Introduction
With energy costs on the rise, many homeowners are looking for ways to reduce their dependence on the electric grid. Installing small wind turbines is one way to generate your own renewable electricity and slash your energy bills. DIY wind turbines are an affordable option that can be customized to suit your needs and work with the wind speeds in your area.
In this comprehensive guide, I'll cover everything you need to know about designing, building, and installing your own wind turbine system. I'll provide tips on how to determine if your property is suitable, choose the right turbine size, select optimal materials, and safely mount your turbine. I'll also share advice on integrating wind power into your existing electrical system to get the most out of your investment.
Whether you're a beginner or have some prior wind power experience, you'll find all the guidance you need to successfully harness wind energy for residential use and take control of your energy costs.
Assessing Your Property's Wind Resource
The first step in any wind turbine project is determining if your property has adequate wind speeds to generate sufficient electricity. You'll need consistent annual wind speeds of at least 10 mph for a grid-connected turbine system. For off-grid battery charging, 5-8 mph may suffice depending on your power needs.
To find out your average wind speeds:
-
Check wind maps that show estimated speeds in your area. The U.S. Department of Energy has detailed state wind maps.
-
Use data from the nearest airport or meteorological station.
-
Monitor onsite wind speeds at hub height (30+ feet high) for several months with an anemometer.
You'll get the most accurate wind resource assessment from onsite measurements. Compare wind speeds at different times of day and different seasons to see when wind peaks at your location. Focus on the windiest months when sizing your system.
Ideally, choose a site with few obstructions and turbulence. Elevated, open areas almost always have better wind flow than sheltered valleys or heavily forested land.
Selecting an Appropriate Turbine Size
Once you know your site's wind speeds, you can select a turbine rated for those conditions. In general, faster winds allow larger turbines that can generate more electricity.
Small turbines (1-10 kW) are best for residential use in areas with average wind speeds of 4-6 m/s (9-14 mph). They typically have rotor diameters up to 24 feet. These turbines can directly power appliances or charge batteries when used off-grid.
For sites with excellent wind resources (6-7 m/s or 15-18 mph), medium turbines (10-50 kW) may be suitable. They can have rotors up to 40 feet across and produce enough power for multiple houses.
Always match the turbine size to your particular wind speeds. Undersized turbines won't generate as much energy. Oversized turbines may not function well in speeds lower than their rating.
DIY Wind Turbine Design Types
There are two main design options for homebuilt wind turbines:
-
Horizontal axis - The rotor spins perpendicular to the wind flow around a horizontal shaft like classic windmills. Most commercial turbines use this style.
-
Vertical axis - The rotor spins parallel to wind flow around a vertical shaft. The Savonius and Darrieus models are common vertical axis turbines.
Horizontal axis turbines generally produce more power for a given size. But vertical designs have advantages like omnidirectional operation that make them worth considering for DIY builds.
Research both types or consult wind energy experts to pick the right model for your project goals and site. You can also explore hybrid vertical/horizontal designs.
Choosing Reliable DIY Wind Turbine Kits
Purchasing a DIY wind turbine kit with prefabricated parts is the easiest route to take when building your own. Reputable kits include everything you need like blades, generators, towers, and wiring.
When comparing kits, look for:
- Durable blades (usually fiberglass) rated for high winds and weather
- Efficient alternators or generators with power ratings for different wind speeds
- Towers tall enough to access stronger winds above roof level
- UL-certified electrical components like inverters for grid connection
- Detailed manuals with safety guidelines and installation instructions
Kits that meet certification standards offer proven designs that will hold up over many years of operation. Investing in quality parts saves headaches down the road.
Key Wind Turbine Materials and Components
If you want to build a wind turbine from scratch, you'll need to source many specific materials and components. Here are some of the main items:
-
Blades - Lightweight wood, metal alloys, or composites like fiberglass. Must be aerodynamically shaped and precisely balanced.
-
Generator or alternator - Produces AC or DC power. Permanent magnet or wound rotor designs are common. Should be sized for expected wind speeds.
