Wind turbines are a growing source of renewable energy. Most modern turbines convert the kinetic energy from the movement of wind into electricity. The amount of electricity that they can produce, though, depends on how much wind there is in a particular area.
Wind turbines come in many different shapes and sizes. They can generate electricity for public grids or individual homes, farms, and businesses.
What Are Wind Turbines?
Wind turbines are tools that are used to generate clean, renewable energy. Sources of clean renewable energy don’t generate harmful waste or depend on limited resources. This means that we have them as a source of energy for as long as we can maintain the equipment that harnesses it — in this case, the turbines.
There are a wide variety of wind turbines, but they fall into four general categories:
- Micro. These have limited uses, like charging the batteries on recreational vehicles and sailboats. They range in electrical output from 200 to 500 watts.
- Distributed. These are small turbines that are meant to power a single person’s property. They can be hooked up to public utility grids with permission and cooperation from your local energy supplier. They can be made to generate anywhere from 20 to 100 kilowatts.
- Land-based. These are often grouped into large wind plants or wind farms. They can generate substantial amounts of electricity for a public grid. They range in output from 100 kilowatts to many megawatts.
- Offshore. These tend to be towering structures. Many are taller than the Statue of Liberty. They generate massive amounts of energy from strong ocean winds.
What Is Wind?
Wind is a form of solar energy. It’s caused by an uneven distribution of heat among all of the molecules that form the air.
The conditions that generate wind include:
- The sun unevenly heating Earth’s atmosphere
- Earth’s bumpy and irregular surface
- Earth’s rotation
We’ll have wind in the world as long as these conditions are met. This means that we can turn as much of it into energy as we want, and there’ll always be more.
Are Wind Turbines Efficient?
Just because wind turbines generate sustainable energy doesn’t mean that they do so efficiently. Wind turbine sustainability is not a measure of their efficiency.
The efficiency of a wind turbine depends on the design and how much wind it encounters. Luckily, very small changes in wind speed translate to large increases in power, so the machines can be very efficient.
There are two main types of blades for a wind turbine — ones with a vertical axis and ones with a horizontal axis. Vertical-axis turbines are the kind that you’re most familiar with. They look like giant, minimalist fans with an average of three blades. These only work when they’re facing the wind.
Horizontal-axis turbines come in a number of different styles and designs. These can harness the wind’s energy from multiple angles, so they don’t need to be adjusted when the wind changes direction.
The most important factor in determining a wind turbine's efficiency is how much wind is in an area. The amount of wind that any particular area gets depends on a number of conditions — like the surrounding geography. In general, the higher up in the atmosphere you go, the more wind there is.
Many different wind turbine brands exist. Some come with efficiency ratings to help you evaluate the product. One example is a rated annual energy value. This value is the total amount of energy that your turbine would generate during a one-year period when the average wind speed is 11.2 miles per hour.
How do Wind Turbines Work?
Energy flow through a wind turbine is the exact opposite of a fan. For example, consider your basic window fan. It takes the energy from the electricity in your wall outlet and converts it into the movement of air molecules — a form of kinetic energy.
A wind turbine takes the kinetic energy from the air molecules in the wind and converts it into useable energy. A wind turbine can be set up to generate either mechanical or electrical energy. Mechanical power is used to perform a specific and immediate task, like pumping water or grinding grains. Electricity, on the other hand, can be stored and has a wide range of uses.
Electrical turbines are much more efficient than mechanical ones. These days, more people are using small electrical turbines even for fixed tasks like pumping water.
The main way that a wind turbine generates power is through the motion of its aerodynamically designed blades. These function a lot like airplane wings. When the wind moves against the blades, the air pressure shifts, and both lifting and dragging forces are created. The lift forces are stronger and cause the blades to spin.
The spinning blades are attached to a rotor that spins a generator. The generator is capable of converting motion into electricity.
Where Should You Put a Wind Turbine?
The exact placement of a wind turbine depends on a number of factors, including:
- What you need to do with it
- What model you’re using
- Your environment
In general, small personal turbines should be placed so that the bottom blade is at least 30 feet above the ground and 300 feet away from any obstacles. The larger turbines used in wind farms should be positioned at least 100 feet or more above the ground.
What Are Wind Turbines Made of?
Wind turbines can be made from many materials depending on the type and manufacturer. They require solid foundations that are typically concrete. Pipe, tubing, and wires are all parts of many designs.
Although different materials can work for the frames, you should avoid all aluminum turbines. These can crack and become unstable.
Are Wind Turbines Loud?
Wind turbines do generate noise. The exact amount depends on the size and model of the wind turbine.
Small turbines that generate two kilowatts of energy produce a 50-decibel sound. If you’re listening, this sound can be heard from 50 feet away. Larger turbines will likely generate more sound.
Is a Wind Turbine the Right Choice for My Home?
More and more people are considering wind turbines to help sustain their off-grid energy needs and to offset rising energy costs. Wind turbines aren’t right for every property, but you can use them in a number of ways, such as:
- Part of a hybrid energy system that also uses sources like solar energy
- Connection with your local grid — you’ll need to contact your current energy provider for specifications on connecting your turbine to their system
- As a source for 100% of your energy — provided you have a good location
Determine your annual energy usage and the amount of annual wind before deciding that a wind turbine is right for you. Companies will provide you with specific estimates and recommendations for your property. Make sure to shop around to find the best model and price range.