The Complete Guide
You’re driving down the highway, enjoying the warm breeze ruffling your hair, when you round a bend and are met with an awesome sight: a field of massive pinwheels rising a hundred feet into the air, the giant contraptions spinning lazily in the summer sun.
While it may sound like a scene from a science fiction novel, many people around the world are no longer surprised to see huge wind turbines dotting the landscape. In the past few decades, harnessing electrical energy from the wind has moved from fantastical to commonplace; in fact, all the wind turbines installed by the end of 2019 can cover more than 6% of the entire world’s demands for electricity.
But even though wind turbines are gaining ground as leaders of the renewable energy movement, most people still know little about them. How do wind turbines work? What makes them different from windmills? And why do they have to be so, well, big? This article will answer all of these questions and more as we journey from the early days of wind energy into its bright and hopeful future.
The Early Days of Wind Energy
Humans have been harnessing the energy of the wind for millennia; after all, the first people to use sails on their boats took the wild power of the wind and tamed it to make sea voyages possible.
Perhaps the most widely known usage of wind energy comes in the form of windmills. For many, windmills conjure images of the tulip fields of Amsterdam, or the chivalrous Don Quixote from Cervantes’ popular 17th century novel. And while windmills do seem inherently connected to 17th and 18th century Europe, they have actually been used by hundreds of civilizations spanning thousands of years.
The first recognizable windmill designs do originate in the 17th century; the 17th century BC, that is! The Babylonian emperor Hammurabi, famous for his judicial ‘Code of Hammurabi,’ came up with designs to use wind power to help irrigate farms. While there isn’t any archeological evidence that any of his planned windmills were ever built, Hammurabi’s designs represent the first attempt to use wind to generate mechanical energy.
Greece (Heron of Alexandria)
After Hammurabi, windmills don’t appear again in the historical record until 67 AD, when a Greek inventor and mathematician began his career. Heron of Alexandria was also known as the Hero of Alexandria for his impressive work compiling the math and engineering knowledge of ancient Babylonia, Egypt, and the Greco-Roman empires. Heron was a brilliant inventor; not only did he construct the first working windmill, he also drew up plans for the world’s first steam engine, the aeolipile.
The Middle East and Western Asia
In the 7th century AD, the first ‘commercial’ windmills were built in Sistan, Afghanistan. These windmills were easily recognizable, with vertical axles and rectangular blades covered in cloth or reed ‘sails.’ These windmills were primarily used for grinding corn or drawing water, but were also eventually used to process wheat and sugarcane.
Modern-day Iran also boasts some of the world’s earliest windmills, with their design most likely originating in eastern Persia between 500-900 AD. Examples of these windmills, called ‘Asbads,’ are located in the small town of Nashtifan, and are still in operation today. The current operating mills have been used for several centuries, and can even withstand wind up to 74 miles per hour. Iranian windmills were (and still are!) used to grind corn into flour, and serve as windbreaks – protection for the town against the fierce desert winds.
Eventually, the windmill design migrated to Europe, where it became a staple of both food production and culture. Most Europe windmills were used to grind flour, and were introduced beginning around 1180 AD. Windmills can still be found in the following European countries:
- United Kingdom
The Netherlands is perhaps the country best known for its windmills. While most European mills converted wind energy into mechanical energy used to grind grain, Dutch windmills served a different purpose. Much of the Netherlands sits below sea level, which left the land marshy and unusable. As a solution, Dutch windmills were introduced to pump water out of the low-lying lands and back behind the raised dikes of river beds, allowing the former marshland to be farmed productively. While many of the Dutch windmills pumped water, several also ground grain into flour, and a few even served as wind-powered sawmills to cut wood.
Carrying on in the grand tradition of Dutch windmills, most of the windmills that migrated to the United States were used as water pumps. Windmills have been used in the United States since 1854, when a man named Daniel Halladay began making them in his Connecticut machining shop. Windmills were particularly useful for pumping water along the western frontier, and U.S. wind-powered pumps were crucial in the development of the continental railroad.
