Wind Turbine Payback in Grant County, ND
Wind turbine payback in Grant 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 Grant County, ND averages 6.67 m/s (14.9 mph). A 10 kW turbine there would make about 24,655 kWh a year, worth $3,072 at ND's 12.46¢/kWh. Against an installed cost of about $100,000, that is a payback of 33 years, and the turbine is built to last about 20.
What to do in Grant County
A home turbine is not worth buying for savings in Grant County unless your spot is far windier than the county average, 9.1 m/s at the hub against 6.67 m/s here. Per kW, solar panels would make about 1,177 kWh a year here against the turbine's 2,466, so get a solar quote first.
What would have to change
- Power would have to cost 20¢/kWh, 1.6 times what ND pays now.
- Or the average wind at the hub would have to be 9.1 m/s instead of 6.67. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of ND
Grant County is the 82nd windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in ND is Bowman County at 6.79 m/s, payback 31 years.
Month by month in Grant County
January is the strongest month here, at 7.18 m/s and about 2,404 kWh. July is the weakest, 5.78 m/s and 1,537 kWh, so the best month makes 1.6 times the worst. November to March brings in 45% of the year's output in Grant County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 7.18 m/s | 2,404 kWh | $300 |
| February | 6.59 m/s | 1,848 kWh | $230 |
| March | 6.94 m/s | 2,262 kWh | $282 |
| April | 6.93 m/s | 2,184 kWh | $272 |
| May | 6.66 m/s | 2,090 kWh | $260 |
| June | 6.19 m/s | 1,733 kWh | $216 |
| July | 5.78 m/s | 1,537 kWh | $192 |
| August | 5.92 m/s | 1,621 kWh | $202 |
| September | 6.57 m/s | 1,969 kWh | $245 |
| October | 7.17 m/s | 2,398 kWh | $299 |
| November | 7.08 m/s | 2,269 kWh | $283 |
| December | 7.02 m/s | 2,312 kWh | $288 |
What a taller tower would buy
Measured at 10 m the wind in Grant County averages 5.33 m/s; at 50 m it is 7.41 m/s. That gives a shear exponent of 0.205, typical of ordinary open country. Going from 20 m to 50 m takes output from 20,750 to 29,920 kWh a year, 44% 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 | 6.14 m/s | 20,750 kWh | 39 years |
| 30 m | 6.67 m/s | 24,679 kWh | 33 years |
| 40 m | 7.08 m/s | 27,604 kWh | 29 years |
| 50 m | 7.41 m/s | 29,920 kWh | 27 years |
Counties around Grant County
2 of the 6 closest counties are windier at turbine height; the windiest, Hettinger County, averages 6.78 m/s.
- Morton County, ND: 6.53 m/s, 23,628 kWh, payback 34 years (29 mi)
- Sioux County, ND: 6.56 m/s, 23,849 kWh, payback 34 years (32 mi)
- Hettinger County, ND: 6.78 m/s, 25,457 kWh, payback 32 years (39 mi)
- Adams County, ND: 6.73 m/s, 25,093 kWh, payback 32 years (46 mi)
- Corson County, SD: 6.52 m/s, 23,554 kWh, payback 29 years (51 mi)
- Oliver County, ND: 6.49 m/s, 23,333 kWh, payback 34 years (55 mi)
Sun versus wind in Grant County
Grant County gets 4.03 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,177 kWh a year; one kW of the turbine above makes 2,466. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 2.1 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.