The Evolution Of Wind Turbines

Wind energy, being one of the fastest growing form of clean and renewable energy enjoy a large popularity not only amongst environmentalist. The trend evolved in the latest decade into a new industry and today we all are familiar with the electricity producing huge wind farms.
But there will always be naysayers, and to be faithful to the truth we should look at both sides of the coin:
  • in order to be significantly efficient wind turbines should be really big; this is a place where size does matter.
  • because of their size the costs of building profitable wind turbines are obviously, as big as the machines are.
  • big wind turbines are noisy.
  • wind turbines kill birds.
  • for an aesthetic eye let's just say that wind farms are plain ugly.

There is some truth in all this.
But then again, the wind energy industry is a young one, still in evolution. Its potential is far from being exhausted, and their supporters far from being discouraged. So i feel it is my duty to bring forward the latest wind turbines designs, the ones who answer most of, if not all, above complaints.

The Beauty

The true beauty of the wind turbines is without a doubt the Helix Wind turbine. With her white fluid forms, the Helix turbine is smaller, lighter and much less expensive than the traditional steel propeller turbines. Here are only some of the incredible advantages of this innovative turbine:
  • perfect for low wind speed areas as well as urban areas
  • doesn't have to shut down in high wind speed and no loss of efficiency or power collection due to wind direction change
  • high efficiency due to improved aerodynamics
  • silent even at high wind speed
  • visible to birds and bats
  • aesthetically attractive

And if the picture doesn't convince you, take a look the Helix wind turbine in action.

The Practical

Windspire Turbine, produced by Mariah Power is an affordable, smart and very quiet innovative wind turbine. Inspired by a 3000 years old Egyptian windmill design, the Windspire proved to be competitive with modern wind turbines. At only 30 feet tall and 4 feet wide, the Windspire 1.2 kW wind turbine is distinguished by its sleek propeller-free design and ultra quiet operation.
Already spreading not only in the US but in Europe as well, Windspire seems to be the best solution for homes, schools, small businesses or community gathering spaces.

Watch the Windspire at work in the video bellow.

The Futuristic

With Maglev Wind Turbine the future is not only here, but is also looking great. Maglev Wind Turbine is a modern marvel of engineering which uses an unique combination of science and technology to create an extremely efficient and powerful wind generator. A key advantage of this system is the use of magnetic levitation to reduce friction and increase the power output.
Presented for the first time at the Wind Power Asia Exhibition in Beijing, Maglev Wind Turbine is expected to take wind power technology to the next level.

To watch a video demonstration of the Maglev Wind Turbine visit their website here.

The Aero-Optimized

Compared with the other aerodynamic models presented here, the Aerotecture Wind Turbine seems a little overdone, but what do i know? Its builders at Aerotecture International call this wind turbine a visionary technology and their vision is stated as followed:

  • where wind farms are big, we are small
  • where wind farms are rural, we are urban
  • where wind farms avoid buildings, we attach to them
  • where wind farms seek single monster units, we deploy many units
  • where wind farms are hundreds of miles from their 'users', we are right there
All in all, the Aerotecture wind turbine and the traditional propeller wind turbine are on the completely opposite side of the spectrum as design is regarded.

For more information visit Aerotecture International Official Website.

The Ugly Duck

Without intending any disrespect this was the first thing crossing my mind when i first saw this Australian prototype.

But just as the ugly duck turns out to be a gracious swan, this prototype became the well known Windpod, truly unique for its applicability and affordability. At only AU$700 a piece, these small-scale wind turbines can be used as horizontal modules forming Winpod walls, on rooftops, on bridges or even on vertical building edges.

Other key characteristics of Winpods include :

• Extremely low noise and vibration.
• Able to operate vertically, horizontally or any angle in-between.
• Able to operate efficiently in gusty and turbulent winds such as typically found in urban environments.
• Able to be modularly mounted onto buildings at low cost in a location where wind is at highest concentration.
• Excellent power production per dollar of cost.
• Slender, elongated tubes of only 0.45m diameter.
• Being only 450mm diameter, should not require Council planning approvals.

To learn more about the Winpods visit their official website here.

Digg my article


Wind Turbine Components

Wind turbines come in many sizes and configurations. But no matter if they are big or small, horizontal-axis or vertical-axis, every wind turbine function on the same principle: extracts energy from wind, transfers this harvested energy into a spinning shaft which turns an alternator or generator to produce electricity.