The Switch to Wind Turbines
While wind energy proved invaluable to numerous early civilizations, humanity had just scratched the surface of the power wind could provide. Windmills were excellent at converting the kinetic energy of the wind’s motion into the mechanical energy needed to grind corn or pump water. But the world was about to enter a new age, where the dependence on mechanical energy would be replaced by a demand for a new type of energy: Electricity.
Faraday’s Law of Induction
In 1831, an English scientist named Michael Faraday made a world-changing discovery. Through careful experimentation, Faraday found that moving a magnet around a coil of wire could produce an electrical current. This process came to be known as ‘Faraday’s Law of Induction,’ and forms the basis of the scientific field known as Electromagnetism.
Faraday’s Law of Induction grew into much more than a simple idea. Expanding on induction, Faraday next created a new invention called a dynamo, which was the very first electrical generator. And with the birth of the electric generator, it was only a matter of time before Faraday’s Law of Induction would come to change the humble windmill.
Cleveland, Ohio – 1888
More than 50 years after Michael Faraday created the first electric generator, a brilliant inventor named Charles F. Brush combined the laws of electromagnetism with the basic principles of the windmill to create the first electrical turbine.
As an inventor, Brush was best known for his work on arc lamps and commercial lighting systems. Brush had been fascinated with electricity his entire life; in fact, he built his first static electric machine when he was only 12, and built his first arc light when he was in high school!
Because of his fascination with electrical energy, it was only natural that Brush would want his home to be electrically powered. In 1888, Brush constructed a massive wind-powered electric generator to provide electricity to his mansion in Cleveland. The turbine was several stories tall, with a rotor diameter of 50 feet across, and a sail of 1,800 square feet. The wooden turbine ran for 20 years, charging the batteries with which Brush powered his mansion, though it was too heavy to be very energy efficient.
Brush’s wind turbine represented the first marriage of wind and electrical power, and formed the basis for many later iterations of the wind turbines we use today. A later inventor, Poul La Cour from Denmark, would improve upon Brush’s design to make a wind turbine that was much lighter and more efficient.
The 1973 Oil Crisis
While there was a precedent for wind turbines, the concept didn’t really take off until the early 1970’s. In October of 1973, an oil embargo on the United States led to an oil crisis that shook up the energy industry of the country. With severe shortages of oil throughout the nation, several states chose to look more closely at renewable energy options.
While federal funding for renewable energy projects dropped off during the 1980’s, California, especially, continued to focus on wind power as a potential energy source of the future. Europe also began heavily investing in the industry, and by 2000, Europe led the world in wind energy capability.
Wind Power Today
In the past several decades, the demand for clean energy sources has grown throughout the world. Rising levels of greenhouse gasses and severe weather disasters have prompted many countries to look more closely at the sources of their electrical power.
In Europe, onshore wind energy is currently the cheapest form of renewable power generation, and accounted for 44% of all new power installations across the continent in 2020.
The United States has implemented a federal set of wind energy incentives to encourage states and cities to develop wind power plants in place of fossil fuel electrical energy sources. Throughout the world, wind energy is coming into its place as a viable contender in the electrical energy market.
How Does a Wind Powered Generator Work?
Wind turbines, or wind-powered generators, work much the same way any other electrical generator works. Using Faraday’s Principles of Electromagnetic Induction, electrical generators use a rotating coil of wire and a magnet to create electrical energy.
The genius behind using a wind turbine as an electrical generator lies in the fact that turbines were built to spin. Think of the images you’ve seen of windmills or wind turbines: large blades stick out into the air, catching the wind like sails on a boat and spinning around in circles. As the blades ride the wind, they rotate an inner rotor, which turns a set of gears inside a protected space. In windmills, the spinning gears could be hooked up to a water pump, a grind stone, or even a saw. In wind turbines, the spinning gears connect to an electrical generator.
The electrical generator that sits inside a wind turbine is nearly the same as the first dynamo invented by Michael Faraday. Magnets and coils of wire spin past one another, which induces an electrical current. This current of electricity can be stored in batteries, or immediately transferred into the electrical grid where it zooms along wires until it enters your television or lightbulb at home.
Different types of electrical generators have different levels of efficiency. When it comes to wind power, there are a few things to consider where efficiency is concerned:
- High winds produce more power – up to a certain point. If the wind is too strong, it can damage the turbines.
