Solar in Great Falls, MT: 2026 Cost, Savings & Payback
Calculate 2026 solar panel cost, payback, and 25-year bill savings in Great Falls, Montana. Based on 4.6 peak sun hours/day, 11.6¢/kWh average electricity rate, NorthWestern Energy utility context, and current IRS guidance for the ended federal residential clean energy credit.
Solar in Great Falls, MT: quick answer
A typical 6kW solar system in Great Falls costs about $17,220 before local or state incentives. For 2026 installs, the federal residential clean energy credit is modeled as $0, so the estimated cost remains about $17,220 before any local incentive. It produces about 8,059 kWh per year from 4.6 peak sun hours/day, saves about $937 per year, and reaches payback in about 18.4 years.
2026 6kW Cost
$17,220
Monthly Savings
$78
Production / kW
1,343 kWh
Panel Count
~15
4.6
Peak Sun Hours/Day
11.6¢
Avg Rate (¢/kWh)
18.4 yr
Payback Period
$32k
25-Year Savings
Great Falls Solar Overview
Calculate Your Great Falls Solar Savings
Great Falls average: $98/mo
South-facing roofs produce the most energy
Add $8,000-$12,000 for whole-home battery backup
Annual Production
kWh/year
Annual Savings
per year
Net System Cost
after 2026 federal credit
Payback Period
break-even time
Bill Offset and Export Assumptions
Current Annual Bill
$1,176
Estimated Usage
10,112 kWh
Bill Offset
80%
Used On Site
100%
Exported production is discounted in this planning model instead of being treated as a guaranteed one-for-one bill credit. For Great Falls, verify the current NorthWestern Energy export-credit method and any fixed monthly charges before relying on the payback number.
25-Year Total Savings
$32,006
Monthly Savings
$78
2026 Federal Credit
$0
Cumulative Savings vs System Cost
Cost Breakdown
| Item | Great Falls | National Avg |
|---|---|---|
| Gross System Cost (6kW) | $17,220 | $17,100 |
| 2026 Federal Residential Credit | -$0 | $0 |
| Net System Cost | $17,220 | $17,100 |
| Cost Per Watt | $2.87/W | $2.85/W |
Solar Potential in Great Falls
Sun Hours vs National Average
Great Falls gets 2% more sun than the national average.
Climate Advantages
- 170 sunny days per year
- Average temperature: 47.7°F — cooler temps actually improve panel efficiency
- Average roof size: 1,513 sq ft — enough for a 84-panel system
Great Falls Solar Incentives & Programs
Federal Investment Tax Credit (ITC)
For 2026 planning, JouleIO does not subtract a federal residential clean energy credit. The IRS says the Residential Clean Energy Credit was 30% for eligible property installed from 2022 through December 31, 2025, and is not available for property placed in service after December 31, 2025.
Source: IRS Residential Clean Energy Credit and IRS One Big Beautiful Bill provisions.
Montana State Incentives
Montana property tax exemption for solar; net metering at retail rate
Net Metering — NorthWestern Energy
NorthWestern Energy offers net metering in Great Falls. Earn credits for excess solar energy sent to the grid, reducing your electric bill further.
Environmental Impact in Great Falls
3.4
Tons CO2 Offset/Year
55
Equivalent Trees Planted
0.8
Homes Worth of Energy
Based on 8,059 kWh annual production with a 6kW system. EPA average: 0.417 metric tons CO2 per MWh, 10,632 kWh per US home.
Solar Energy in Great Falls, Montana
Great Falls, Montana receives an average of 4.6 peak sun hours per day, providing excellent conditions for residential solar installations. With electricity rates averaging 11.6¢ per kWh from NorthWestern Energy, below the national average, but with rates rising 2-3% annually, the long-term savings are still meaningful.
A typical 6kW solar system in Great Falls produces approximately 8,059 kWh per year, saving homeowners an estimated $937 annually. The system pays for itself in about 18.4 years, after which you enjoy essentially free electricity for the remaining 7+ years of the system's warranty life.
