A small wind turbine electric system can be a viable renewable energy source for your home if the following conditions are met:
- your property site has enough wind
- tall towers are allowed in your area
- you have enough space on your property
- you have some extra capital for renewable energy investment.
Wind turbines work by harnessing the kinetic energy of moving air and converting it to electricity using a generator. Typically, a wind turbine mainly consists a rotor, a generator/alternator, a tower, and a tail (for stability). According to the Department of Energy, wind energy has the potential to lower your electricity bill by 50%-90%.1
To effectively harvest wind energy on your property, you first need to be sure the local zoning codes will allow you to erect a wind turbine. Since the energy potential of wind increases with the height of the turbine, you should be sure to understand the maximum height allowed by the zoning codes in your area. You can find your zoning restrictions by calling a local building inspector, board of supervisors, or a planning board in your region. You should also check if your property has enough wind to produce electricity in a practical and economic way to pay back the initial investment in a timely manner. Typically, northern Ohio has more wind resources than southern Ohio. Lastly, you should be consider the cost of the wind turbine. Installation costs vary widly based on the local zoning restrictions, permitting process, utility connection costs, and rebates available. The Department of Energy estimates that a small wind system in Ohio will cost between $3,000 and $5,000 per kilowatt (kW) of wind generation capacity. This leads to a general payback period for a wind turbine between 6-30 years depending on the system size, local wind conditions, and existing rebate programs.1
Energy Production Variables
Power production for a wind turbine is given by the following equation:5
P = k × Cp × 12 × ρ × A × v3
P = Power output, kW
Cp = Maximum power coefficient, typically ranging from 0.25 to 0.45
ρ = Air density, lb/ft3
A = Rotor swept area, ft2
V = Wind speed, mph
k = 0.000133 A constant to yield power in kilowatts.
As shown in the equation, the primary factor affecting the output power of a wind turbine is the average wind speed in your area at the specified turbine height. A small increase or decrease in wind velocity will greatly affects the turbine power output since velocity is exponentially related to the power output.
You can find the average wind speed in your area by visiting the Department of Energy’s “Ohio 30-meter Wind Map.” Generally, residential wind turbines will be lower than 30 meters. As a result, they will have a lower average velocity than provided by the map provided (something to consider for your power estimates). To get a more accurate wind speed estimate, you’ll need to contact a professional.
The rotor blade diameter, which you can control most, is also related to the power output. Power is quadratically related to rotor blade diameter, which means a small increase in the rotor diameter will result in a large power increase. You should consider increasing the rotor blade diameter as much as possible when sizing your system.
Wind turbine systems are complex electrical systems, and are not a do-it-yourself project. We recommend that you contact a professional contractor to undergo a site assessment to see if wind energy is right for you. You can find a list of Ohio installers at greenenergyohio.org's "Renewable Energy Installers in Ohio."6
1 "Small Wind Electric Systems" by U.S. Department of Energy
Detailed guide for residential implementation of Wind Energy in Ohio.
2 "Understanding Wind Power Generators for Home Use" by windpower.net
Wind energy "How It Works" guide
3 "Wind Power Calculator" by windpower.net
Wind power calculator for estimating your home's potential wind power production.
4 "Ohio 30-Meter Wind Map" by U.S. Department of Energy
Visual map of average Ohio wind speeds at 30 meters.
5 "How to calculate wind power output" by windpowerengineering.com
Detailed description of wind power output calculation.
6 "Renewable Energy Installers in Ohio" by greenenergyohio.org
List of renewable energy contractors in Ohio.