Solar panels in Lewiston, ID
Roofs in Lewiston get about 1,485 hours of usable sunlight a year — less than 61% 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 Lewiston → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical Lewiston solar system costs
A 22-panel system (8.8 kW) is about right for an average Lewiston home using 10,800 kWh a year. It would produce roughly 11,108 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 4,039 | $6,384 | $452 | 14.1 yrs |
| 12 panels | 4.8 kW | 6,059 | $9,576 | $679 | 14.1 yrs |
| 16 panels | 6.4 kW | 8,078 | $12,768 | $905 | 14.1 yrs |
| 20 panels | 8 kW | 10,098 | $15,960 | $1,131 | 14.1 yrs |
| 26 panels | 10.4 kW | 13,127 | $20,748 | $1,275 | 16.3 yrs |
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 Lewiston gets 1,485 sun hours
That figure comes from Google's analysis of real rooftops across Lewiston — 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 Lewiston reaches about 1,529 hours, roughly 3% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,485 hrs/yr |
|---|---|
| Unshaded roof | 1,529 hrs/yr |
| Electricity rate (Idaho avg) | 11.2¢/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 | 34% |
| Paid for exported power | full retail (net metering) |
| Rooftops sampled here | 7 |
| Google imagery from | 2019 |
When Lewiston actually produces
Annual totals hide the thing that catches people out: 39% of Lewiston's yearly sunlight arrives in May–July, and just 11% across November–January.
| Month | Sun hrs | Share of year |
|---|---|---|
| Jan | 54 | |
| Feb | 80 | |
| Mar | 117 | |
| Apr | 157 | |
| May | 187 | |
| Jun | 200 | |
| Jul | 193 | |
| Aug | 168 | |
| Sep | 131 | |
| Oct | 91 | |
| Nov | 60 | |
| Dec | 47 |
That is a severe seasonal swing — Lewiston produces roughly 4.2× 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 Lewiston's latitude, not separately measured, so treat the monthly figures as the shape of a typical year rather than a forecast.
How Lewiston compares to the other 673 cities
| Measure | Lewiston | Rank of 673 |
|---|---|---|
| Usable sunlight | 1,485 hrs | 410th |
| Sunlight lost to shade | 3% | 559th most |
| Median roof size | 238 m² | 248th largest |
| Electricity rate | 11.2¢ | 651st highest |
| Payback | 14.4 yrs | 591st fastest |
| Grid carbon | 696 kg/MWh | 263rd dirtiest |
What actually stands out about Lewiston:
- Dimmer than the rest of Idaho. Lewiston roofs get 10% less usable sunlight than the typical Idaho city we've measured — statewide averages will overstate what you can expect here.
- Cheap electricity is the headwind. Idaho power costs about 11.2¢/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 Lewiston dates from 2019. Tree growth and new construction since then are not reflected.
Cities with almost the same sunlight
These are the closest matches to Lewiston's 1,485 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 |
|---|---|---|---|
| Richmond, IN | 1,485 | 15.3¢ | 10.5 yrs |
| Asheville, NC | 1,486 | 13.2¢ | 12.2 yrs |
| Woodbury, MN | 1,483 | 14.8¢ | 10.9 yrs |
| Edison, NJ | 1,483 | 19.4¢ | 8.3 yrs |
Nearby cities
See all of Idaho → statewide sunlight, rates, incentives and every city we've measured.
Lewiston solar questions
How many solar panels do I need in Lewiston?
About 22 panels for an average home using 10,800 kWh a year. Lewiston roofs get 1,485 usable sun hours, so each 400W panel produces roughly 505 kWh annually. A typical Lewiston roof fits about 86 panels, so roof space is unlikely to be your limit.
Is solar worth it in Lewiston?
At 11.2¢/kWh and 1,485 sun hours, a typical system pays for itself in about 14.4 years and returns roughly $12,899 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 Lewiston?
A 8.8 kW system costs about $25,080 before incentives and $17,556 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 Idaho 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.