Wind Turbine Payback in Terrebonne Parish, LA
Wind turbine payback in Terrebonne Parish
No. The turbine wears out before it pays for itself.
At 30 m, the height a home turbine tower usually reaches, the wind in Terrebonne Parish, LA averages 5.23 m/s (11.7 mph). A 10 kW turbine there would make about 14,116 kWh a year, worth $1,873 at LA's 13.27¢/kWh. Against an installed cost of about $100,000, that is a payback of 53 years, and the turbine is built to last about 20.
What to do in Terrebonne Parish
A home turbine is not worth buying for savings in Terrebonne Parish unless your spot is far windier than the county average, 8.6 m/s at the hub against 5.23 m/s here. Per kW, solar panels would make about 1,384 kWh a year here against the turbine's 1,412, so get a solar quote first.
What would have to change
- Power would have to cost 35¢/kWh, 2.7 times what LA pays now.
- Or the average wind at the hub would have to be 8.6 m/s instead of 5.23. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of LA
Terrebonne Parish is the 1,360th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in LA is Iberia Parish at 5.86 m/s, payback 40 years.
Month by month in Terrebonne Parish
January is the strongest month here, at 6.25 m/s and about 1,829 kWh. July is the weakest, 3.70 m/s and 437 kWh, so the best month makes 4.2 times the worst. November to March brings in 57% of the year's output in Terrebonne Parish.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.25 m/s | 1,829 kWh | $243 |
| February | 6.22 m/s | 1,636 kWh | $217 |
| March | 5.98 m/s | 1,663 kWh | $221 |
| April | 5.96 m/s | 1,593 kWh | $211 |
| May | 5.03 m/s | 1,082 kWh | $144 |
| June | 4.17 m/s | 612 kWh | $81 |
| July | 3.70 m/s | 437 kWh | $58 |
| August | 3.77 m/s | 464 kWh | $62 |
| September | 4.62 m/s | 828 kWh | $110 |
| October | 5.31 m/s | 1,248 kWh | $166 |
| November | 5.71 m/s | 1,444 kWh | $192 |
| December | 6.13 m/s | 1,755 kWh | $233 |
What a taller tower would buy
Measured at 10 m the wind in Terrebonne Parish averages 4.25 m/s; at 50 m it is 5.76 m/s. That gives a shear exponent of 0.189, typical of ordinary open country. Going from 20 m to 50 m takes output from 11,499 to 17,932 kWh a year, 56% 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 | 4.84 m/s | 11,499 kWh | 66 years |
| 30 m | 5.23 m/s | 14,115 kWh | 53 years |
| 40 m | 5.52 m/s | 16,197 kWh | 47 years |
| 50 m | 5.76 m/s | 17,932 kWh | 42 years |
Counties around Terrebonne Parish
2 of the 6 closest counties are windier at turbine height; the windiest, Jefferson Parish, averages 5.56 m/s.
- Lafourche Parish, LA: 5.23 m/s, 14,116 kWh, payback 53 years (29 mi)
- Assumption Parish, LA: 4.84 m/s, 11,472 kWh, payback 66 years (42 mi)
- St. Mary Parish, LA: 5.5 m/s, 16,037 kWh, payback 47 years (43 mi)
- St. James Parish, LA: 4.7 m/s, 10,571 kWh, payback 71 years (48 mi)
- St. Charles Parish, LA: 4.7 m/s, 10,571 kWh, payback 71 years (49 mi)
- Jefferson Parish, LA: 5.56 m/s, 16,471 kWh, payback 46 years (50 mi)
Sun versus wind in Terrebonne Parish
Terrebonne Parish gets 4.74 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,384 kWh a year; one kW of the turbine above makes 1,412. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.0 times. 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.