Wind Turbine Payback in Copiah County, MS
Wind turbine payback in Copiah 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 Copiah County, MS averages 3.21 m/s (7.2 mph). A 10 kW turbine there would make about 3,265 kWh a year, worth $492 at MS's 15.06¢/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 Copiah County
A home turbine is not worth buying for savings in Copiah County unless your spot is far windier than the county average, 7.9 m/s at the hub against 3.21 m/s here. Per kW, solar panels would make about 1,346 kWh a year here against the turbine's 327, so get a solar quote first.
What would have to change
- Power would have to cost 153¢/kWh, 10.2 times what MS pays now.
- Or the average wind at the hub would have to be 7.9 m/s instead of 3.21. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MS
Copiah County is the 2,874th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in MS is DeSoto County at 5.13 m/s, payback 50 years.
Month by month in Copiah County
March is the strongest month here, at 3.67 m/s and about 428 kWh. July is the weakest, 2.48 m/s and 111 kWh, so the best month makes 3.9 times the worst. November to March brings in 56% of the year's output in Copiah County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.57 m/s | 391 kWh | $59 |
| February | 3.66 m/s | 384 kWh | $58 |
| March | 3.67 m/s | 428 kWh | $64 |
| April | 3.63 m/s | 400 kWh | $60 |
| May | 3.12 m/s | 253 kWh | $38 |
| June | 2.73 m/s | 153 kWh | $23 |
| July | 2.48 m/s | 111 kWh | $17 |
| August | 2.56 m/s | 126 kWh | $19 |
| September | 2.93 m/s | 196 kWh | $30 |
| October | 3.24 m/s | 287 kWh | $43 |
| November | 3.46 m/s | 344 kWh | $52 |
| December | 3.51 m/s | 372 kWh | $56 |
What a taller tower would buy
Measured at 10 m the wind in Copiah County averages 1.94 m/s; at 50 m it is 4.06 m/s. That gives a shear exponent of 0.459, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,717 to 6,883 kWh a year, 301% 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 | 2.67 m/s | 1,717 kWh | over 100 years |
| 30 m | 3.21 m/s | 3,270 kWh | over 100 years |
| 40 m | 3.66 m/s | 5,011 kWh | over 100 years |
| 50 m | 4.06 m/s | 6,883 kWh | 97 years |
Counties around Copiah County
2 of the 6 closest counties are windier at turbine height; the windiest, Hinds County, averages 4.39 m/s.
- Lincoln County, MS: 3.02 m/s, 2,661 kWh, payback over 100 years (23 mi)
- Hinds County, MS: 4.39 m/s, 8,690 kWh, payback 76 years (28 mi)
- Claiborne County, MS: 3.21 m/s, 3,265 kWh, payback over 100 years (28 mi)
- Lawrence County, MS: 2.95 m/s, 2,455 kWh, payback over 100 years (30 mi)
- Simpson County, MS: 3.12 m/s, 2,970 kWh, payback over 100 years (31 mi)
- Jefferson County, MS: 3.61 m/s, 4,778 kWh, payback over 100 years (36 mi)
Sun versus wind in Copiah County
Copiah County gets 4.61 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,346 kWh a year; one kW of the turbine above makes 327. Kilowatt for kilowatt, panels make 4.1 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.