- Wind speeds are faster at higher altitudes
- Older turbines tend to be less efficient than newer models
On average, most turbines extract about 50% of the energy that passes through the rotor area. While that may not sound like a great efficiency score, coal powered energy plants are generally only 33% efficient. Newer models of wind turbines are likely to increase in efficiency, making them even more attractive alternatives to traditional fossil-fuel powered electrical plants.
Yes, that is what they’re called! Most wind ‘power plants’ are actually referred to as wind farms, in large part because they take up a lot of wide, open space. In addition, wind farms technically ‘harvest’ wind by collecting it and turning it into something useful. Wind farms are often massive; some turbine models can require nearly 100 acres around each individual tower for optimum wind collection! The larger a wind farm is, the more power it can produce for the electrical grid. In addition, larger wind farms tend to be more cost-effective to run than their smaller counterparts.
Wind farms are a common sight in some communities, but are conspicuously absent in others. In many cases, it’s just not practical to put in a wind farm at a particular location. The area must have consistent winds within a safe speed range for the turbines, and needs lots of space surrounding the farm to allow the turbines to operate efficiently. With that being said, there are plenty of areas that would be perfect for wind energy that haven’t yet been used.
Below is a list of some of the largest wind farms in the world. Each of these farms produces more than 500 megawatts (MW) of electrical energy, or 500 million watts. For perspective, many lightbulbs are 60 watts, so a 500 MW wind farm could power over 8 million light bulbs.
Jiuquan Wind Power Base, China
Capacity: 20 GW (20 billion watts; over 300 million light bulbs)
Jaisalmer Wind Park, India
Capacity: 1,600 MW (1.6 billion watts; over 26 million light bulbs)
Alta Wind Energy Centre, California (US)
Capacity: 1500 MW (1.5 billion watts; 25 million light bulbs)
Muppandal Wind Farm, India
Capacity: 1500 MW (1.5 billion watts; 25 million light bulbs)
Shepherds Flat Wind Farm, Oregon (US)
Capacity: 845 MW (845 million watts; over 14 million light bulbs)
Roscoe Wind Farm, Texas (US)
Capacity: 781 MW (781 million watts; over 13 million light bulbs)
Horse Hollow Wind Energy Centre, Texas (US)
Capacity: 735 MW (735 million watts; over 12 million light bulbs)
Capricorn Ridge Wind Farm, Texas (US)
Capacity: 662 MW (662 million watts; over 11 million light bulbs)
Walney Extension Offshore Wind Farm, UK
Capacity: 659 MW (659 million watts; 11 million light bulbs)
London Array Offshore Wind Farm, UK
Capacity: 630 MW (630 million watts; over 10 million light bulbs)
Types of Wind Farms
While most wind farms look similar, with only slight variations in size or model of wind turbine, there are two major categories of wind farm to keep an eye out for: onshore and offshore.
The majority of wind farms are onshore, meaning they’re built on land. Building wind turbines on land is nothing new, and there are plenty of windy plains and mountains available for harnessing wind power.
A new trend, however, has been to construct wind farms offshore. While offshore construction can be pricey, it has numerous benefits, and can tap into consistent and powerful oceanic winds to produce electrical energy. Offshore wind farms also expand the available space we have to use; after all, 71% of the earth is covered in water.
Can You Harness Your Own Wind Energy?
The short answer is, of course! Wind generators aren’t all that complicated to build or maintain, and there are even companies that will install a system for you. In fact, wind energy is right up there with solar panels when it comes to home electricity production. If you’re looking into your own little wind farm, here’s what you’ll need to know:
Wind Energy Basics
Home wind turbines operate on the very same basis that large, industrial models do: mounted blades turn a generator, which produces electrical energy. All wind generators require 5 basic things:
- A generator
- Blade mounting
- A tower
- Batteries and a control system
If you want to follow in Faraday’s footsteps and make your own electrical generator from scratch, go for it! For a bit easier DIY wind turbine, however, you should be able to purchase all the pieces you need for a turbine and put it all together.
A good option for a generator is actually a permanent magnet, DC motor. Turning the shaft of the motor will produce a good amount of electrical energy, especially if you purchase a larger voltage motor.
