Quick Answer
Idaho solar incentives in 2026 center on the state Residential Alternative Energy Tax Deduction: 40% of system cost in year one and 20% in each of the next three years, capped at $5,000 per year and $20,000 total. Idaho also offers low-interest state energy loans. Net metering or net billing depends on your utility. The federal residential Section 25D tax credit expired for homeowner-owned systems after December 31, 2025.
Idaho’s solar economics are shaped by one central fact: electricity in the Gem State is cheap. The average residential rate sat near 13.01 cents per kWh in March 2026, according to Choose Energy rate data (2026). That is well below the national average of roughly 18.83 cents per kWh reported by the U.S. Energy Information Administration, Electric Power Monthly (April 2026). Low rates mean each kilowatt-hour of solar saves less money than it would in California or Massachusetts. Proposals must therefore be precise.
The incentive picture also changed sharply on January 1, 2026. The federal Residential Clean Energy Credit under Section 25D expired for homeowner-owned systems. Idaho homeowners can no longer subtract 30% of system cost from their federal tax return. What remains is a thinner state-level stack: the Idaho Residential Alternative Energy Tax Deduction, low-interest state energy loans, and utility-specific compensation rules. For anyone researching solar incentives Idaho, the practical question is not whether incentives exist, but how to combine the ones that do.
This guide covers every active Idaho solar incentive in 2026, the federal policy shift, net metering and net billing rules by utility, real ROI scenarios, and financing options. For the national picture, see our post on solar incentives in the USA 2026. For Idaho-specific proposal modeling, SurgePV design software models utility rates, net billing rules, and payback in one workflow.
Quick Answer
Idaho solar incentives in 2026 center on the state Residential Alternative Energy Tax Deduction: 40% of system cost in year one and 20% in each of the next three years, capped at $5,000 per year and $20,000 total. Idaho also offers low-interest state energy loans. Net metering or net billing depends on your utility. The federal residential Section 25D tax credit expired for homeowner-owned systems after December 31, 2025.
In this guide:
- Latest 2026 status of every active Idaho solar incentive
- How the federal residential tax credit expiration changes the math
- Idaho Residential Alternative Energy Tax Deduction details and examples
- Idaho State Energy Loan Program terms and eligibility
- Net metering vs. net billing by utility: Idaho Power, Avista, Rocky Mountain Power
- Solar costs, payback, and ROI scenarios for Idaho homeowners
- Financing options and who should lease versus buy
- Common mistakes and how to avoid them
Latest Updates: Idaho Solar Incentives 2026
Idaho did not add new solar rebates in 2026. The state’s main financial supports remain the income tax deduction and the state energy loan program. The federal residential tax credit disappeared. The result is a smaller but still predictable incentive stack. Installers who used to lead sales calls with “30% federal tax credit plus net metering” now have to build value around long-term rate protection and the state tax deduction.
Idaho Solar Incentive Status — June 2026
| Incentive | Type | Status | Key Terms |
|---|---|---|---|
| Federal Section 25D residential credit | Federal income tax credit | Expired for new homeowner-owned systems | Systems placed in service after December 31, 2025 do not qualify |
| Federal Section 48E commercial credit | Federal investment tax credit | Active, deadlines apply | 30% for eligible commercial, lease, or PPA systems; construction begin by July 4, 2026 or placed in service by December 31, 2027 |
| Idaho Residential Alternative Energy Tax Deduction | State income tax deduction | Active | 40% year one, 20% years two through four; $5,000/year cap; $20,000 total cap |
| Idaho State Energy Loan Program | State low-interest loan | Active | Up to $30,000; terms 3-7 years; rates 3-7% |
| Idaho sales tax exemption | Tax exemption | Not available | Solar equipment subject to state and local sales tax |
| Idaho property tax exemption | Tax exemption | Not available | Added system value may affect assessment |
| Idaho Power net billing | Utility export compensation | Active for non-legacy systems | ECR: 15.6836¢ summer on-peak, 3.3920¢ summer off-peak, 2.9019¢ non-summer |
| Avista net metering | Utility export compensation | Active | 1:1 retail credit; annual March 31 reset; systems up to 25 kW |
| Rocky Mountain Power net billing | Utility export compensation | Active, changes proposed | Residential systems under 25 kW currently credited at retail rate; Schedule 136 changes pending |
The biggest change for Idaho homeowners is the loss of the federal residential credit. A $25,000 system that qualified for a $7,500 federal credit in 2025 now receives $0 from the federal government for homeowner-owned systems. The state deduction still helps, but it is a deduction against taxable income, not a dollar-for-dollar credit. The cash value is smaller.
