How to Make Your Own Small Wind Turbine

How to Make Your Own Small Wind Turbine

How to Make Your Own Small Wind Turbine

Introduction

Making your own small wind turbine can be a fun and rewarding project. With some basic materials and tools, you can build a turbine that will generate electricity from wind power. Small wind turbines are great for providing supplemental power to homes, cabins, boats, and RVs. In this guide, I’ll walk you through the full process of designing, building, and installing your own turbine from start to finish.

Choosing a Location

The first step is picking a good location for your wind turbine. For optimal performance, you’ll want an elevated, open site with consistent wind speeds of at least 10 mph. Stay away from turbulent, gusty areas and obstructions like buildings or trees that can block the wind. Good locations include hilltops, open fields, and shorelines. Use a wind resource map or anemometer to determine the average wind speeds in your area.

I installed my small turbine on a 15-foot tower in my backyard. This raised it above obstructions like my house and trees. My property gets steady winds of 12-15 mph, making it a prime candidate for a small wind turbine.

Selecting a Turbine Design

There are two main types of wind turbines to choose from:

Horizontal Axis Turbines

This is the classic propeller-style design where the rotor spins on a horizontal shaft parallel to the ground. The blades face into the wind to capture kinetic energy. Horizontal axis turbines are most efficient and can generate the most power. They require strong steady winds to operate well.

Vertical Axis Turbines

Vertical axis turbines have rotors that spin on a vertical shaft perpendicular to the ground. The Savonius and Darrieus designs are the most common vertical axis turbines. They are omni-directional, meaning they can harness wind from any direction without having to rotate into the wind. Vertical axis turbines work better in turbulent, gusty conditions compared to horizontal axis models. However, they are generally less efficient and produce less power overall.

For my small wind turbine project, I opted to build a horizontal axis design. This 3-blade propeller style is one of the most efficient and productive for home-scale electricity generation.

Sizing Your Turbine

Properly sizing your wind turbine is critical for getting the right amount of power output. The size depends on your location’s wind speeds, desired power production, and the swept area of the rotor blades. For a residential application, a turbine in the range of 2 to 10 kW is typical. This can provide 20%-40% of an average household’s electricity.

To choose the right size, first calculate your power requirements. For my site with 12 mph average wind speeds, a 5 kW turbine was ideal to provide supplemental power to my home. The rotor diameter ended up being 8 feet to achieve that power rating at my wind speeds. Larger blades capture more kinetic energy.

Obtaining Materials and Parts

The main components I needed to source for my wind turbine build were:

  • Rotor blades – I opted for prefabricated fiberglass blades designed specifically for small wind turbines. Make sure the length matches your target swept area.

  • Generator – This converts the rotational energy into electrical energy. A permanent magnet alternator rated for wind turbines is ideal. Match the voltage, phase, and power rating specs.

  • Tower – This raises the turbine to reach faster, less turbulent winds. You can buy a metal tower or build your own from wood. Mine was 15 feet tall.

  • Rotor hub – This connects and positions the blades onto the rotor shaft. Choose a prefabricated hub to match your generator.

  • Tail vane – This positions the turbine into the wind. I used a basic swinging tail vane kit.

  • Materials for the housing/frame – I constructed mine from wood beams, fasteners, and sheet metal. Make sure it protects the components from the elements.

Shop around to find the best parts and prices for your particular wind turbine design. Buy the highest quality you can afford for longevity.

Constructing the Turbine Housing

The turbine housing holds and protects all the working components. I built mine from 2×4 lumber framed together into a square structure. The generator, blades, and rotor hub mount inside this housing. I covered it with angled sheet metal to create an aerodynamic shell and keep out precipitation.

Make sure to include a hinged access door so you can maintain the turbine’s interior. Also add a vent so excess heat can escape on hot days. Install all components securely according to the manufacturers’ specifications using bolts, braces, and vibration pads.

Assembling the Rotor and Blades

First I mounted the rotor hub to the generator shaft. Then I bolted on the three blades at equal spacing around the hub. Proper blade alignment and pitch are critical for smooth operation and power production. I set my blades at a 10 degree pitch using a protractor. This angle optimizes the lift from my particular airfoil blade shape.

The rotor assembly should spin freely with minimal friction. Check that the blades clear the housing at all points during rotation. Add spacers or shims as needed to prevent rubbing.

Mounting the Turbine

With the wind turbine fully assembled, it was ready to mount on my tower. I used a gin pole system with a pulley and winch to lift it into place. Guys wires anchored around the base stabilized the tower against lateral forces from the wind.

For electrical wiring, I ran the cable down through the inside of the tower conduit. This protects the wires and keeps them hidden. At the base, I installed a weatherproof box with a disconnect switch, surge protector, inverter, and meter.

Testing and Operation

After completion, I spun up the rotor manually to verify smooth rotation. Then came the fun part – watching it generate power from the wind for the first time! It took some fine tuning to get the yaw positioning dialed in for optimal alignment into the wind.

Routine maintenance is critical for longevity and performance. I check for loose bolts, debris buildup, and wear and tear every 6 months. So far my DIY wind turbine has been providing clean renewable power for 2 years and counting! Let me know if you have any other questions about designing and building your own.