Wind Turbine Payback in Simpson County, MS
Wind turbine payback in Simpson 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 Simpson County, MS averages 3.12 m/s (7 mph). A 10 kW turbine there would make about 2,970 kWh a year, worth $447 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 Simpson County
A home turbine is not worth buying for savings in Simpson County unless your spot is far windier than the county average, 7.9 m/s at the hub against 3.12 m/s here. Per kW, solar panels would make about 1,349 kWh a year here against the turbine's 297, so get a solar quote first.
What would have to change
- Power would have to cost 168¢/kWh, 11.2 times what MS pays now.
- Or the average wind at the hub would have to be 7.9 m/s instead of 3.12. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MS
Simpson County is the 2,974th 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 Simpson County
March is the strongest month here, at 3.55 m/s and about 384 kWh. July is the weakest, 2.41 m/s and 100 kWh, so the best month makes 3.8 times the worst. November to March brings in 55% of the year's output in Simpson County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 3.45 m/s | 352 kWh | $53 |
| February | 3.52 m/s | 339 kWh | $51 |
| March | 3.55 m/s | 384 kWh | $58 |
| April | 3.53 m/s | 366 kWh | $55 |
| May | 3.05 m/s | 234 kWh | $35 |
| June | 2.62 m/s | 133 kWh | $20 |
| July | 2.41 m/s | 100 kWh | $15 |
| August | 2.50 m/s | 116 kWh | $17 |
| September | 2.86 m/s | 181 kWh | $27 |
| October | 3.20 m/s | 275 kWh | $41 |
| November | 3.40 m/s | 323 kWh | $49 |
| December | 3.41 m/s | 337 kWh | $51 |
What a taller tower would buy
Measured at 10 m the wind in Simpson County averages 1.88 m/s; at 50 m it is 3.95 m/s. That gives a shear exponent of 0.461, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 1,541 to 6,329 kWh a year, 311% 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 | 2.59 m/s | 1,541 kWh | over 100 years |
| 30 m | 3.12 m/s | 2,974 kWh | over 100 years |
| 40 m | 3.56 m/s | 4,586 kWh | over 100 years |
| 50 m | 3.95 m/s | 6,329 kWh | over 100 years |
Counties around Simpson County
2 of the 6 closest counties are windier at turbine height; the windiest, Rankin County, averages 3.64 m/s.
- Jefferson Davis County, MS: 2.95 m/s, 2,455 kWh, payback over 100 years (24 mi)
- Rankin County, MS: 3.64 m/s, 4,905 kWh, payback over 100 years (25 mi)
- Smith County, MS: 2.96 m/s, 2,484 kWh, payback over 100 years (26 mi)
- Lawrence County, MS: 2.95 m/s, 2,455 kWh, payback over 100 years (27 mi)
- Covington County, MS: 2.92 m/s, 2,370 kWh, payback over 100 years (29 mi)
- Copiah County, MS: 3.21 m/s, 3,265 kWh, payback over 100 years (31 mi)
Sun versus wind in Simpson County
Simpson County gets 4.62 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,349 kWh a year; one kW of the turbine above makes 297. Kilowatt for kilowatt, panels make 4.5 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.