Idaho Residential Alternative Energy Tax Deduction
The Idaho Residential Alternative Energy Tax Deduction is the strongest state-level solar incentive available to Idaho homeowners. It is authorized under Idaho Code Section 63-3022C. The statute allows an individual taxpayer who installs an alternative energy device at a residence in Idaho to deduct a percentage of the cost from state taxable income.
The deduction schedule is:
- Year one: 40% of the cost of the solar system
- Year two: 20% of the cost of the solar system
- Year three: 20% of the cost of the solar system
- Year four: 20% of the cost of the solar system
Each year is capped at $5,000. The total cap over four years is $20,000. This means the deduction works best for systems with a gross cost of roughly $12,500 to $25,000. A $25,000 system would generate the full $5,000 deduction in each of the four years.
Important distinction: this is a deduction, not a credit. A deduction reduces taxable income. The actual tax savings equal the deduction amount multiplied by the homeowner’s marginal state income tax rate. Idaho’s top marginal state income tax rate is 5.3% as of 2026, according to Idaho State Tax Commission guidance. A $5,000 annual deduction therefore saves about $265 in state tax per year, or roughly $1,060 over four years. A $20,000 total deduction saves about $1,060 in total.
This is much smaller than a refundable tax credit of the same nominal amount would be. For example, a $5,000 annual credit would be worth $5,000 in cash. The Idaho deduction is worth only the taxpayer’s marginal rate times $5,000. Installers should be transparent about this difference when quoting savings.
To claim the deduction, full-year Idaho residents complete Section B of Idaho Supplemental Schedule 39R and transfer the amount to Form 40. Part-year residents and non-residents use Form 39NR and Form 43. The homeowner must own the system. Leases and power purchase agreements do not qualify.
Idaho State Energy Loan Program
The Idaho Office of Energy and Mineral Resources administers the State Energy Loan Program. It provides low-interest loans for energy efficiency and renewable energy improvements, including solar photovoltaic systems. The program is useful for homeowners who want to own their system but prefer not to pay the full cost upfront.
Program terms reported by EnergySage Idaho solar incentives guide (2026) include:
- Loan amounts up to $30,000
- Terms of 3, 5, or 7 years
- Interest rates capped at 3%, 5%, or 7% respectively
- Can be used for solar panels, insulation, windows, HVAC, and other energy upgrades
Some local installer sources cite a smaller residential loan of up to $15,000 at 4% over 5 years. Program details can vary by funding round and applicant. Homeowners should confirm current terms directly with the Idaho Office of Energy and Mineral Resources.
The loan is not a rebate or tax credit. It reduces the cost of financing rather than the installed price. For a homeowner comparing cash versus loan, the loan can preserve liquidity but adds interest expense. Total loan cost should be included in any payback calculation.
Net Metering and Net Billing by Idaho Utility
Idaho does not have a statewide net metering mandate. Each of the three investor-owned utilities that operate in Idaho has its own tariff approved by the Idaho Public Utilities Commission. Your utility territory determines whether you receive full retail net metering or lower-rate net billing.
Idaho Power Net Billing
Idaho Power serves most of southern Idaho, including Boise, Twin Falls, Pocatello, and much of the Snake River Plain. In January 2024, Idaho Power transitioned from net metering to net billing for new customer-generators. The change is similar to California’s NEM 3.0 transition. Customers now pay the retail rate for all electricity drawn from the grid and receive a lower Export Credit Rate for electricity sent back.
The current ECR, published by Idaho Power Customer Generation FAQ (2026), is:
| Season | Time Period | Export Credit Rate |
|---|---|---|
| Summer on-peak | June 1 – Sept 30, 3 p.m. to 11 p.m. Monday-Saturday | 15.6836¢/kWh |
| Summer off-peak | June 1 – Sept 30, all other hours | 3.3920¢/kWh |
| Non-summer | Oct 1 – May 31, all hours | 2.9019¢/kWh |
These rates are fixed until Idaho Power proposes updates as part of an April 1, 2028 filing. The ECR is calculated using avoided cost principles: avoided energy cost, avoided generation capacity, avoided transmission and distribution capacity, avoided line losses, minus integration costs.
