Wind Turbine Payback in Hardin County, TN
Wind turbine payback in Hardin County
No. The turbine wears out before it pays for itself.
At 30 m, the height a home turbine tower usually reaches, the wind in Hardin County, TN averages 3.44 m/s (7.7 mph). A 10 kW turbine there would make about 4,094 kWh a year, worth $565 at TN's 13.8¢/kWh. Against an installed cost of about $100,000, that is a payback of over 100 years, and the turbine is built to last about 20.
What to do in Hardin County
A home turbine is not worth buying for savings in Hardin County unless your spot is far windier than the county average, 8.4 m/s at the hub against 3.44 m/s here. Per kW, solar panels would make about 1,279 kWh a year here against the turbine's 409, so get a solar quote first.
What would have to change
- Power would have to cost 122¢/kWh, 8.8 times what TN pays now.
- Or the average wind at the hub would have to be 8.4 m/s instead of 3.44. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of TN
Hardin County is the 2,573rd windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in TN is Lake County at 5.54 m/s, payback 44 years.
Month by month in Hardin County
March is the strongest month here, at 4.08 m/s and about 595 kWh. July is the weakest, 2.54 m/s and 121 kWh, so the best month makes 4.9 times the worst. November to March brings in 57% of the year's output in Hardin County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.91 m/s | 522 kWh | $72 |
| February | 4.06 m/s | 528 kWh | $73 |
| March | 4.08 m/s | 595 kWh | $82 |
| April | 4.04 m/s | 559 kWh | $77 |
| May | 3.36 m/s | 323 kWh | $45 |
| June | 2.81 m/s | 171 kWh | $24 |
| July | 2.54 m/s | 121 kWh | $17 |
| August | 2.62 m/s | 136 kWh | $19 |
| September | 3.04 m/s | 223 kWh | $31 |
| October | 3.41 m/s | 338 kWh | $47 |
| November | 3.69 m/s | 420 kWh | $58 |
| December | 3.75 m/s | 458 kWh | $63 |
What a taller tower would buy
Measured at 10 m the wind in Hardin County averages 2.19 m/s; at 50 m it is 4.25 m/s. That gives a shear exponent of 0.412, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,353 to 7,897 kWh a year, 236% more, before counting the extra cost of the taller tower. Why tower height decides it explains the shear behind these numbers.
| Hub height | Average wind | Output | Payback |
|---|---|---|---|
| 20 m | 2.91 m/s | 2,353 kWh | over 100 years |
| 30 m | 3.44 m/s | 4,107 kWh | over 100 years |
| 40 m | 3.88 m/s | 5,974 kWh | over 100 years |
| 50 m | 4.25 m/s | 7,897 kWh | 92 years |
Counties around Hardin County
3 of the 6 closest counties are windier at turbine height; the windiest, Chester County, averages 4.34 m/s.
- Wayne County, TN: 3.44 m/s, 4,094 kWh, payback over 100 years (21 mi)
- McNairy County, TN: 3.47 m/s, 4,211 kWh, payback over 100 years (21 mi)
- Decatur County, TN: 3.28 m/s, 3,506 kWh, payback over 100 years (28 mi)
- Chester County, TN: 4.34 m/s, 8,403 kWh, payback 86 years (28 mi)
- Alcorn County, MS: 3.47 m/s, 4,211 kWh, payback over 100 years (31 mi)
- Tishomingo County, MS: 3.31 m/s, 3,612 kWh, payback over 100 years (32 mi)
Sun versus wind in Hardin County
Hardin County gets 4.38 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,279 kWh a year; one kW of the turbine above makes 409. Kilowatt for kilowatt, panels make 3.1 times as much here as the turbine. Panel output assumes an 80% system performance ratio. Wind or solar runs the same comparison for every county.
How this is worked out
Wind is NASA's Power climate record, the 2001-2025 average at 10 m and 50 m for the county's centre, carried to 30 m with this county's own measured wind shear and spread into hours with a Rayleigh distribution. The turbine is a generic 10 kW, 7 m rotor machine with 10% losses. Cost is $10,000 per kW installed with no tax credit, because the federal one ended in 2025. One county-centre number cannot see your hilltop or your tree line, so treat it as the starting point for a site survey, not a substitute. The full method and its weak spots are in how the numbers are made.