Do Small Wind Turbines Really Generate Enough Electricity for the Average Home?
Small wind turbines, also known as residential wind turbines, have become an increasingly popular way for homeowners to generate their own electricity. But how much power can these small turbines realistically produce? Can they generate enough electricity to meet the needs of the average household? In this article, we’ll take an in-depth look at whether small wind turbines live up to their promise.
What are Small Wind Turbines?
Small wind turbines are wind turbines that produce electricity on a small scale for residential or light commercial use. They typically have capacities below 50 kilowatts (kW). In contrast, large commercial wind turbines can have capacities of 1 megawatt (MW) or more.
Some key features of small wind turbines:
- Tower heights usually around 30-80 feet.
- Blade diameters of 6-20 feet.
- Designed to supplement electricity purchased from the utility grid. Can be connected to the grid or be off-grid.
- Used by homeowners, farmers, businesses, etc.
- Costs range from $3,000 to $50,000 installed.
Residential wind turbines are on the smaller end of the small wind turbine range, with capacities of 10 kW or less.
How Much Electricity Do They Produce?
The amount of electricity generated by a small wind turbine depends on several factors:
- Wind speeds – Higher average wind speeds produce more electricity.
- Turbine size – More kilowatts and larger blades capture more wind energy.
- Location – Turbines located in windier sites will produce more.
- Tower height – In general, higher towers access faster wind speeds at higher altitudes.
According to the U.S. Department of Energy (DOE), a typical home wind turbine can generate anywhere from 400 to 900 kilowatt-hours per month, on average.
- The average U.S. home uses about 10,000 kWh per year, or around 830 kWh per month.
- So a residential turbine could potentially offset 40-100% of an average home’s electricity usage.
However, real-world energy production depends heavily on the specific turbine model, tower height, wind resource, and other siting factors.
To illustrate variability, here are electricity production numbers from real-world installations:
- A 2.5 kW turbine (small for residential use) in Oklahoma generates 1,500 kWh/year.
- A 10 kW turbine (larger residential size) in Minnesota generates 9,500 kWh/year.
- A 10 kW turbine in California generates 16,500 kWh/year.
The Minnesota turbine offsets about 95% of an average home’s use, while the California turbine offsets over 160%. Location makes a big difference.
What Factors Determine Productivity?
The main factors that determine how much electricity a wind turbine produces are:
- As a general rule, each 1 mph increase in wind speed produces a 5% increase in power output.
- Most small turbines require average annual wind speeds of at least 9 mph to be productive, and at least 11 mph to achieve the higher end of their output range.
- Unfortunately, many urban and suburban areas do not reach these wind speeds.
- More kilowatts and larger rotors capture more wind energy. For example, upgrading from a 5 kW to 10 kW turbine doubles output.
- Most residential turbines are in the 2.5-10 kW range. Larger turbines become prohibitively expensive.
- Wind speeds increase with height above ground. A turbine on a 100 ft tower will be exposed to faster winds than on a 60 ft tower.
- Most residential turbines are mounted on 80-120 ft towers to reach sufficient wind speeds.
- Taller towers cost more but greatly boost production – often worth the extra investment.
- Choose sites with the highest average wind speeds possible. In general, more open areas – and areas higher above sea level – are windier.
- Use wind resource maps to compare potential sites. Also consider local obstructions like buildings and trees.
- Work with wind experts to choose a turbine site with adequate wind resources.
Are Small Wind Turbines Worth It?
For many homeowners, the answer depends on:
Cost – Small wind systems are expensive, with installed costs averaging $50,000 or more. Federal and state incentives can help offset costs. Focus on long-term value.
Wind speeds – You need sufficient wind resources. If your location has average wind speeds below 9 mph, small wind likely won’t be productive enough to justify the investment. Use a wind resource map to check.
Goals – Decide how much of your power needs you want wind to offset. Small turbines can meet a portion of household electricity demand, though likely not 100% for most.
Budget – Make sure you can afford the significant upfront costs, keeping incentives in mind. The long-term energy savings can make the investment pay off.
With the right conditions and expectations, residential wind turbines can be an excellent option for homeowners wanting to generate their own renewable electricity. But conduct careful siting and research to ensure wind works for your situation.