Solar panels in Louisville, KY
Roofs in Louisville get about 1,413 hours of usable sunlight a year — less than 76% 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 Louisville → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical Louisville solar system costs
A 23-panel system (9.2 kW) is about right for an average Louisville home using 10,800 kWh a year. It would produce roughly 11,050 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 3,843 | $6,384 | $469 | 13.6 yrs |
| 12 panels | 4.8 kW | 5,765 | $9,576 | $703 | 13.6 yrs |
| 16 panels | 6.4 kW | 7,687 | $12,768 | $938 | 13.6 yrs |
| 20 panels | 8 kW | 9,608 | $15,960 | $1,172 | 13.6 yrs |
| 26 panels | 10.4 kW | 12,491 | $20,748 | $1,369 | 15.2 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 Louisville gets 1,413 sun hours
That figure comes from Google's analysis of real rooftops across Louisville — 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 Louisville reaches about 1,577 hours, roughly 12% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,413 hrs/yr |
|---|---|
| Unshaded roof | 1,577 hrs/yr |
| Electricity rate (Kentucky avg) | 12.2¢/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 | 2023 |
Nearby cities
See all of Kentucky → statewide sunlight, rates, incentives and every city we've measured.
Louisville solar questions
How many solar panels do I need in Louisville?
About 23 panels for an average home. Louisville roofs get 1,413 usable sun hours a year, so each 400W panel produces roughly 480 kWh annually.
Is solar worth it in Louisville?
At 12.2¢/kWh and 1,413 sun hours, a typical system pays for itself in about 13.8 years and returns roughly $14,776 over 25 years. That is slower than the national average, so compare quotes carefully.
How much do solar panels cost in Louisville?
A 9.2 kW system costs about $26,220 before incentives and $18,354 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 Kentucky 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.