It’s also easy to purchase pre-fabricated blades for your wind turbine, or make some yourself. Common blade materials include wood or PVC pipe. The blades attach to a hub that fits on the motor shaft, and the hub and motor are attached to a long piece of wood called the blade mounting that holds everything together.
Once the mounting is set, you’ll want to elevate your turbine to catch as much wind as possible. The height of your tower will depend on where you’re placing your turbine and how much wind you usually get. You will want to make sure you follow any height restrictions in your area (some areas won’t let you build above a certain height, especially in residential locations). The last thing you’ll need to do is wire up the generator and attach a charge controller to make sure all the electrical parts keep doing what they’re supposed to. Because wind energy is so prolific, you can easily purchase a controller system pre-fabricated online. You can also choose to put the circuit board together from scratch; there are plenty of online sources with detailed electric schematics to help guide you.
If you want to have a home wind turbine but don’t want to go through all the hassle of putting one together yourself, don’t despair! You can buy an entire wind turbine for a few hundred bucks, or splurge and go for a super fancy system that prices at around $1000. Most prefabricated turbines are meant to be attached to the roof of a house, so if you’re wanting to use them in the middle of field, you may have to build or purchase a separate tower from which to mount the turbine. You can also look into commercial, alternative energy companies who will install a complete wind energy system for you, tower and all.
Things to Consider in regards to Wind Turbines
Before you purchase (or build!) a wind turbine, there are a few things you should think about:
What will you be using your turbine to power? The more power you want, the bigger your turbine will have to be. And while some turbines are portable, (to be used for camping, emergencies, etc.) portable wind turbines are also much smaller.
While a couple hundred bucks isn’t necessarily a big deal, some wind turbines can be pricey to install. And don’t forget that machines require money to maintain: oil, mechanical fixes, and unexpected circumstances might cost more month-to-month than you were expecting. And a single wind turbine probably won’t produce enough electricity to power your entire house, so you’ll want to consider whether any energy savings will be enough to cover the installation and operating costs.
This one is a must: if your house doesn’t get any wind, then don’t install a wind turbine! You can check online for the average wind in your area, or you can just keep track yourself over a certain period of time. Remember, you aren’t looking for gale force winds: consistent, low levels of wind will work better to produce energy than large, dangerous storms. And if your area is prone to severe weather, you’ll want to make sure you install a robust wind turbine that can withstand inclement weather without becoming damaged.
The Pros of Wind Energy
Wind energy is an incredible resource. Over the past few decades, it’s played a much larger role in world energy production than it has in previous years. And the forecasts continue to be optimistic: some experts report that wind energy could provide 20% of US electricity by 2030, and 35% by 2050. Why the sudden push for wind energy? What does it provide that other sources of energy do not?
One of the biggest perks of wind energy is that it’s a renewable resource. Unlike fossil fuels that are considered a limited resource, wind is constantly available, and will be even in the distant future. While not all areas get much wind, the earth as a whole has a wind power potential of 840,000 TWh (terra-watt-hours) of electricity every year. Each year the earth uses around 22,347 TWh, which means that wind energy could potentially power the entire earth nearly 40 times over!
Wind turbines are also a very clean source of electrical energy. Unlike fossil fuels, wind produces minimal amounts of greenhouse gas emissions. Wind energy is also water-friendly; if 35% of US electricity was wind-generated by 2050, water use in the energy sector would decrease by 15%.
Partly due to their long history, wind turbines tend to be more acceptable in communities than other alternative energies (think nuclear power plants). While there are documented cases of wind turbine accidents, wind turbines are generally considered safe: they don’t cause cancer, they don’t smell, and they look pretty cool!
Tax Benefits to Companies and Consumers
As a way to increase alternative energy production, many countries are implementing tax benefits for the construction of new wind farms around the world. Home consumers that choose to include wind energy on their property may also receive financial benefits or tax breaks to help offset the cost of installation.
Excellent Domestic Energy Option
One of the big benefits of wind energy is its ability to provide local power. Wind potential exists in every country in the world, so there’s no need to look globally for extra energy (as is often needed in the case of oil or coal). Wind farms can also provide a boost to local jobs, which makes wind energy a wonderful domestic energy option.
