Solar panels in Rock Springs, WY
Roofs in Rock Springs get about 1,844 hours of usable sunlight a year — more than 87% 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 Rock Springs → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical Rock Springs solar system costs
A 18-panel system (7.2 kW) is about right for an average Rock Springs home using 10,800 kWh a year. It would produce roughly 11,285 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 5,016 | $6,384 | $607 | 10.5 yrs |
| 12 panels | 4.8 kW | 7,524 | $9,576 | $910 | 10.5 yrs |
| 16 panels | 6.4 kW | 10,031 | $12,768 | $1,214 | 10.5 yrs |
| 20 panels | 8 kW | 12,539 | $15,960 | $1,359 | 11.7 yrs |
| 26 panels | 10.4 kW | 16,301 | $20,748 | $1,473 | 14.1 yrs |
How we worked this out for Rock Springs
Every number on this page comes from these seven steps. Nothing is a national average — the sunlight figure is measured from Rock Springs rooftops.
| # | Step | Result |
|---|---|---|
| 1 | What one panel makes here 400W ÷ 1000 × 1,844 sun hrs × 0.85 system losses |
627 kWh/yr |
| 2 | Panels needed to cover typical usage 10,800 kWh ÷ 627 kWh per panel |
18 panels |
| 3 | System size 18 panels × 400W |
7.20 kW |
| 4 | Annual production 7.20 kW × 1,844 hrs × 0.85 |
11,285 kWh/yr |
| 5 | Installed cost 7,200 W × $2.85 per watt, then −30% federal credit |
$14,364 |
| 6 | Annual saving 3,780 kWh used as generated × 12.1¢ + 7,505 kWh exported × 12.1¢ |
$1,321/yr |
| 7 | Payback $14,364 ÷ $1,321 per year |
10.9 years |
Step 6 matters more than it looks. Only 33% of what a system this size produces in Rock Springs is used the moment it is generated; the other 7,505 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 — 10.5 years against the 10.9 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 Rock Springs gets 1,844 sun hours
That figure comes from Google's analysis of real rooftops across Rock Springs — 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 Rock Springs reaches about 1,910 hours, roughly 4% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,844 hrs/yr |
|---|---|
| Unshaded roof | 1,910 hrs/yr |
| Electricity rate (Wyoming 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 | 33% |
| Paid for exported power | full retail (net metering) |
| Rooftops sampled here | 4 |
| Google imagery from | 2015 |
When Rock Springs actually produces
Annual totals hide the thing that catches people out: 37% of Rock Springs's yearly sunlight arrives in May–July, and just 13% across November–January.
| Month | Sun hrs | Share of year |
|---|---|---|
| Jan | 79 | |
| Feb | 109 | |
| Mar | 148 | |
| Apr | 190 | |
| May | 220 | |
| Jun | 232 | |
| Jul | 225 | |
| Aug | 201 | |
| Sep | 163 | |
| Oct | 120 | |
| Nov | 86 | |
| Dec | 71 |
Rock Springs produces about 3.3× as much in Jun as in Dec — a normal mid-latitude swing. Expect real winter shortfall and summer surplus rather than steady year-round output.
The annual total is measured from Google's rooftop imagery. Its split across months is calculated from solar geometry at Rock Springs's latitude, not separately measured, so treat the monthly figures as the shape of a typical year rather than a forecast.
How Rock Springs compares to the other 788 cities
| Measure | Rock Springs | Rank of 788 |
|---|---|---|
| Usable sunlight | 1,844 hrs | 106th |
| Sunlight lost to shade | 3% | 582nd most |
| Median roof size | 119 m² | 658th largest |
| Electricity rate | 12.1¢ | 717th highest |
| Payback | 10.9 yrs | 416th fastest |
| Grid carbon | 696 kg/MWh | 258th dirtiest |
What actually stands out about Rock Springs:
- Sunnier than the rest of Wyoming. Rock Springs roofs get 9% more usable sunlight than the typical Wyoming city we've measured — statewide averages will understate what you can expect here.
- Cheap electricity is the headwind. Wyoming 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 Rock Springs dates from 2015. Tree growth and new construction since then are not reflected.
Cities with almost the same sunlight
These are the closest matches to Rock Springs's 1,844 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 |
|---|---|---|---|
| Greeley, CO | 1,843 | 14.8¢ | 8.9 yrs |
| Garden City, KS | 1,847 | 14.1¢ | 9.3 yrs |
| West Covina, CA | 1,848 | 31.2¢ | 8.7 yrs |
| Klamath Falls, OR | 1,839 | 12.4¢ | 10.6 yrs |
Nearby cities
See all of Wyoming → statewide sunlight, rates, incentives and every city we've measured.
Rock Springs solar questions
How many solar panels do I need in Rock Springs?
About 18 panels for an average home using 10,800 kWh a year. Rock Springs roofs get 1,844 usable sun hours, so each 400W panel produces roughly 627 kWh annually. A typical Rock Springs roof fits about 31 panels, so check your usable roof area before assuming that many will fit.
Is solar worth it in Rock Springs?
At 12.1¢/kWh and 1,844 sun hours, a typical system pays for itself in about 10.9 years and returns roughly $18,673 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 Rock Springs?
A 7.2 kW system costs about $20,520 before incentives and $14,364 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 Wyoming 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.