Wind Turbine Payback Period Calculator
Calculate how long a home wind turbine takes to pay for itself.
Factor in installation cost, annual output, and electricity savings.
The wind turbine payback period is the time it takes for electricity savings and revenue to recover the full installation cost. Unlike solar, small wind turbines require consistent wind resources to achieve reasonable payback periods.
The Formula:
Payback Period (years) = Net System Cost / Annual Energy Value
Net System Cost = Installed cost − Tax credits − Grants
Annual Energy Value = Annual kWh produced × Electricity rate
Annual kWh Estimate:
Annual output (kWh) = Turbine capacity (kW) × Capacity factor × 8,760 hours/year
Capacity factors for small wind:
- Low wind site (5–6 m/s average): 15–20%
- Good wind site (7 m/s): 25–30%
- Excellent site (8+ m/s): 30–40%
Worked Example:
- 10 kW turbine, installed cost: $40,000
- US federal 30% ITC: −$12,000
- Net cost: $28,000
Site average wind speed: 7 m/s → capacity factor = 28%
Annual output = 10 × 0.28 × 8,760 = 24,528 kWh
Electricity rate: $0.15/kWh
Annual value = 24,528 × 0.15 = $3,679/year
Payback = $28,000 / $3,679 = 7.6 years
With typical 20-year turbine life: 20 − 7.6 = 12.4 years of effectively free electricity
Wind Speed Rules of Thumb:
| Average Wind Speed | Small Turbine Viability |
|---|---|
| Below 5 m/s | Not economical |
| 5–6.5 m/s | Marginal |
| 6.5–8 m/s | Good |
| Above 8 m/s | Excellent |
Practical Tips:
- Install an anemometer at hub height for 12 months before investing — wind data is everything
- Turbines need 10 m clearance above any obstacle within 100 m
- Noise and visual impact regulations vary by municipality — check zoning before purchasing