Wind Turbine Payback in Coos County, NH
Wind turbine payback in Coos 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 Coos County, NH averages 3.54 m/s (7.9 mph). A 10 kW turbine there would make about 4,489 kWh a year, worth $1,208 at NH's 26.91¢/kWh. Against an installed cost of about $100,000, that is a payback of 83 years, and the turbine is built to last about 20.
What to do in Coos County
A home turbine is not worth buying for savings in Coos County unless your spot is far windier than the county average, 5.8 m/s at the hub against 3.54 m/s here. Per kW, solar panels would make about 1,025 kWh a year here against the turbine's 449, so get a solar quote first.
What would have to change
- Power would have to cost 111¢/kWh, 4.1 times what NH pays now.
- Or the average wind at the hub would have to be 5.8 m/s instead of 3.54. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of NH
Coos County is the 2,473rd windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in NH is Cheshire County at 3.64 m/s, payback 76 years.
Month by month in Coos County
March is the strongest month here, at 4.28 m/s and about 684 kWh. August is the weakest, 2.76 m/s and 165 kWh, so the best month makes 4.1 times the worst. November to March brings in 60% of the year's output in Coos County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.15 m/s | 623 kWh | $168 |
| February | 4.43 m/s | 682 kWh | $184 |
| March | 4.28 m/s | 684 kWh | $184 |
| April | 3.99 m/s | 537 kWh | $145 |
| May | 3.35 m/s | 318 kWh | $86 |
| June | 2.99 m/s | 211 kWh | $57 |
| July | 2.78 m/s | 170 kWh | $46 |
| August | 2.76 m/s | 165 kWh | $44 |
| September | 2.97 m/s | 207 kWh | $56 |
| October | 3.40 m/s | 336 kWh | $90 |
| November | 3.63 m/s | 401 kWh | $108 |
| December | 3.90 m/s | 518 kWh | $139 |
What a taller tower would buy
Measured at 10 m the wind in Coos County averages 2.29 m/s; at 50 m it is 4.34 m/s. That gives a shear exponent of 0.397, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,650 to 8,403 kWh a year, 217% 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 | 3.02 m/s | 2,650 kWh | over 100 years |
| 30 m | 3.54 m/s | 4,503 kWh | 83 years |
| 40 m | 3.97 m/s | 6,438 kWh | 58 years |
| 50 m | 4.34 m/s | 8,403 kWh | 44 years |
Counties around Coos County
4 of the 6 closest counties are windier at turbine height; the windiest, Franklin County, averages 3.87 m/s.
- Essex County, VT: 3.6 m/s, 4,736 kWh, payback 88 years (22 mi)
- Oxford County, ME: 3.52 m/s, 4,408 kWh, payback 75 years (29 mi)
- Caledonia County, VT: 3.6 m/s, 4,736 kWh, payback 88 years (42 mi)
- Franklin County, ME: 3.87 m/s, 5,942 kWh, payback 56 years (48 mi)
- Orleans County, VT: 3.77 m/s, 5,477 kWh, payback 76 years (49 mi)
- Carroll County, NH: 3.51 m/s, 4,368 kWh, payback 85 years (54 mi)
Sun versus wind in Coos County
Coos County gets 3.51 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,025 kWh a year; one kW of the turbine above makes 449. Kilowatt for kilowatt, panels make 2.3 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.