Wind Turbine Payback in Hopkins County, KY
Wind turbine payback in Hopkins 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 Hopkins County, KY averages 4.88 m/s (10.9 mph). A 10 kW turbine there would make about 11,734 kWh a year, worth $1,666 at KY's 14.2¢/kWh. Against an installed cost of about $100,000, that is a payback of 60 years, and the turbine is built to last about 20.
What to do in Hopkins County
A home turbine is not worth buying for savings in Hopkins County unless your spot is far windier than the county average, 8.2 m/s at the hub against 4.88 m/s here. Per kW, solar panels would make about 1,223 kWh a year here against the turbine's 1,173, so get a solar quote first.
What would have to change
- Power would have to cost 43¢/kWh, 3.0 times what KY pays now.
- Or the average wind at the hub would have to be 8.2 m/s instead of 4.88. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of KY
Hopkins County is the 1,517th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in KY is Fulton County at 5.54 m/s, payback 43 years.
Month by month in Hopkins County
March is the strongest month here, at 5.75 m/s and about 1,518 kWh. July is the weakest, 3.59 m/s and 399 kWh, so the best month makes 3.8 times the worst. November to March brings in 56% of the year's output in Hopkins County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.66 m/s | 1,459 kWh | $207 |
| February | 5.65 m/s | 1,313 kWh | $186 |
| March | 5.75 m/s | 1,518 kWh | $216 |
| April | 5.81 m/s | 1,506 kWh | $214 |
| May | 4.84 m/s | 972 kWh | $138 |
| June | 4.07 m/s | 568 kWh | $81 |
| July | 3.59 m/s | 399 kWh | $57 |
| August | 3.61 m/s | 405 kWh | $58 |
| September | 4.06 m/s | 564 kWh | $80 |
| October | 4.90 m/s | 1,005 kWh | $143 |
| November | 5.32 m/s | 1,212 kWh | $172 |
| December | 5.39 m/s | 1,294 kWh | $184 |
What a taller tower would buy
Measured at 10 m the wind in Hopkins County averages 3.57 m/s; at 50 m it is 5.64 m/s. That gives a shear exponent of 0.284, typical of ordinary open country. Going from 20 m to 50 m takes output from 8,447 to 17,053 kWh a year, 102% 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 | 4.35 m/s | 8,447 kWh | 83 years |
| 30 m | 4.88 m/s | 11,723 kWh | 60 years |
| 40 m | 5.29 m/s | 14,564 kWh | 48 years |
| 50 m | 5.64 m/s | 17,053 kWh | 41 years |
Counties around Hopkins County
2 of the 6 closest counties are windier at turbine height; the windiest, Crittenden County, averages 5.26 m/s.
- Webster County, KY: 4.88 m/s, 11,734 kWh, payback 60 years (16 mi)
- Caldwell County, KY: 4.94 m/s, 12,132 kWh, payback 58 years (21 mi)
- McLean County, KY: 4.88 m/s, 11,734 kWh, payback 60 years (21 mi)
- Muhlenberg County, KY: 4.38 m/s, 8,632 kWh, payback 82 years (23 mi)
- Christian County, KY: 4.46 m/s, 9,100 kWh, payback 77 years (29 mi)
- Crittenden County, KY: 5.26 m/s, 14,327 kWh, payback 49 years (31 mi)
Sun versus wind in Hopkins County
Hopkins County gets 4.19 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,223 kWh a year; one kW of the turbine above makes 1,173. Kilowatt for kilowatt, panels make 1.0 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.