Directory:Alternate Energy Resources/Wind Energy
Exploring Ways to Use Wind Energy
We have harnessed the wind's energy for hundreds of years—from windmills that pump water or grind grain to today's wind turbines that generate electricity.
If you live on at least one acre of land with an ample wind resource, you can generate your own electricity using a small wind electric system. You can also use a small wind turbine for pumping water.
You may have the opportunity now or in the future to buy clean electricity from a wind power plant.
Small Wind Electric Systems
Small wind electric systems are one of the most cost-effective, home-based renewable energy systems. These systems are also nonpolluting.
If a small wind electric system is right for you, it can do the following:
- Lower your electricity bills by 50–90%
- Help you avoid the high costs of having utility power lines extended to a remote location
- Help uninterruptible power supplies ride through extended utility outages.
Small wind electric systems can also be used for a variety of other applications, including water pumping on farms and ranches.
How a Small Wind Electric System Works
Wind is created by the unequal heating of the Earth's surface by the sun. Wind turbines convert the kinetic energy in wind into clean electricity.
When the wind spins the wind turbine's blades, a rotor captures the kinetic energy of the wind and converts it into rotary motion to drive the generator. The manufacturer can provide information on the maximum wind speed at which the turbine is designed to operate safely. Most turbines have automatic overspeed-governing systems to keep the rotor from spinning out of control in very high winds.
A small wind system can be connected to an electric distribution system (grid-connected) or it can stand alone (off-grid).
Evaluating a Potential Small Wind Turbine Site
A small wind energy system can provide a practical and economical source of electricity if the following apply to you:
- Your property has a good wind resource
- Your home or business is located on at least one acre of land in a rural area
- Your local zoning codes or covenants allow wind turbines
- You can determine how much electricity you need or want to produce
- It works for you economically, and you're comfortable with long-term investments
- Your average electricity bills are $150 per month or more
- Your property is in a remote location that does not have easy access to utility lines.
Small Wind Electric System Components
To capture and convert the wind's kinetic energy into electricity, a home wind energy system generally comprises the following:
- A wind turbine (blades) attached to a rotor, generator/alternator mounted on a frame, and usually a tail
- A tower
- Balance-of-system components, such as controllers, inverters, and/or batteries.
Installing and Maintaining a Small Electric Wind System
With proper installation and maintenance, a small wind electric system should last up to 20 years or longer.
Before installing your system, you first need to do the following:
- Find the best site
- Size your wind turbine
- Decide whether you'll have a grid-connected or stand-alone system
- Understand your local zoning, permitting, and neighborhood covenant requirements.
The manufacturer/dealer should be able to help you install your small wind electric system. Many people elect to install the systems themselves. Before attempting to install your wind turbine, ask yourself the following questions:
- Can I pour a proper cement foundation?
- Do I have access to a lift or a way of erecting the tower safely?
- Do I know the difference between alternating current (AC) and direct current (DC) wiring?
- Do I know enough about electricity to safely wire my turbine?
- Do I know how to safely handle and install batteries?
If you answered no to any of the above questions, you should probably choose to have your system installed by a system integrator or installer.
Contact the manufacturer for help, or contact your state energy office and local utility for a list of local system installers. You can also check the yellow pages for wind energy system service providers.
A credible installer may provide additional services such as permitting. Find out if the installer is a licensed electrician, and ask for references and check them. You may also want to check with the Better Business Bureau.
Although small wind turbines typically are sturdy and reliable machines, they do require some annual maintenance.
- Check and tighten bolts and electrical connections as necessary.
- Check machines for corrosion and the guy wires for proper tension.
- Check for and replace any worn leading edge tape on the turbine blades, if appropriate.
- Replace the turbine blades and/or bearings after 10 years if needed.
If you do not have the expertise to maintain the system, your installer may provide a service and maintenance program.
To meet the electricity needs of a power company, a number of large wind turbines (50 kilowatts up to 2 megawatts) can be built close together to form a wind plant. Several power providers today use wind plants to supply power to their customers.
Wind turbines operate on a simple principle. The energy in the wind turns two or three propeller-like blades around a rotor. The rotor is connected to the main shaft, which spins a generator. The blades act much like airplane wings. When the wind blows, a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure air pocket then pulls the blade toward it, causing the rotor to turn. This is called lift. The force of the lift is actually much stronger than the wind's force against the front side of the blade, which is called drag. The combination of lift and drag is what causes the rotor to spin.
Wind turbines are mounted on a tower to capture the most energy. At 100 feet (30 meters) or more above ground, they can take advantage of faster and less turbulent wind.
See our wind power animation for more information.