Systems installed before December 20, 2019, are legacy systems. They keep net metering until December 20, 2045. The legacy status attaches to the system and meter site, not the customer. A new buyer of a home with a legacy system inherits the legacy terms.
For new systems, the low non-summer ECR means exports outside the summer on-peak window have limited value. Self-consumption becomes critical. Homeowners who can shift load to midday or add a battery capture more value than those who simply export surplus.
Avista Utilities Net Metering
Avista serves northern Idaho, including Coeur d’Alene, Sandpoint, and the Idaho Panhandle. Avista still offers traditional net metering. Excess solar generation earns kilowatt-hour credits at the retail rate. Credits roll over month to month. Unused credits reset annually on March 31 and are granted to Avista with no payout.
Avista’s program has a 25 kW system size limit for residential customers. The annual reset means installers should size systems close to annual consumption rather than overbuilding. A system that produces 120% of annual usage effectively donates the surplus to the grid.
Avista residential rates in Idaho have risen sharply. A September 2025 increase raised typical residential bills by about 14.7%, and a further 5.3% increase was scheduled for September 2026, according to Inland Solar North Idaho analysis (2025). Rising rates improve solar economics even without new incentives.
Rocky Mountain Power
Rocky Mountain Power serves a small portion of eastern Idaho. The utility technically moved from net metering to net billing in November 2020 under Schedule 136. For residential systems under 25 kW, credits are still worth the full retail rate. There is currently no annual expiration of credits.
However, changes have been proposed. EnergySage reports that Rocky Mountain Power has proposed reducing compensation from the full retail rate to roughly 4 cents per kWh and adding a March 31 credit expiration. These changes require Idaho Public Utilities Commission approval. Homeowners in Rocky Mountain Power territory should verify the current tariff before signing a contract.
The takeaway is simple: Idaho solar value depends on geography. A home in Coeur d’Alene on Avista may see a 10-year payback. A similar home in Boise on Idaho Power may see 13 to 15 years.
Idaho Solar Costs and Payback in 2026
Solar installation costs in Idaho are close to the national benchmark. Multiple sources put the 2026 range between $2.56 and $3.45 per watt before incentives. ElectricChoice solar cost data (June 2026) lists Idaho at $2.56 per watt. PowerOutage.us Idaho solar data (June 2026) lists roughly $3.45 per watt.
For a typical 7 kW residential system:
| Metric | Low-Cost Scenario | Mid-Cost Scenario | High-Cost Scenario |
|---|---|---|---|
| Cost per watt | $2.56 | $3.00 | $3.45 |
| Gross system cost | $17,920 | $21,000 | $24,150 |
| Idaho deduction value over 4 years | ~$1,060 | ~$1,060 | ~$1,060 |
| Net cost after state deduction | $16,860 | $19,940 | $23,090 |
The federal residential tax credit is not included because it expired for homeowner-owned systems. Commercial, lease, and PPA structures may still capture Section 48E benefits.
Annual production for a 7 kW system in Idaho is roughly 9,500 to 11,000 kWh, depending on location, roof orientation, and shading. At Idaho Power’s retail rate of roughly 12 to 13 cents per kWh, a system that offsets 80% of a 900 kWh/month home saves about $1,100 to $1,300 per year. Under Avista net metering, savings may be higher if rates continue to rise. Under Idaho Power net billing, export credits add only a few hundred dollars per year unless the system is paired with storage or heavy self-consumption.
Typical payback periods in 2026:
- Avista territory with full retail net metering: 9 to 12 years
- Idaho Power territory with net billing and no battery: 12 to 16 years
- Rocky Mountain Power territory at current retail credits: 10 to 13 years
These periods are longer than the national average of roughly 8.7 years cited by Green Energy Calc payback guide (2026). The reason is Idaho’s low electricity rates. Solar hardware is affordable, but the value of each kilowatt-hour saved is low.
Financing Options: Cash, Loan, Lease, and PPA
The right financing structure depends on tax liability, ownership goals, and whether the homeowner wants to capture the Idaho state deduction.
