricity prices in the country. The EIA’s 2024 state average was about 11.5¢/kWh, and more recent monthly readings have run higher. Idaho Power’s switch to net billing also cuts what exported solar earns. Cheap grid power plus a lower export credit is why payback is long here. This guide shows every input so you can test it against your own quote. The full model is on our methodology page, and state data is on the Idaho solar page.
💰 System Cost
What Does Solar Cost in Idaho in 2026?
A typical 8 kW Idaho system costs about $24,000 installed at our $3.00-per-watt model price, with no federal credit to subtract for 2026 installations.
System size
Panels (400 W)
Installed cost at $3.00/W
Federal credit (2026 install)
6 kW
15
$18,000
$0
8 kW (typical ID)
20
$24,000
$0
10 kW
25
$30,000
$0
Assumptions: $3.00/W is a modeled US blended price, not a quote. Marketplace averages can run lower and full-market medians higher, so use real quotes. Excludes batteries, roof work and service upgrades.
Until December 31, 2025, homeowners could claim 30% of that cost under §25D, which would have brought a $24,000 system down to $16,800. The One Big Beautiful Bill Act (Public Law 119-21, signed July 4, 2025) ended the credit for later installations. Older Idaho quotes and articles showing a “cost after tax credit” do not apply to a 2026 purchase.
Prices vary by market. Competitive metro areas such as the Treasure Valley tend to have more installers to compare than remote parts of northern and eastern Idaho. Ask whether the quote includes utility interconnection fees and any required electrical upgrades. If you finance, compare the cash price with the financed price, because many solar loans build a dealer fee into the system price. The solar loan calculator shows total interest.
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🏛️ Incentives
Which Idaho Solar Incentives Can You Still Use in 2026?
For a system you own and install in 2026, the main incentive left in Idaho is the state income-tax deduction for residential alternative-energy devices. It is worth roughly $1,000 on a typical system. The federal homeowner credit is gone.
Incentive
Status for a 2026 install
Value on a $24,000 system
Federal §25D credit (30%)
Ended after Dec 31, 2025
$0 (a 2025 install would have received $7,200)
Idaho alternative-energy deduction
Available
Deductions of $5,000 (year 1, capped) + $4,800 × 3 (years 2–4) = $19,400; worth about $1,000 in state tax
Lease / PPA (§48E, claimed by the installer)
Available for projects meeting the federal deadlines
Depends on contract price
USDA REAP (farms, rural small businesses)
Program exists; funding rounds vary
Grant share varies by award
Deduction schedule: 40% of cost in year one and 20% in each of the next three years, capped at $5,000 per year. Tax value assumes Idaho’s flat income-tax rate of about 5.3% (the 2025 rate; confirm the current rate with the Idaho State Tax Commission). This is not tax advice.
With the deduction included, the effective cost falls to about $23,000 and payback to roughly 24 years, so it helps only a little.
Who can still use a federal credit? Idahoans whose systems were completed in 2025 claim 30% on the 2025 return (Form 5695), and unused §25D credit from earlier years can still carry forward. Businesses and farms that own solar may still use §48E if the project meets the law’s construction-start or placed-in-service deadlines, plus MACRS depreciation, and rural operations can apply for USDA REAP grants. Tax-exempt and government entities can use elective (“direct”) pay for §48E within the same deadlines. For the full timeline, see our federal solar tax credit guide. Check DSIRE for any local or utility programs.
📋 Key Insights
Is Solar Worth It in Idaho? Savings and Payback
An 8 kW system saves about $960 in year one. Whether it is worth it depends mostly on how fast your electricity rates rise: with 3% annual increases the model shows about $8,900 of net savings over 25 years, and with flat rates it falls about $1,300 short of paying back.
Worked example (modeled, not a real customer):
Input / result
Value
System size
8.0 kW
Peak sun hours (NREL)
5.0 per day
Annual production (kW × sun × 365 × 0.82)
~11,970 kWh
Electricity rate (EIA 2024 state average)
11.5¢/kWh
Bill offset under net billing (modeled assumption)
0.70
Year-1 savings (11,970 × $0.115 × 0.70)
~$960
Installed cost
$24,000
Simple payback ($24,000 ÷ $960)
~25 years
25-year bills without solar (3%/yr increases)
~$50,200
25-year net savings (3%/yr rates, 0.5%/yr degradation, minus cost)
~$8,900
Data visualization
Cumulative cash flow, 8 kW Idaho system (no federal credit). Breakeven arrives in year 20 if rates rise 3% a year and never arrives within 25 years if rates stay flat. Modeled with NREL PVWatts sun hours and EIA 2024 Idaho rate of 11.5 cents per kWh.
