Wind Turbine Payback in Martin County, FL
Wind turbine payback in Martin 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 Martin County, FL averages 4.82 m/s (10.8 mph). A 10 kW turbine there would make about 11,341 kWh a year, worth $1,738 at FL's 15.32¢/kWh. Against an installed cost of about $100,000, that is a payback of 58 years, and the turbine is built to last about 20.
What to do in Martin County
A home turbine is not worth buying for savings in Martin County unless your spot is far windier than the county average, 7.8 m/s at the hub against 4.82 m/s here. Per kW, solar panels would make about 1,445 kWh a year here against the turbine's 1,134, so get a solar quote first.
What would have to change
- Power would have to cost 44¢/kWh, 2.9 times what FL pays now.
- Or the average wind at the hub would have to be 7.8 m/s instead of 4.82. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of FL
Martin County is the 1,546th windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in FL is Brevard County at 5.62 m/s, payback 39 years.
Month by month in Martin County
March is the strongest month here, at 5.60 m/s and about 1,422 kWh. July is the weakest, 3.45 m/s and 351 kWh, so the best month makes 4.1 times the worst. November to March brings in 55% of the year's output in Martin County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 5.47 m/s | 1,345 kWh | $206 |
| February | 5.34 m/s | 1,140 kWh | $175 |
| March | 5.60 m/s | 1,422 kWh | $218 |
| April | 5.35 m/s | 1,227 kWh | $188 |
| May | 4.87 m/s | 989 kWh | $152 |
| June | 3.86 m/s | 486 kWh | $74 |
| July | 3.45 m/s | 351 kWh | $54 |
| August | 3.64 m/s | 416 kWh | $64 |
| September | 4.29 m/s | 667 kWh | $102 |
| October | 5.15 m/s | 1,150 kWh | $176 |
| November | 5.44 m/s | 1,285 kWh | $197 |
| December | 5.39 m/s | 1,295 kWh | $198 |
What a taller tower would buy
Measured at 10 m the wind in Martin County averages 3.87 m/s; at 50 m it is 5.34 m/s. That gives a shear exponent of 0.200, typical of ordinary open country. Going from 20 m to 50 m takes output from 9,017 to 14,892 kWh a year, 65% 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 | 4.45 m/s | 9,017 kWh | 72 years |
| 30 m | 4.82 m/s | 11,350 kWh | 58 years |
| 40 m | 5.11 m/s | 13,263 kWh | 49 years |
| 50 m | 5.34 m/s | 14,892 kWh | 44 years |
Counties around Martin County
None of the 6 closest counties is windier than Martin County.
- St. Lucie County, FL: 4.78 m/s, 11,082 kWh, payback 59 years (21 mi)
- Palm Beach County, FL: 4.67 m/s, 10,382 kWh, payback 63 years (30 mi)
- Okeechobee County, FL: 4.78 m/s, 11,082 kWh, payback 59 years (37 mi)
- Indian River County, FL: 4.78 m/s, 11,082 kWh, payback 59 years (44 mi)
- Glades County, FL: 4.38 m/s, 8,632 kWh, payback 76 years (50 mi)
- Hendry County, FL: 4.29 m/s, 8,120 kWh, payback 80 years (60 mi)
Sun versus wind in Martin County
Martin County gets 4.95 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,445 kWh a year; one kW of the turbine above makes 1,134. Kilowatt for kilowatt, panels make 1.3 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.