Cash Purchase
Cash delivers the simplest math and the highest lifetime savings. The homeowner owns the system, claims the state deduction, and benefits from all future bill savings. There is no interest expense. Payback is typically 10 to 14 years, followed by 10 to 15 years of near-free electricity.
Solar Loan
A solar loan lets the homeowner own the system with little or no money down. The Idaho State Energy Loan Program is one option, with rates of 3-7% depending on term. Private solar loans are also available but often carry higher rates or dealer fees. The key question is whether loan interest and fees consume more value than the state deduction provides.
Solar Lease or Power Purchase Agreement
Leases and PPAs require no upfront payment. The third-party owner installs, maintains, and claims any available commercial tax benefits. The homeowner pays a fixed monthly amount or a per-kWh rate. These arrangements do not pass the Idaho Residential Alternative Energy Tax Deduction to the homeowner.
In 2026, leases and PPAs may still be attractive for homeowners with limited state tax liability or no desire to manage maintenance. Commercial third-party-owned systems may still access Section 48E, which can lower monthly payments. Homeowners who want the state deduction should purchase.
What Most Homeowners Get Wrong About Idaho Solar
Three mistakes recur in Idaho solar proposals.
First, many homeowners still assume the 30% federal tax credit applies. It does not for homeowner-owned systems placed in service after December 31, 2025. Any proposal that includes it overstates savings by thousands of dollars.
Second, homeowners in Idaho Power territory often oversize systems. Because exports earn only 2.9 to 15.7 cents per kWh, a system that produces 120% of annual usage wastes summer surplus. The optimal size is usually 85% to 100% of annual consumption, not 120%.
Third, many people confuse the Idaho deduction with a tax credit. A $20,000 deduction is not $20,000 in cash. At Idaho’s 5.3% top marginal rate, it is worth about $1,060 in reduced state tax. Installers should explain this clearly to avoid disappointed customers at tax time.
Commercial and Agricultural Solar in Idaho
Commercial, industrial, and agricultural solar projects in Idaho face the same low electricity rates but have access to different federal tools. Section 48E, the Clean Electricity Investment Tax Credit, remains active for eligible projects.
To qualify for the full 30% base credit, a project must begin construction by July 4, 2026, or be placed in service by December 31, 2027. Projects over 1 MW AC must meet prevailing wage and apprenticeship requirements to receive the full base rate. Bonus adders for energy communities and domestic content can increase the credit further.
Rural small businesses and agricultural producers can also apply for the USDA Rural Energy for America Program. REAP provides grants up to 50% of eligible project costs and loan guarantees up to 75% of eligible costs. This is one of the stronger federal supports for Idaho agriculture and rural commercial solar.
For installers modeling commercial projects, SurgePV’s generation and financial tool can stack Section 48E, REAP, depreciation, and utility rate structures in one workflow. Accurate modeling matters because commercial payback can range from 6 to 12 years depending on the stack.
How to Apply for Idaho Solar Incentives
Most incentives are claimed after installation rather than at the point of sale. The process is straightforward but requires documentation.
- Choose ownership structure. Decide whether to purchase with cash, finance with a loan, or use a lease or PPA. Only purchasers can claim the state deduction.
- Select a qualified installer. Verify licensing, insurance, and experience with your utility’s interconnection process.
- Complete interconnection. Submit the utility application and pay any fees. Idaho Power charges a $100 application fee.
- Install and inspect. The system must pass local electrical inspection and utility inspection before permission to operate.
- Claim the state deduction. File Idaho Schedule 39R Section B with your state tax return. Keep all receipts and contracts.
- Register for excess credit transfers if applicable. Idaho Power customers with multiple meters can request an annual credit transfer between December 1 and January 31.
Frequently Asked Questions
What solar incentives are available in Idaho in 2026?
Idaho solar incentives in 2026 include the Residential Alternative Energy Tax Deduction, which allows homeowners to deduct 40% of system cost in year one and 20% in each of the next three years, up to $5,000 per year and $20,000 total. The Idaho State Energy Loan Program offers low-interest loans up to $30,000 for solar and other energy upgrades. Idaho does not offer a statewide sales tax exemption or property tax exemption for solar. Net metering and net billing rules vary by utility.
