Solar panels in Knoxville, TN
Roofs in Knoxville get about 1,514 hours of usable sunlight a year — more than 50% 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 Knoxville → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical Knoxville solar system costs
A 21-panel system (8.4 kW) is about right for an average Knoxville home using 10,800 kWh a year. It would produce roughly 10,810 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 4,118 | $6,384 | $498 | 12.8 yrs |
| 12 panels | 4.8 kW | 6,177 | $9,576 | $747 | 12.8 yrs |
| 16 panels | 6.4 kW | 8,236 | $12,768 | $997 | 12.8 yrs |
| 20 panels | 8 kW | 10,295 | $15,960 | $1,246 | 12.8 yrs |
| 26 panels | 10.4 kW | 13,384 | $20,748 | $1,385 | 15 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 Knoxville gets 1,514 sun hours
That figure comes from Google's analysis of real rooftops across Knoxville — 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 Knoxville reaches about 1,652 hours, roughly 9% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,514 hrs/yr |
|---|---|
| Unshaded roof | 1,652 hrs/yr |
| Electricity rate (Tennessee 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 | 15 |
| Google imagery from | 2023 |
Nearby cities
See all of Tennessee → statewide sunlight, rates, incentives and every city we've measured.
Knoxville solar questions
How many solar panels do I need in Knoxville?
About 21 panels for an average home. Knoxville roofs get 1,514 usable sun hours a year, so each 400W panel produces roughly 515 kWh annually.
Is solar worth it in Knoxville?
At 12.1¢/kWh and 1,514 sun hours, a typical system pays for itself in about 12.8 years and returns roughly $15,920 over 25 years. That is slower than the national average, so compare quotes carefully.
How much do solar panels cost in Knoxville?
A 8.4 kW system costs about $23,940 before incentives and $16,758 after the 30% federal tax credit. Prices vary by installer, roof complexity and equipment.
Worth reading before you buy
Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average Tennessee 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.