Solar panels in Butte, MT
Roofs in Butte get about 1,595 hours of usable sunlight a year — more than 64% of the cities we've measured. Here's what that means in cost, savings and payback, using real rooftop data rather than a national average.
Check your specific roof in Butte → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical Butte solar system costs
A 20-panel system (8 kW) is about right for an average Butte home using 10,800 kWh a year. It would produce roughly 10,846 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 4,338 | $6,384 | $525 | 12.2 yrs |
| 12 panels | 4.8 kW | 6,508 | $9,576 | $787 | 12.2 yrs |
| 16 panels | 6.4 kW | 8,677 | $12,768 | $1,050 | 12.2 yrs |
| 20 panels | 8 kW | 10,846 | $15,960 | $1,308 | 12.2 yrs |
| 26 panels | 10.4 kW | 14,100 | $20,748 | $1,407 | 14.8 yrs |
How we worked this out for Butte
Every number on this page comes from these seven steps. Nothing is a national average — the sunlight figure is measured from Butte rooftops.
| # | Step | Result |
|---|---|---|
| 1 | What one panel makes here 400W ÷ 1000 × 1,595 sun hrs × 0.85 system losses |
542 kWh/yr |
| 2 | Panels needed to cover typical usage 10,800 kWh ÷ 542 kWh per panel |
20 panels |
| 3 | System size 20 panels × 400W |
8.00 kW |
| 4 | Annual production 8.00 kW × 1,595 hrs × 0.85 |
10,846 kWh/yr |
| 5 | Installed cost 8,000 W × $2.85 per watt, then −30% federal credit |
$15,960 |
| 6 | Annual saving 3,780 kWh used as generated × 12.1¢ + 7,066 kWh exported × 12.1¢ |
$1,308/yr |
| 7 | Payback $15,960 ÷ $1,308 per year |
12.2 years |
Step 6 matters more than it looks. Only 35% of what a system this size produces in Butte is used the moment it is generated; the other 7,066 kWh is exported and credited one-for-one under net metering. Because exports here are credited at or near retail, that split changes the payback very little — 12.2 years against the 12.2 we show. In places where exports pay a fraction of retail the same split moves payback by years, which is why we model it explicitly rather than assuming.
Assumptions: 400W panels, 15% system losses (inverter, wiring, heat, soiling), $2.85/W installed, 10,800 kWh typical annual household use, 12.1¢/kWh electricity. Change any of those and every figure above moves — which is exactly why a single national "solar costs X" number is misleading.
Notice that payback barely improves as systems get bigger, and eventually gets worse. That's because you can only save money on electricity you were going to buy anyway. Once a system covers your usage, extra panels mostly generate exports at a much lower rate.
Why Butte gets 1,595 sun hours
That figure comes from Google's analysis of real rooftops across Butte — it already accounts for shading from trees, chimneys and neighbouring buildings, which is why it's lower than the raw "hours of daylight" figures you'll see elsewhere. An unusually open, unshaded roof in Butte reaches about 1,648 hours, roughly 3% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,595 hrs/yr |
|---|---|
| Unshaded roof | 1,648 hrs/yr |
| Electricity rate (Montana avg) | 12.1¢/kWh |
| Installed cost assumed | $2.85/W |
| Panel size assumed | 400 W |
| Federal tax credit | 30% |
| Typical household usage | 10,800 kWh/yr |
| Power used as generated | 35% |
| Paid for exported power | full retail (net metering) |
| Rooftops sampled here | 5 |
| Google imagery from | 2014 |
When Butte actually produces
Annual totals hide the thing that catches people out: 39% of Butte's yearly sunlight arrives in May–July, and just 11% across November–January.
| Month | Sun hrs | Share of year |
|---|---|---|
| Jan | 59 | |
| Feb | 87 | |
| Mar | 126 | |
| Apr | 168 | |
| May | 200 | |
| Jun | 213 | |
| Jul | 206 | |
| Aug | 180 | |
| Sep | 141 | |
| Oct | 98 | |
| Nov | 65 | |
| Dec | 52 |
That is a severe seasonal swing — Butte produces roughly 4.1× as much in Jun as in Dec. A system sized to cover your annual usage will overproduce badly in summer and fall well short in winter, so how your utility credits exported power matters more here than in most places.
The annual total is measured from Google's rooftop imagery. Its split across months is calculated from solar geometry at Butte's latitude, not separately measured, so treat the monthly figures as the shape of a typical year rather than a forecast.
How Butte compares to the other 788 cities
| Measure | Butte | Rank of 788 |
|---|---|---|
| Usable sunlight | 1,595 hrs | 285th |
| Sunlight lost to shade | 3% | 615th most |
| Median roof size | 201 m² | 364th largest |
| Electricity rate | 12.1¢ | 721st highest |
| Payback | 12.2 yrs | 566th fastest |
| Grid carbon | 696 kg/MWh | 261st dirtiest |
What actually stands out about Butte:
- Sunnier than the rest of Montana. Butte roofs get 7% more usable sunlight than the typical Montana city we've measured — statewide averages will understate what you can expect here.
- Cheap electricity is the headwind. Montana power costs about 12.1¢/kWh. Low rates are good news generally, but they lengthen solar payback — there is simply less bill to displace.
- Older imagery. Google's aerial capture of Butte dates from 2014. Tree growth and new construction since then are not reflected.
Cities with almost the same sunlight
These are the closest matches to Butte's 1,595 usable sun hours from other states and provinces. Same sunlight, different electricity prices — which is usually what decides whether solar is worth it.
| City | Sun hrs | Rate | Payback |
|---|---|---|---|
| Texarkana, AR | 1,595 | 12.4¢ | 11.9 yrs |
| Longview, TX | 1,595 | 15.1¢ | 9.8 yrs |
| Boise, ID | 1,594 | 11.2¢ | 13.2 yrs |
| Albany, GA | 1,594 | 14.1¢ | 10.5 yrs |
Nearby cities
See all of Montana → statewide sunlight, rates, incentives and every city we've measured.
Butte solar questions
How many solar panels do I need in Butte?
About 20 panels for an average home using 10,800 kWh a year. Butte roofs get 1,595 usable sun hours, so each 400W panel produces roughly 542 kWh annually. A typical Butte roof fits about 50 panels, so roof space is unlikely to be your limit.
Is solar worth it in Butte?
At 12.1¢/kWh and 1,595 sun hours, a typical system pays for itself in about 12.2 years and returns roughly $16,745 over a 25-year panel life. That is slower than average, so compare several quotes before committing. Exported power earns full retail credit here.
How much do solar panels cost in Butte?
A 8 kW system costs about $22,800 before incentives and $15,960 after the 30% federal tax credit. That works out near $2.85 per watt installed. Roof pitch, shading, electrical panel upgrades and equipment choice move the price most, which is why quotes for the same house can differ by thousands.
Worth reading before you buy
Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average Montana electricity rates. Not a quote and not financial advice. Your roof, usage, utility plan and local incentives will change these numbers — get real quotes before buying.