A Vertical Helix Wind Turbine Isn't Right For Your Home

A vertical helix wind turbine, as well as the other types of the vertical-axis wind turbine (VAWT) are becoming very popular now but they aren't right for your home and here's why...

First, a couple of definitions so we can agree on what we are talking about:

The rotor shaft of a vertical wind turbine rotates perpendicular to the surface of the earth. The rotor shaft of a horizontal wind turbine rotates parallel to the surface of the earth.

Verticals have been nicknamed "eggbeaters" because of the way they look and horizontal turbines resemble the classic windmill.

Horizontal and vertical wind turbines are similar in the following ways:

1. Same basic components: blade system, generator, controller, and gearbox.

2. Both can be too noisy.

That's where the similarities end.

Here are the pros and cons of vertical wind turbines for the home, so you can decide for yourself:

The advantages of vertical systems are:

1. Verticals handle turbulent flow better than horizontal turbines.

2. Verticals are usually located closer to the ground, so they are easier and cheaper to access when problems arise.

3. They are indifferent to wind direction - they don't have to "find" the wind with a tail

4. Safer for birds and bats.

The disadvantages of vertical windmills are:

1. Cost a lot more.

2. Verticals operate with very high torque, so it's hard to get the blades turning in low-wind conditions.

3. The stresses put on them by the kind of wind they tend to operate in are much greater than with horizontal-axis devices.

4. Efficiency ratings are lower with verticals than with horizontals.

Deeper discussion of the issues:

For small turbines for home use, vertical-axis wind turbines simply aren't as efficient at making power as horizontal-axis systems.

There are 3 main factors that contribute to the inefficiency of the vertical windmill:

1. Lack of aerodynamic assist at turning the "Savonius"-style rotors.

2. Damage-causing stress put on the shaft and bearings because of the higher torque.

3. Vertical-axis windmills tend to be mounted closer to the ground or on roofs where the air is more turbulent. They don't reside in the higher altitude that offers the steady, consistent wind that's energy rich.

More about the first factor - there are 2 major categories of vertical system design:

1. Savonious Rotors, which visually resemble a 55 gallon barrel in some ways, cut in half. Savonius rotor systems are very inefficient (5-10% efficiency) because they have no turning assistance from aerodynamic surfaces. The majority of the new vertical systems are Savonius-type rotors.

2. Darrieus Rotors, which look like an eggbeater. These systems can approach efficiencies of horizontal-axis systems because their blades are designed with aerodynamic properties (they create lift). (Horizontal systems are theoretically capable of up to 59% efficiency.) The vertical helix wind turbine is this type and can demonstrate efficiencies in the 30% range.

Regarding the second factor, efficiency is negatively affected because of the stresses placed on vertical systems and the resulting wear and tear. The way vertical wind turbines are marketed to consumers is that they can be mounted on a roof or very low to the ground, thereby eliminating the added expense of a tower. The low mounting height negatively affects efficiency in two ways:

1. The wind that's close to the ground is turbulent and causes the unit to stop/start and change direction of rotation frequently. This causes mechanical wear on the bearings at the top and the bottom of the rotor shaft, reducing the useful life of the turbine.

2. The way manufacturers compensate for the added wear and tear is to beef-up the materials in the construction of the turbine. This of course makes the turbine more expensive.

And, finally the third factor: the wind close to the ground is chaotic and turbulent because of interference from buildings and trees. That turbulent environment is not anywhere nearly as efficient as a turbine that operates higher up above the tree line. That's where most all the wind energy is - higher up, where there are no obstructions to slow it down or cause it to divert around objects and change direction.

If vertical-axis wind turbines aren't efficient at producing electricity, why are they becoming so popular then?

I believe there are 2 good reasons:

1. They are more aesthetically appealing than horizontal-axis devices. Recent studies in Europe have shown that they are even somewhat hypnotic due to "frequency effect". They sooth like watching waves at the beach have on the human psyche. They don't shift and change directions like horizontals that have a tail do. They just spin. So, we like to look at them do their work.

