Peak sun hours in Tennessee
Tennessee averages 4.4 peak sun hours a day across the year, 25th of the 50 states. At that figure a 400-watt panel produces about 1.36 kWh a day after real-world losses, and covering the 900 kWh average US bill takes about 22 panels. Nashville, the state's biggest city, sits at 4.5 hours, close to the statewide figure, though microclimates and elevation still move the local number.
solid mid-pack sun: 4.4 of a possible ~6.5 hours
Panel counts for Tennessee bills
Computed at Tennessee's 4.4 hours with 400W panels and the 0.77 derate; the US-average column shows what the same bill takes at 4.5 hours, so you can see what your state's sun is worth in hardware.
| Monthly usage | Tennessee | System size | US average |
|---|---|---|---|
| 500 kWh/mo | 13 panels | 5.2 kW | 12 panels |
| 750 kWh/mo | 19 panels | 7.6 kW | 18 panels |
| 900 kWh/mo | 22 panels | 8.8 kW | 22 panels |
| 1,000 kWh/mo | 25 panels | 10 kW | 24 panels |
| 1,500 kWh/mo | 37 panels | 14.8 kW | 36 panels |
| 2,000 kWh/mo | 49 panels | 19.6 kW | 48 panels |
What 4.4 hours means in practice
Tennessee is mid-pack American sun: 25th of 50 at 4.4 peak sun hours, within 2% of the national average. The 900 kWh average bill lands at 22 panels, same as the US-average count. At this tier the resource neither makes nor breaks the project. Electricity rates and net-metering terms decide whether solar pencils here, and those change by utility, not by state.
For a location-exact figure, run your address through NREL's free PVWatts; it uses measured weather for your grid cell and will also model roof tilt and direction, which statewide numbers cannot. Then compare its annual kWh against a quote's promise before you sign anything.
Questions people ask
How many solar panels do I need in Tennessee?
About 22 400-watt panels (8.8 kW) for the 900 kWh a month an average US home uses, at Tennessee's 4.4 peak sun hours. Your bill is the variable that matters: the table on this page covers 500 to 2,000 kWh, and the calculator takes any figure.
Is 4.4 peak sun hours good for solar?
It is solidly workable. Tennessee sits near the national average of 4.5 hours, so panel counts here match the US-typical figures, and project economics turn on your utility's rates and net-metering terms rather than on the sun.
Do peak sun hours change with the seasons in Tennessee?
Yes, everywhere: the figure on this page is the annual average of a curve that peaks in June and bottoms out in December. In Tennessee the swing is meaningful but manageable; summer typically runs half again the annual figure and December two-thirds or less of it. Grid-tied homes bank summer overproduction as credit; off-grid designs must size for the trough, not the average.