Chart summary: With electricity rates rising 3% a year, the modeled 8 kW system breaks even in about year 20 and ends year 25 roughly $8,900 ahead. If rates stay flat, savings never quite cover the $24,000 cost, ending about $1,300 short after 25 years. Both lines assume 0.5% yearly panel degradation, no federal credit and no battery, and the numbers come from the worked example above.
By monthly bill (same Idaho assumptions):
Monthly bill
System size
Installed cost
Year-1 savings
Payback
25-yr net savings
$100
7.0 kW
$20,900
~$840
~25 yrs
~$7,700
$150
10.5 kW
$31,400
~$1,260
~25 yrs
~$11,600
$200
13.9 kW
$41,800
~$1,680
~25 yrs
~$15,400
Assumptions: system sized to annual usage at 11.5¢/kWh and 5.0 sun hours; year-1 savings = bill × 12 × 0.70; $3.00/W; 3% annual rate escalation; 0.5% annual degradation; no federal credit. Bills are the energy bill only; fixed charges are not offset.
The two biggest levers are price and how much solar you use yourself. The 0.70 offset is our modeling assumption, not a utility figure, so test it against your own load profile.
Data visualization
Simple payback in years, 8 kW Idaho system. At $3.00 per watt and a 70% bill offset, payback is 24.9 years. Formula: installed cost divided by 11,972 kWh times 11.5 cents per kWh times offset. Sources: NREL PVWatts, EIA 2024.
Chart summary: At the base case of $3.00/W and a 70% bill offset, simple payback is about 25 years. A cheaper $2.60/W quote shortens it to about 22 years, while $3.40/W lengthens it to about 28. Raising self-use so that solar offsets 80% of the bill cuts payback to about 22 years at $3.00/W, and a 60% offset stretches it to about 29. Rates matter too: at the July 2026 EIA monthly average of about 13.7¢/kWh, the same system would save about $1,150 in year one and pay back in roughly 21 years.
Idaho Power, the state’s largest utility, moved new solar customers to real-time net billing in 2024. Solar you use as it is produced offsets energy you would otherwise buy at the retail rate. Exported energy earns a financial credit at a time-differentiated export credit rate (ECR).
The Idaho Public Utilities Commission (IPUC) reviews that export credit every year, with updates taking effect June 1. In its October 2025 decision on the 2025–26 update, the IPUC limited the size of the cut. Approximate approved values for non-legacy customers were about 15.7¢/kWh for summer on-peak hours, 3.4¢ for summer off-peak and 2.9¢ for the non-summer season, versus the roughly 14¢, 1.8¢ and 1.0¢ the utility had requested. Grandfathered “legacy” customers who applied before late 2020 are on a different structure. Check Idaho Power’s current Schedule 6 for the rate that applies to you now, because it changes each year.
That is why our model uses a 0.70 bill offset instead of the higher offset typical of full-retail net-metering states. What it means for you:
Don’t oversize. Sizing somewhat below 100% of annual usage usually improves returns, because extra kWh are more likely to be exported at the lower credit.
Shift flexible loads to daylight hours to raise the share of solar you use yourself.
Batteries rarely pay for themselves on savings alone at Idaho’s rates. A 13.5 kWh-class battery often costs roughly $12,000–$16,000 installed, and homeowner batteries installed in 2026 get no federal §25D credit. Consider one for backup, especially in rural areas with frequent outages.
Rocky Mountain Power (eastern Idaho), electric co-ops and municipal utilities set their own terms. The IPUC approved a time-differentiated export credit for Rocky Mountain Power in late 2025, so do not assume Idaho Power’s numbers apply. Before signing, get your utility’s current export credit in writing. The solar net metering calculator models different export rates. For neighboring states, see Utah, Oregon and Nevada.
📋 Key Insights
How Do You Choose a Solar Installer in Idaho?
Pick an installer who prices your system competitively in dollars per watt and models savings on your utility’s actual export credit, without a federal credit.
Quotes: Get at least three written quotes. Compare the price per watt, the panel and inverter models, and whether interconnection fees and permits are included.
Honest savings model: Ask for year-one savings calculated with your utility’s current export credit, not the full retail rate. Reject any 2026 proposal for a system you would own that subtracts a 30% federal tax credit.