Wind energy is one of the lowest-priced energy sources available, costing only 1-2 cents per kwh (kilowatt-hour) to produce. Not only is wind energy cheap, but it’s sold at a fixed price over long periods of time, without needing to rely on external fuel prices to gauge profitability. That means that wind power can also help mitigate some of the price volatility that the energy market currently experiences due to the dependence on oil and petroleum products.
The Cons of Wind Energy
Of course, wind energy isn’t perfect. As with any energy source, wind comes with a list of cons that need to be seriously considered as wind harnessing technology grows in prevalence:
Bird and Bat Danger
Perhaps the most publicized downside of wind energy is the danger wind turbines pose to bird and bat populations. It’s estimated that between 140,000 to 500,000 birds are killed each year by wind turbines in the United States. Wind turbines have also been shown to pose a danger to bats, especially if the turbines are placed in the path of migration zones. While wind turbines kill far fewer birds than collisions with windows do (300 million deaths per year), it’s important to note the danger turbines can pose to other species.
While generating wind energy is very cost-effective, it’s pricey to get a wind farm up and running. Most commercial-scale wind turbines cost $3-$4 million dollars apiece to install, so massive wind farms can be immensely expensive, even for large governments. Although the demand for renewable energy is high, many governments and businesses don’t want to foot the upfront cost of building a new wind farm when they have older, fossil-fuel power plants they can fall back on.
Even though wind turbines have a very low carbon footprint when it comes to their emissions, they aren’t exactly carbon neutral, either. Operating a wind farm requires plenty of oil to grease the mechanical parts of the machine, not to mention the materials required to build the 100-foot-tall turbines in the first place.
Aesthetics and Noise
Wind turbines don’t always make good neighbors; while the sight of a field of turbines can be beautiful to some people, others find the view distasteful. And of course, wind turbines don’t operate silently. Turbines can create both a mechanical hum produced by the electrical generator, and a ‘whooshing’ noise produced by the spinning blades cutting through the air. While any new wind farms have to take potential sound into account, many residential areas oppose the installation of wind turbines nearby, worried that the generators might lower both the property value of their homes and their quality of living.
So, Is Wind Energy Worth It?
Even though wind energy comes with plenty of cons, it’s still an important energy resource to be tapped for the future. Most new turbine models are designed to help mitigate some of the cons of wind energy: blade shape is changed to minimize any noise; the location of wind farms is reevaluated to move out of a bird species’ migration path; new materials are used that bring down the cost of installing a turbine.
The Future of Wind Energy
While the future is uncertain, we may already have a possible glimpse at the next evolution of the wind turbine. A Spanish company founded in 2010 is pushing for a new type of wind turbine – without spinning blades.
Bladeless Wind Turbines (The Vortex)
Vortex Bladeless doesn’t use the spinning energy of rotating turbine blades to produce electrical energy; instead, this company’s turbine stands like a pencil, straight up into the sky, and vibrates as the wind passes over it. The Vortex takes advantage of a concept known as vorticity, a measure of local rotation in a fluid flow. In engineering and meteorology, air is classified as a fluid based on its behavior. Vorticity is like a measure of the spinning speed of different parts of air, and the Vortex turbine harnesses that motion and converts it into electrical energy. As the Vortex vibrates, it nudges a pair of magnets sitting at its base, which amplifies the frequency of oscillation to maximize the efficiency of the machine. While the Vortex still uses the basic Laws of Electromagnetic Induction to produce electrical energy, the motion it taps into is very different: side-to-side vibration of the turbine, rather than the spinning motion of the turbines we’ve used up to this point.
One of the most obvious benefits of the Vortex turbine is that it doesn’t have any spinning blades. Not only is that good news for passing birds, it also makes upkeep on the turbine much easier (and cheaper). The Vortex is also much smaller than traditional turbines, with current plans standing at only 41 feet tall. The Vortex is also completely silent, and costs 50% less to manufacture and install than a traditional turbine.
While the Vortex turbine is still in the developmental phase, bladeless turbines may very well be the wind harnessing machines of the future. Right now, we’re still using wind turbines that look remarkably similar to their windmill ancestors. What might the future hold for wind energy?