-
Gearbox (optional) - Increases rotor rpm for generators that operate at higher speeds. Not always needed for direct drive generators.
-
Tower - Steel monopoles or lattice towers that elevate the turbine to optimal height. Must withstand all wind and weather conditions at the site.
-
Inverter - (For grid-tied systems) Converts generator power from AC to DC for feeding the grid. Must adhere to your local interconnection standards.
-
Batteries and charge controller - (For off-grid systems) Stores power and regulates charging/discharging. Deep cycle lead-acid batteries are standard.
-
Wiring and disconnects - UL-listed wiring suitable for outdoor use. Disconnects required for safe emergency turbine shutdowns.
Mounting Your Wind Turbine Properly
Proper turbine mounting is critical for safety and performance. The tower must elevate the turbine to get it clear of wind turbulence:
-
Minimum height - 20 feet above any surrounding obstacles within 300 feet.
-
Optimal height - 100 feet or more above ground for access to stronger, steadier winds.
The tower must withstand the turbine's vibrations, weight shifting, and thrust forces. Guy wires help stabilize freestanding towers.
Most residential turbines are mounted on:
-
Tubular monopole towers - Strong round steel pipes planted in concrete foundations.
-
Lattice or triangle towers - Three or four steel legs bolted together. Requires climbing ladders for maintenance.
-
Rooftop mounting - Only if your roof trusses can bear the weight and wind forces. Usually suboptimal for performance.
Proper siting and a stable foundation are also critical. Position the turbine upwind of buildings or trees and anchor tower footings below the frost line.
Integrating Your Wind Turbine With the Electrical System
To utilize the power your wind turbine generates, it needs to connect to your electrical system properly. This includes:
-
Batteries - For off-grid systems, select batteries sized for your power needs and turbine output. Use a charge controller to avoid overcharging.
-
Inverter - Grid-tied systems require an inverter for converting turbine power to match the grid AC. Must meet all interconnection standards.
-
Breakers and disconnects - Critical for isolating the turbine and safely shutting it down in high winds or malfunctions.
-
Wire sizing - Electrical wiring must be thick enough for the rated turbine power output. Follow all codes for home electricity systems.
-
Net metering - In areas with net metering, your turbine can spin your home electric meter backwards when generating excess power. Check with your utility company.
Consult with an electrician for proper installation and permits. Never connect your turbine directly to the grid without an inverter and interconnection approval.
Obtaining Proper Permits and Approvals
Most residential wind turbine projects require some form of permitting or approval from local authorities:
-
Zoning permit - Confirms wind turbines are allowed under land use codes for your property.
-
Building permit - Required for constructing the turbine tower foundation and all electrical work.
-
Inspection - An electrical inspection will verify correct wiring methods were used.
-
Interconnection agreement - For grid-tied systems, an approved agreement with your utility is mandatory for feeding power to the grid.
-
HOA approval - If subject to a homeowners association, you'll need written approval prior to installation.
-
Aviation and environmental permits - May be needed depending on turbine size and potential wildlife impacts.
Submit applications early in your planning process. Getting permits can take weeks or even months.
Practicing Proper Safety During Wind Turbine Operation
Correct turbine siting, engineering, and installation are vital for safety, but you must also operate and maintain the system properly:
-
Monitor weather closely and shut down the turbine in high winds or severe storms to prevent damage.
-
Turn off and secure the turbine when performing any inspections or maintenance.
-
Never approach the turbine while it's operating. Keep a safe distance away from the spinning blades at all times.
-
Watch for signs of wear like fraying guy wires or tower welds and repair immediately.
-
Grease bearings twice a year. Replace worn bearings to prevent catastrophic failures.
-
Inspect blades and electrical wiring for cracks, corrosion, and other degradation annually.
Conclusion
Installing your own wind turbine is an involved but rewarding project that lets you take charge of your energy supply. With proper planning, design, component selection, installation, and maintenance, a residential wind turbine can provide clean power and energy bill savings for years to come. Use this guide to make your DIY wind project a success!