Great Falls has a solar penetration rate of 3% — indicating early-stage solar adoption with tremendous growth potential as prices continue to fall. The cost of living index of 102 (national average: 100) is near the national average.
Other Cities in Montana
Methodology & Solar Data Sources for Great Falls
How we calculate Great Falls solar potential and savings: Solar production estimates use NREL's PVWatts calculator methodology, applied to Great Falls's specific solar irradiance (peak sun hours), tilt angle, and azimuth. Cost figures combine NREL's Annual Technology Baseline for system pricing, ENERGY STAR's database for residential PV averages, and EIA Form 861 utility rate data for Montana.
- Solar irradiance for Great Falls: based on NREL National Solar Radiation Database (NSRDB) — 30-year average peak sun hours per day.
- System sizing assumes residential rooftop installation with standard 350-400W panels, calibrated to typical Great Falls household electricity usage.
- Federal tax credit: modeled as 0% for 2026 residential installations because IRS guidance says the Residential Clean Energy Credit is not available for property placed in service after December 31, 2025.
- Net metering assumes 1:1 retail-rate compensation typical in Montana (verify with local utility — some have shifted to net billing or avoided-cost rates).
- System lifetime standard 25 years with annual degradation of 0.5%/year per industry warranty norms.
Authoritative US solar data sources:
- NREL PVWatts Calculator — official US solar production estimator
- NREL National Solar Radiation Database — 30-year solar irradiance data
- IRS Residential Clean Energy Credit — 2026 federal residential credit status
- IRS One Big Beautiful Bill provisions — clean energy credit expiration overview
- DSIRE — State Solar Incentives — searchable database for Montana
- EIA Electric Power Monthly — Montana utility rate data
- ENERGY STAR Solar — efficient solar product database
Solar Disclaimer: Solar savings vary based on roof orientation, shading, system quality, installer markup, financing terms, utility rate plan, and policy changes. Always get 3+ quotes from NABCEP-certified installers and review contracts carefully. Tax credit eligibility depends on tax liability — consult a tax professional.
Reviewed by Brazora Monk · Last updated 2026 · NREL irradiance data per NSRDB latest release
Frequently Asked Questions
How much do solar panels cost in Great Falls, MT?
The average cost of a 6kW solar panel system in Great Falls is approximately $17,220 before local or state incentives ($2.87/watt). For 2026 planning, this calculator does not subtract a federal residential clean energy credit because IRS guidance says the credit is not available for property placed in service after December 31, 2025. Montana property tax exemption for solar; net metering at retail rate
How many solar panels do I need in Great Falls, MT?
A typical 6kW residential solar system in Great Falls needs about 15 panels if each panel is rated near 400 watts. That system produces about 8,059 kWh per year in this estimate, or roughly 1,343 kWh per installed kW before shading, roof orientation, and inverter losses are customized.
How many peak sun hours does Great Falls get?
Great Falls, MT receives an average of 4.6 peak sun hours per day and approximately 170 sunny days per year. This is near the national average, providing good conditions for residential solar panels.
What is the solar payback period in Great Falls?
The average solar payback period in Great Falls is approximately 18.4 years for a 6kW cash-price estimate before local or state incentives. After payback, your solar panels generate essentially free electricity for the remaining warranty life. Over 25 years, bill savings can reach about $32,006 before subtracting installation cost.
Does Great Falls have net metering?
Yes, Great Falls has access to net metering through NorthWestern Energy. This allows you to earn credits for excess solar energy sent to the grid, but the final savings depend on the current utility tariff and fixed monthly charges.
Is solar worth it in Great Falls, MT in 2026?
Solar may still be worthwhile in Great Falls, especially for homeowners with high usage or strong local incentives, but the 18.4-year payback means quote comparison matters. For 2026 installs, JouleIO does not assume a federal residential credit; local incentives and net metering are the main financial drivers.