Wind Turbine Payback in Calvert County, MD
Wind turbine payback in Calvert 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 Calvert County, MD averages 5.21 m/s (11.7 mph). A 10 kW turbine there would make about 13,976 kWh a year, worth $2,978 at MD's 21.31¢/kWh. Against an installed cost of about $100,000, that is a payback of 34 years, and the turbine is built to last about 20.
What to do in Calvert County
A home turbine is not worth buying for savings in Calvert County unless your spot is far windier than the county average, 6.5 m/s at the hub against 5.21 m/s here. Per kW, solar panels would make about 1,238 kWh a year here against the turbine's 1,398, so get a solar quote first.
What would have to change
- Power would have to cost 36¢/kWh, 1.7 times what MD pays now.
- Or the average wind at the hub would have to be 6.5 m/s instead of 5.21. A taller tower or an exposed ridge can add some of that; a rooftop never will.
Against the rest of MD
Calvert County is the 1,373rd windiest of 3,144 US counties at turbine height; the national middle is 4.79 m/s. The windiest in MD is Worcester County at 7.01 m/s, payback 17 years.
Month by month in Calvert County
March is the strongest month here, at 6.04 m/s and about 1,701 kWh. August is the weakest, 3.96 m/s and 543 kWh, so the best month makes 3.1 times the worst. November to March brings in 55% of the year's output in Calvert County.
| Month | Wind at 30 m | Output | Worth |
|---|---|---|---|
| January | 6.03 m/s | 1,695 kWh | $361 |
| February | 6.07 m/s | 1,551 kWh | $331 |
| March | 6.04 m/s | 1,701 kWh | $362 |
| April | 5.84 m/s | 1,522 kWh | $324 |
| May | 4.93 m/s | 1,026 kWh | $219 |
| June | 4.47 m/s | 753 kWh | $160 |
| July | 4.00 m/s | 558 kWh | $119 |
| August | 3.96 m/s | 543 kWh | $116 |
| September | 4.59 m/s | 815 kWh | $174 |
| October | 5.28 m/s | 1,228 kWh | $262 |
| November | 5.62 m/s | 1,388 kWh | $296 |
| December | 5.73 m/s | 1,506 kWh | $321 |
What a taller tower would buy
Measured at 10 m the wind in Calvert County averages 4.04 m/s; at 50 m it is 5.86 m/s. That gives a shear exponent of 0.231, typical of ordinary open country. Going from 20 m to 50 m takes output from 10,839 to 18,669 kWh a year, 72% 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 | 4.74 m/s | 10,839 kWh | 43 years |
| 30 m | 5.21 m/s | 13,961 kWh | 34 years |
| 40 m | 5.57 m/s | 16,512 kWh | 28 years |
| 50 m | 5.86 m/s | 18,669 kWh | 25 years |
Counties around Calvert County
2 of the 6 closest counties are windier at turbine height; the windiest, St. Mary's County, averages 5.43 m/s.
- St. Mary's County, MD: 5.43 m/s, 15,534 kWh, payback 30 years (21 mi)
- Talbot County, MD: 5.21 m/s, 13,976 kWh, payback 34 years (25 mi)
- Charles County, MD: 4.04 m/s, 6,780 kWh, payback 69 years (26 mi)
- Dorchester County, MD: 5.21 m/s, 13,976 kWh, payback 34 years (27 mi)
- Prince George's County, MD: 5.23 m/s, 14,116 kWh, payback 33 years (27 mi)
- Westmoreland County, VA: 3.63 m/s, 4,862 kWh, payback over 100 years (32 mi)
Sun versus wind in Calvert County
Calvert County gets 4.24 kWh of sunshine per square metre a day on average. One kW of solar panels here would make roughly 1,238 kWh a year; one kW of the turbine above makes 1,398. This is one of the rare places where a kilowatt of turbine out-produces a kilowatt of panels, by 1.1 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.