So the basic components of a wind turbine are:
  • Blades or rotor, which converts the energy in the wind to rotational shaft energy.
  • Nacelle that houses a drive train, usually including a gearbox, a generator , support bearings and some other parts.
  • Tower, that supports the rotor and the drive train.
  • Ground-mounted electrical equipments, including electrical cables, controls and interconnection equipment.

Most traditional wind turbines have three large steel blades, but the rules are not set in stone. New blade designs and materials are constantly experimented and sometimes proven more efficient than the traditional ones.

The power available to harvest from the wind largely depends on both the wind speed and the area that is swept by the turbine blades.
  • for a double wind speed the energy available increases by a factor of 8.
  • for a double rotor diameter the energy available increases by a factor of 4.

However is not possible to harvest all the energy and turn it into electricity. By the Betz Limit formula there is a maximum of 59.26% that can be extracted from the available power. Also no alternator or generator is 100% efficient in converting the energy into electricity, and factors like friction, magnetic drag and electrical resistance losses will further reduce the wind turbine efficiency.
This means that no small wind turbines are 100% efficient even when running at maximum speed.

This is the reason why the rotor diameter and the generator model are the most important factors when choosing a wind turbine model. Hopefully realistic expectations will help you make the right choice and avoid unsubstantiated claims and products.

For more information check out How To Build A Wind Generator Guide.


Is Building a WindTurbine Worth The Trouble?

All things considered, i would say that building your own WindTurbine is a well worthy project. In my opinion it is fun, interesting and depending on how technically skilled you are, can save you some money on electricity bills. Most people would start their first DIY green energy adventure with a solar panel, but wind turbines are cheaper and easier to build.

First thing you have to consider is, of course, how much wind is there for you to exploit. A good place to find out about your local winds, no matter where you live in the world is the Wind Maps website.

If you have enough wind - at least 20 km per hour most of the time - and decided on all other things described in Domestic WindTurbine article like the type of wind turbine, its size and location, then is time to decide for yourself if building a wind turbine is worth the trouble. How much will cost you, what kind or technical skill is required and what results to expect; all this can be learned from other people experiments before you even start.

And here are some good free building guides, the best i could find over the internet.

1."How I built an electricity producing wind turbine" Guide

A guy who wanted - and succeed - to build a wind turbine to produce electricity for his remote property. The guide is few years old but the step-by-step process is still relevant. In his own words he produced energy:
"Not with an expensive, store-bought turbine, but with a home-built one that cost hardly anything. If you have some fabricating skills and some electronic know-how, you can build one too."
What he got is a small wind turbine producing around 14.00 volts at the cost of $140. Not bad, i would say, and definitely worth taking a look.
Read more at How i home-built an electricity producing wind turbine website.

2."Large 17' Diameter Homebrew Turbine" Guide

Twenty years of wind turbines hobby and a lot of wind projects in this website for you to learn a great deal about the process of building wind turbines. The costs of this wind machine are not clearly stated but it looks a lot more expensive than the previous one. Also the amount of work and knowledge required is more serious as he build everything from the scratch.

All in all the website is interesting, fun and a must read if you really want to understand the wind turbines basic principles.

3."Build A WindTurbine" Guide

Already at the third project, MK-III, the guide starts with a small wind turbine made mostly of wood or MDF and gradually progress to a better design and efficiency. You will find here step-by-step instructions, plans to download and some videos. Claiming to be "the home turbine builders community" they also have a very useful forum where you can ask questions and get answers from more experienced people.

An interesting reading in your free time, mostly for what to avoid when building a wind turbine, check out the Build A Wind Turbine website here.

A family living off the grid for more than 15 years share their experiences and successes with everybody in their guide, as well as the challenges encountered. Less technically demanding and more practical then the previous guides, they will teach you to build an efficient wind turbine for under $100 and produce over 1000 watts of electricity.

Note: this guide is not free, but for $19.97 you can save a lot of time and frustration when building your wind turbine. You can download the free preview copy of the Living Off The Grid guide here to have an idea of what to expect.


Domestic WindTurbine

Wind turbines harness the power of the wind and use it to generate electricity. One of the greatest advantages of wind energy is that it can be used both on a large and small scale. Small wind energy systems known as domestic wind turbines or "microwind" turbines are ideal for householders to produce electricity.

Wind turbines use large blades to collect the wind’s kinetic energy. When the wind blows the blades are forced to turn, driving an electric generator to produce electricity. The stronger the wind, the faster the blades turn and the more is electricity produced. Thanks to their flexibility small wind turbines can be installed in most locations.