Does Idaho have a state solar tax credit?
Idaho does not have a refundable state solar tax credit. It has a state income tax deduction. The Residential Alternative Energy Tax Deduction reduces taxable income by up to $5,000 per year for four years, with a total cap of $20,000. The actual cash value depends on the homeowner’s marginal state income tax rate.
Is the federal solar tax credit still available in Idaho in 2026?
The 30% federal Residential Clean Energy Credit under Internal Revenue Code Section 25D expired for homeowner-owned systems placed in service after December 31, 2025. Commercial, lease, and power purchase agreement systems may still qualify under Section 48E if construction begins by July 4, 2026, or the system is placed in service by December 31, 2027.
How does net metering work in Idaho in 2026?
Idaho does not have a statewide net metering mandate. Each investor-owned utility sets its own tariff. Idaho Power moved to net billing in January 2024 and pays an Export Credit Rate that ranges from roughly 2.9 cents per kWh in non-summer months to 15.7 cents per kWh during summer on-peak hours. Avista Utilities still offers 1:1 net metering with an annual March 31 credit reset. Rocky Mountain Power residential customers currently receive full retail credits, but proposed changes could reduce compensation.
What is the Idaho Power Export Credit Rate in 2026?
Idaho Power’s 2026 Export Credit Rate pays 15.6836 cents per kWh for summer on-peak exports, 3.3920 cents per kWh for summer off-peak exports, and 2.9019 cents per kWh during the non-summer season. The rate is locked until Idaho Power files an update with the Idaho Public Utilities Commission by April 1, 2028. These rates apply to non-legacy systems under Schedule 6, 8, or 84.
Does Idaho offer a property tax exemption for solar panels?
No. Idaho does not offer a statewide property tax exemption for residential solar panels. The added value of a solar system may be reflected in the property assessment. Homeowners should confirm treatment with their county assessor. This is a notable gap compared with neighboring states such as Oregon and Washington.
What is the typical solar payback period in Idaho in 2026?
A typical residential solar system in Idaho pays back in 10 to 14 years in 2026, depending on utility territory, system size, financing, and how much solar generation is consumed on-site. Payback is shorter in Avista territory with full retail net metering and longer in Idaho Power territory under net billing. Low electricity rates are the main reason Idaho payback periods exceed the national average.
How do I apply for the Idaho Residential Alternative Energy Tax Deduction?
Homeowners claim the deduction on their Idaho state income tax return. Full-year residents complete Section B of Idaho Supplemental Schedule 39R and transfer the amount to Form 40. Part-year residents and non-residents use Form 39NR and Form 43. Keep all invoices, contracts, and proof of payment. The installer typically provides an itemized receipt showing equipment and labor costs.
Can I lease solar panels in Idaho and still get incentives?
Leases and power purchase agreements do not pass the Idaho Residential Alternative Energy Tax Deduction to the homeowner. The third-party owner claims any available commercial tax benefits and may reflect them as lower monthly payments. Homeowners who want the state deduction and loan options should purchase the system with cash or a loan.
What is the most common mistake when applying for Idaho solar incentives?
The most common mistake is oversizing a system in Idaho Power territory. Because exports are paid at the low Export Credit Rate rather than the retail rate, producing far more than the home consumes yields poor value. Another frequent error is assuming the federal residential tax credit still applies to homeowner-owned systems installed in 2026.
Next Steps for Idaho Solar Buyers and Installers
Idaho solar is not the highest-savings market in the country, but it can still make sense for the right homeowner. The keys are accurate utility modeling, correct incentive expectations, and right-sized systems.
Three concrete actions:
- Verify your utility territory before quoting. Idaho Power, Avista, and Rocky Mountain Power have materially different export compensation rules.
- Model payback using current Idaho Power ECR rates and realistic self-consumption assumptions. Do not assume full retail net metering unless the customer is on Avista or a legacy Idaho Power system.
- For commercial and agricultural projects, evaluate Section 48E and USDA REAP before ruling solar out. The federal stack can change project economics significantly.
Installers can model Idaho incentives, utility rates, and financing in one platform with SurgePV’s solar design software. It builds solar proposals fast. Check pricing or book a demo to see Idaho-specific payback and ROI calculations.