2. Also, the myth that they can work close to the ground. Theoretically, we think if we could deploy an army of these devices all over roofs, we could solve the energy crisis.

They are simple to put together and get running and they aren't typically mounted on a tower. That makes them appealing to those who want to participate in wind and renewable energy, but don't want the hassle of a major project with a feasibility study to optimize wind, pouring a foundation for a wind tower, and the maintenance costs associated with larger home energy systems.

The bottom line is the vertical helix wind turbine and other vertical-axis wind systems for the home just aren't ready for prime time yet.

If your objective is to create a lot of electrical energy for your home at a price that will allow a payback sooner than the windmill's useful life, verticals are out. The only good choice for now is to buy or build a tried and true horizontal-axis system.

However, if your objective is to get started quickly and start making some electrical energy from wind and you aren't going to obsess over the numbers, vertical helix and other vertical-axis turbines will give make you feel good that you are participating in renewable energy creation and taking some action.

We can only hope that vertical helix wind turbine manufacturers will continue to refine their designs and overcome these negatives. If that happens and they get a lot cheaper, the promise of a "wind turbine on every roof" may be a reality some day.

Roger G. Brown has saved countless companies money on their power bills. Check out Roger's tips on how to save money with wind AND get Free Energy

Peliculas Online

Home Wind Turbine Kits - How Does Wind Start?

Before you seriously think about getting any of the home wind turbine kits, you need to learn a bit about wind. This is study of how the sun affects the earth.

Digging a bit deeper into your wind locally will then tell you if home wind will work for you.

Here's a high-level view of what's happening when you see wind moving the trees:

1. The sun warms the earth

2. The warm earth then warms the cold air above it

3. The warm air rises and is replaced by cool air

That is a 50,000 view of what makes wind happen.

Now, let's go into additional factors that make wind move in the directions it moves in…

1. The sun warms the earth - The earth's surface is very inconsistent. There are rocks, water, soil, buildings, etc. and all absorb and release heat at different rates. This difference in the way these objects radiate heat causes the dissipation to be very uneven. Due to the rotation of the earth, no heating goes on at night. So, the release of heat by the earth is happening at many different rates all over the globe.

As the warm air rises, it expands and takes up more space. It also weighs less making it take up more space and reduced pressure. Low and high pressure air movement causes most of our weather.

2. Warm earth warms cold air - Some air is rising fast and some is rising slowly.

3. Warm air rises and is replaced by cool air - This is the process that creates pressure differences that result in most of our weather. A low pressure area results from summer heating of the ground. Since the temperatures are much greater, the air rises faster. It contains more energy and that's why we see so many thunderstorms in the summer.

The air movement that results from all these forces and physical constraints is wind. The actual pattern of the wind is made more complicated still by the rotation of the earth and the Coriolis Effect. The air wants to sort of stick to the ground and the Coriolis Effect is trying to turn it and break it free.

This is the reason we have cyclical weather phenomenon, like hurricanes and tornadoes.

You need to not only understand the how and why of wind globally, but also locally to judge whether a home wind turbine is a good use of your money.

Pay attention to average wind speed. Yours needs to be 9-12 mph in order to have a really good wind turbine project.

The first step in that process to understanding local patterns is to consult http://www.Wunderground.com. This service has historical weather data and depending on your region, it can give you information on wind averages and directions for years in the past.

Then, double check the data you find online with your own study of wind on your own property at different heights.

You can rent or purchase an anemometer to do that.

The anemometer should be mounted at the height you are considering installing any of the best home wind turbine kits. Leave the device in place for 30 days and assess the data.

If your average is 9 mph or more then you have a viable reason to buy a wind generator.

Roger G. Brown has saved countless companies 10-20% on their utility bills. Check out Roger's tips on how to save money AND get a FREE Energy With Wind.

Peliculas Online