Types of Domestic Wind Turbines

Based on the direction of the rotating shaft there are two kind of wind turbines used today:

  • Horizontal-axis wind turbines. A typical horizontal-axis have three blades like airplane propellers and the amount of energy produced is dependent on their size. One of the biggest horizontal-axis turbine in the world have blades longer than a football field, and produce more than five million watts, enough to power 1,400 households.

  • Vertical-axes wind turbines. Vertical-axes wind turbines have blades that run from the top to the bottom. They can have different shapes, but the most common type is the Darrieus wind turbine, named after his French inventor (see image).

Based on their installation location there are also two types of domestic-sized wind turbine:

  • Mast mounted: these are free standing and are erected in a suitably exposed position, the classical wind turbine that we see everywhere.

  • Roof mounted: these are smaller than mast mounted systems and can be installed on the roof of a home where there is a suitable wind resource.

Domestic WindTurbine Requirements

If you are considering renewable energy for your home and think that a domestic WindTurbine can be suitable for you, first thing you have to do is find out if your location is windy enough. Generally a wind turbine needs at least 20 km per hour most of the time to run productively. Here is the US Wind Resource Map where you can find out about your location winds.

The actual wind speed at your site will be influenced by the local topography and any nearby obstruction, so here are few more factors to consider:

  • Any large obstacles like buildings, trees or hills near your home can obstruct the wind or produce turbulence.
  • Urban areas winds can be very fickle because of the buildings, so roof mounted wind turbines prove to be more effective than mast mounted turbines.
  • The higher a wind turbine is installed the stronger the winds will be and the more energy will be produced.
  • Small domestic wind systems normally do require permission from your local authority, so check before you install a system.
It is possible to build and install your own WindTurbine , but we recommend to approach this task with caution. If you are interested to explore this topic check out this useful How To Build A Wind Generator Guide.

Domestic Wind Turbines Size

The height of a wind turbine varies according to wind turbine models, but generally a range of 5-10 m height from top to bottom for stand-alone turbines is ideal. The higher the tower, the higher the average wind speed that the turbine will experience and the smoother the wind.

The size of the rotor diameter will also vary according to wind turbine model. To power a modern home on a windy enough site the blades would need to span about 5 m from tip to tip. With careful planning and some energy conservation improvements a smaller machine may suffice.

As for the space needed for a wind turbine, they should be placed as far away as possible from trees, buildings or other obstacles (at least 10-20 m) and above the height of nearby buildings. As a guide, the wind turbine should be about twice the height of obstructions in the immediate front of it.

For rooftop mounted turbines the height of the tower is less important since they will be above the nearby buildings anyway; yet they should be installed with care so that the vibrations will not be transmitted to the house.

Domestic Wind Turbine Maintenance

The maintenance required for small wind turbines is minimal; generally an annual check is all that it needs. The lifetime of a typical WindTurbine is about 20 years.

How To Build A WindTurbine For Your Home or Your Busines.


Why WindEnergy?

The increasing pressure of global warming combined with the constant rising price of fossil fuels forces us to come up with new ways to produce energy.
Using the power of wind is not new for us; there is evidence that wind energy was used to propel boats along the Nile as early as 5000BC. But only recently we started to use the wind power to create electricity.

Wind energy is actually based on solar energy; about one to three per cent of solar energy reaching the Earth is converted into wind energy. Therefore it is a clean, renewable form of energy and the advantages of using it are obvious.

On a large scale wind energy is converted to high voltage electricity with the help of wind farms. Compared to the environmental effects of traditional energy sources, the environmental effects of wind power are relatively minor. Wind energy emits no air pollution and consumes no energy, unlike fossil fuel power sources. According to the Department of Energy, offshore wind farms could provide enough energy to power the entire nation.

On a small scale wind turbines can be build and installed for personal use by anyone with less than minimum technical skills. Once installed it is one of the cheapest forms of electricity generation to maintain.

Today Germany is the world leader producer of wind energy, with US on the third place. In Denmark, wind power now produces approximately 20% of the country's electricity consumption, and in recent surveys, 90% of the citizens wanted more wind turbines installed. The United Kingdom plans to use offshore wind turbines to generate enough power to light every home in the U.K. by 2020.

The most serious environmental drawbacks to wind machines may be their negative effect on wild bird populations and the visual impact on the landscape. But not for everyone; in the UK, repeated opinion surveys have shown that more than 70% of people either like, or do not mind, the visual impact.

However, wind is the fastest growing energy source worldwide. The drawback is very little when compared to what is gained and the world is starting to realize that.