Licensing and insurance: Confirm the company’s Idaho electrical licensing through the Idaho Division of Occupational and Professional Licenses, and ask for proof of general liability and workers’ compensation insurance.
Warranties: Panels commonly carry 25-year product and performance warranties. Inverters usually carry 10–25 years, depending on type. Look for an installer workmanship warranty of at least 10 years.
Leases and PPAs: A third-party owner may still qualify for §48E under the federal deadlines and may pass some of the benefit on as a lower price. Compare its price per kWh with your own rate using the lease vs. buy calculator.
Sources: IRS guidance on §25D and Public Law 119-21; EIA state residential electricity prices (EIA-861, 2024, and Electric Power Monthly); NREL PVWatts solar resource; Idaho Public Utilities Commission orders in Case IPC-E-25-15 and its October 2, 2025 news release; IPUC November 2025 release on Rocky Mountain Power; Idaho State Tax Commission (alternative-energy deduction); DSIRE; USDA Rural Development (REAP). Installed prices are modeled; confirm with local quotes. Model details: methodology.
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For most owners it is a long-term, modest return rather than a quick win. In our model an 8 kW system costs about $24,000, saves roughly $960 in the first year and takes about 25 years to pay back on a cash purchase. If electricity rates rise about 3% a year, modeled 25-year net savings are about $8,900. If rates stay flat, the system does not fully pay for itself within 25 years. Idaho has some of the lowest residential electricity prices in the country, and Idaho Power's net billing pays less for exported power, so solar works best for homes that use much of their output during the day. Get quotes and model your own bill before deciding.
Our model uses $3.00 per watt, so a typical 8 kW system (20 panels of 400 W) costs about $24,000 installed, a 6 kW system about $18,000 and a 10 kW system about $30,000. Real quotes vary by installer, equipment and location, and the 2026 price has no federal credit subtracted. Excludes batteries, roof repairs and electrical service upgrades. Compare at least three written quotes on a dollars-per-watt basis.
The 30% federal Residential Clean Energy Credit (§25D) ended for homeowner systems installed after December 31, 2025, under Public Law 119-21. Systems completed in 2025 are claimed on the 2025 return, and unused credit from earlier years can carry forward. Idaho still offers a state income-tax deduction for residential alternative-energy devices: 40% of the cost in year one and 20% in each of the next three years, capped at $5,000 per year, worth about $1,000 on a $24,000 system at a rate near 5.3%. Farms and businesses may use USDA REAP grants and the §48E credit within its deadlines. This is not tax advice; confirm with a tax professional and the Idaho State Tax Commission.
Since 2024, new Idaho Power solar customers are on real-time net billing. Solar power you use as it is produced offsets energy you would buy at the retail rate, while power you export to the grid earns a financial credit at a time-based export credit rate that the Idaho Public Utilities Commission updates each June 1. Exports are worth much less than retail power, so using more of your own solar (daytime loads, EV charging, a heat-pump water heater) improves savings. Customers of Rocky Mountain Power, electric co-ops and municipal utilities have different rules, so confirm your utility's current tariff in writing.
Divide your annual electricity use in kWh by about 1,500 to estimate system size in kW (5.0 sun hours × 365 days × 0.82 system efficiency). A home using about 12,000 kWh a year needs roughly 8 kW, or about 20 panels of 400 W. Under net billing, sizing slightly below 100% of annual use often improves returns, because each exported kWh earns less than each kWh you use directly.
Idaho solar by electric bill
See system size and payback for common monthly bills in Idaho.
12.96¢/kWh — Idaho average residential price. Source: EIA Electric Power Monthly, Table 5.6.B (year-to-date through July 2026), residential average retail price (July 2026) (EIA)
Solar production
5 peak sun hours/day × 0.82 system derate. Approximate state-average daily solar resource (peak sun hours) based on NREL solar resource data (NSRDB); not location-specific — use NREL PVWatts for an address-level estimate. (NREL PVWatts)
Installed price
$3.00 per watt before incentives. Blended 2026 US residential installed price used by this site; EnergySage marketplace reported about $2.60/W (mid-2026); full-market medians are higher.
Federal tax credit
$0 for homeowner-owned systems installed in 2026 — the 30% §25D credit ended Dec 31, 2025 (IRS)
Net metering
Net billing / reduced export credit — solar assumed to offset 70% of the bill. Idaho Power moved to real-time net billing in 2024, crediting exports below retail.
Estimates only — not tax, legal or financial advice. Get at least three installer quotes and confirm incentives with your utility and a tax professional.