Wind Turbine Payback in Penobscot County, ME
Wind turbine payback in Penobscot 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 Penobscot County, ME averages 3.57 m/s (8 mph). A 10 kW turbine there would make about 4,612 kWh a year, worth $1,394 at ME's 30.23¢/kWh. Against an installed cost of about $100,000, that is a payback of 72 years, and the turbine is built to last about 20.
What to do in Penobscot County
A home turbine is not worth buying for savings in Penobscot County unless your spot is far windier than the county average, 5.6 m/s at the hub against 3.57 m/s here. Per kW, solar panels would make about 1,034 kWh a year here against the turbine's 461, so get a solar quote first.
What would have to change
- Power would have to cost 108¢/kWh, 3.6 times what ME pays now.
- Or the average wind at the hub would have to be 5.6 m/s instead of 3.57. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of ME
Penobscot County is the 2,441st windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in ME is Knox County at 6.26 m/s, payback 15 years.
Month by month in Penobscot County
March is the strongest month here, at 4.32 m/s and about 702 kWh. July is the weakest, 2.86 m/s and 187 kWh, so the best month makes 3.8 times the worst. November to March brings in 56% of the year's output in Penobscot County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 4.00 m/s | 559 kWh | $169 |
| February | 4.28 m/s | 620 kWh | $187 |
| March | 4.32 m/s | 702 kWh | $212 |
| April | 3.95 m/s | 522 kWh | $158 |
| May | 3.37 m/s | 324 kWh | $98 |
| June | 3.11 m/s | 241 kWh | $73 |
| July | 2.86 m/s | 187 kWh | $57 |
| August | 2.88 m/s | 193 kWh | $58 |
| September | 3.18 m/s | 261 kWh | $79 |
| October | 3.56 m/s | 388 kWh | $117 |
| November | 3.62 m/s | 395 kWh | $119 |
| December | 3.77 m/s | 465 kWh | $141 |
What a taller tower would buy
Measured at 10 m the wind in Penobscot County averages 2.23 m/s; at 50 m it is 4.44 m/s. That gives a shear exponent of 0.428, typical of rough, sheltered ground: trees or buildings slow the low wind a lot. Going from 20 m to 50 m takes output from 2,600 to 8,982 kWh a year, 245% 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 m/s | 2,600 kWh | over 100 years |
| 30 m | 3.57 m/s | 4,604 kWh | 72 years |
| 40 m | 4.04 m/s | 6,757 kWh | 49 years |
| 50 m | 4.44 m/s | 8,982 kWh | 37 years |
Counties around Penobscot County
4 of the 6 closest counties are windier at turbine height; the windiest, Hancock County, averages 4.76 m/s.
- Piscataquis County, ME: 3.89 m/s, 6,037 kWh, payback 55 years (41 mi)
- Washington County, ME: 4.11 m/s, 7,143 kWh, payback 46 years (60 mi)
- Hancock County, ME: 4.76 m/s, 10,954 kWh, payback 30 years (60 mi)
- Somerset County, ME: 3.92 m/s, 6,182 kWh, payback 54 years (63 mi)
- Waldo County, ME: 3.48 m/s, 4,250 kWh, payback 78 years (68 mi)
- Kennebec County, ME: 3.51 m/s, 4,368 kWh, payback 76 years (87 mi)
Sun versus wind in Penobscot County
Penobscot County gets 3.54 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,034 kWh a year; one kW of the turbine above makes 461. Kilowatt for kilowatt, panels make 2.2 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.